AFLAC INC, 10-K filed on 2/25/2019
Annual Report
v3.10.0.1
Document and Entity Information - USD ($)
 12 Months Ended
Dec. 31, 2018
Feb. 12, 2019
Jun. 30, 2018
Entity Registrant Name Aflac Incorporated    
Entity Central Index Key 0000004977    
Document Type 10-K    
Document Period End Date Dec. 31, 2018    
Document Fiscal Year Focus 2018    
Amendment Flag false    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --12-31    
Trading Symbol AFL    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 33,002,565,252
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   750,332,375  
v3.10.0.1
Consolidated Statements of Earnings - USD ($)
shares in Thousands, $ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Revenues:      
Net premiums, principally supplemental health insurance $ 18,677 $ 18,531 $ 19,225
Net investment income 3,442 3,220 3,278
Realized investment gains (losses):      
Other-than-temporary impairment losses realized (81)    
Other-than-temporary impairment losses realized   (37) (85)
Other gains (losses) [1] (349) (114) 71
Total realized investment gains (losses) (430) (151) (14)
Other income (loss) 69 67 70
Total revenues 21,758 21,667 22,559
Benefits and expenses:      
Benefits and claims, net 12,000 12,181 12,919
Acquisition and operating expenses:      
Amortization of deferred policy acquisition costs 1,245 1,132 1,141
Insurance commissions 1,320 1,316 1,368
Insurance and other expenses [2] 2,988 2,780 2,796
Interest expense 222 240 268
Total acquisition and operating expenses 5,775 5,468 5,573
Total benefits and expenses 17,775 17,649 18,492
Earnings before income taxes 3,983 4,018 4,067
Income Tax Expense:      
Current 1,379 631 884
Deferred (316) (1,217) 524
Total income tax expense 1,063 (586) 1,408
Net earnings $ 2,920 $ 4,604 $ 2,659
Net earnings per share:      
Basic (in dollars per share) $ 3.79 $ 5.81 $ 3.23
Diluted (in dollars per share) $ 3.77 $ 5.77 $ 3.21
Weighted-average outstanding common shares used in computing earnings per share (In thousands):      
Basic (in shares) 769,588 792,042 822,942
Diluted (in shares) 774,650 797,861 827,841
5.50% subordinated notes due September 2052      
Expense on extinguishment of debt   $ 13  
Senior Notes due 2039 and 2040      
Expense on extinguishment of debt     $ 137
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[2] Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt
v3.10.0.1
Consolidated Statements of Comprehensive Income (Loss) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Statement of Comprehensive Income [Abstract]      
Net earnings $ 2,920 $ 4,604 $ 2,659
Other comprehensive income (loss) before income taxes:      
Unrealized foreign currency translation gains (losses) during period 232 286 283
Unrealized gains (losses) on investment securities:      
Unrealized gains (losses) on fixed maturity securities during period [1] (3,155) 1,731 2,852
Reclassification adjustment for realized (gains) losses on fixed maturity securities included in net earnings [1] 46 2 (53)
Unrealized gains (losses) on derivatives during period 2 1 3
Pension liability adjustment during period (25) 9 (45)
Total other comprehensive income (loss) before income taxes (2,900) 2,029 3,040
Income tax expense (benefit) related to items of other comprehensive income (loss) (797) 631 1,035
Other comprehensive income (loss), net of income taxes [2] (2,103) 1,398 2,005
Total comprehensive income (loss) $ 817 $ 6,002 $ 4,664
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[2] All amounts in the table above are net of tax.
v3.10.0.1
Consolidated Balance Sheets - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Securities available for sale, at fair value:    
Available for sale, fixed maturity securities [2],[3] $ 82,895 [1],[4] $ 84,313 [5]
Securities held to maturity, at amortized cost:    
Held to maturity, fixed maturity securities 30,318 31,430
Equity securities, at fair value:    
Equity securities [2],[3],[6] 987  
Available for sale securities, equity securities   1,023
Other investments [7] 7,706 3,402
Cash and cash equivalents 4,337 3,491
Total investments and cash 126,243 123,659
Receivables 851 827
Accrued investment income 773 769
Deferred policy acquisition costs 9,875 9,505
Property and equipment, at cost less accumulated depreciation 443 434
Other [8] 2,221 2,023
Total assets 140,406 137,217
Policy liabilities:    
Future policy benefits 86,368 81,857
Unpaid policy claims 4,584 4,392
Unearned premiums 5,090 5,959
Other policyholders' funds 7,146 6,939
Total policy liabilities 103,188 99,147
Income taxes 4,020 4,745
Payables for return of cash collateral on loaned securities 1,052 606
Notes payable 5,778 5,289
Other [9] 2,906 2,832
Commitments and contingent liabilities (Note 15)
Total liabilities 116,944 112,619
Shareholders' equity:    
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2018 and 2017; issued 1,347,540 shares in 2018 and 1,345,762 shares in 2017 135 135
Additional paid-in capital 2,177 2,052
Retained earnings 31,788 29,895
Accumulated other comprehensive income (loss):    
Unrealized foreign currency translation gains (losses) (1,847) (1,750)
Unrealized gains (losses) on fixed maturity securities [10] 4,234 5,964
Unrealized gains (losses) on derivatives (24) (23)
Pension liability adjustment (212) (163)
Treasury stock, at average cost (12,789) (11,512)
Total shareholders' equity 23,462 24,598
Total liabilities and shareholders' equity 140,406 137,217
Consolidated Entity Excluding Variable Interest Entities (VIE)    
Securities available for sale, at fair value:    
Available for sale, fixed maturity securities [11] 78,429 78,804
Securities held to maturity, at amortized cost:    
Held to maturity, fixed maturity securities 30,318 31,430
Equity securities, at fair value:    
Equity securities [11] 827  
Available for sale securities, equity securities [11]   270
Variable Interest Entity, Consolidated    
Securities available for sale, at fair value:    
Available for sale, fixed maturity securities [11],[12] 4,466 5,509
Equity securities, at fair value:    
Equity securities 160  
Available for sale securities, equity securities   753
Other investments [13] 5,856 2,341
Policy liabilities:    
Total liabilities $ 102 $ 128
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
[4] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[5] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[6] Includes perpetual securities ($62 at fair value)
[7] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
[8] Includes $182 in 2018 and $151 in 2017 of derivatives from consolidated variable interest entities
[9] Includes $102 in 2018 and $128 in 2017 of derivatives from consolidated variable interest entities
[10] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[11] Includes perpetual securities, see Notes 1 and 3 of the Notes to the Consolidated Financial Statements
[12] Includes perpetual securities
[13] Consists of TREs, CMLs, MMLs, and alternative investments in limited partnerships
v3.10.0.1
Consolidated Balance Sheets (Parenthetical) - USD ($)
shares in Thousands, $ in Millions
Dec. 31, 2018
Dec. 31, 2017
Available for sale, fixed maturity securities, amortized cost $ 76,856 [1],[2] $ 75,132 [3]
Held to maturity, fixed maturity securities, fair value $ 36,722 $ 38,072
Common stock, par value (in dollars per share) $ 0.10 $ 0.10
Common stock, shares authorized (in shares) 1,900,000 1,900,000
Common stock, shares issued (in shares) 1,347,540 1,345,762
Asset derivatives $ 417 $ 331
Liability derivatives 387 474
Variable Interest Entity, Consolidated    
Available for sale, fixed maturity securities, amortized cost [4] 3,849 4,538
Asset derivatives [5] 182 151
Liability derivatives [5] 102 128
Consolidated Entity Excluding Variable Interest Entities (VIE)    
Available for sale, fixed maturity securities, amortized cost 73,007 70,594
Held to maturity, fixed maturity securities, fair value 36,722 38,072
Loan receivables and limited partnerships | Variable Interest Entity, Consolidated    
Other investments held in unit trust, net of reserves, amortized cost $ 5,856 $ 2,341
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[4] Includes perpetual securities
[5] Consists entirely of derivatives
v3.10.0.1
Consolidated Statements of Shareholders' Equity - USD ($)
$ in Millions
Total
Common stock:
Additional paid-in capital:
Retained earnings:
Accumulated other comprehensive income (loss):
Treasury stock:
Balance, beginning of period at Dec. 31, 2015   $ 135 $ 1,760 $ 24,007 $ 625 $ (8,819)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Exercise of stock options     46      
Share-based compensation     64      
Treasury stock reissued     38     69
Net earnings $ 2,659     2,659    
Dividends to shareholders ($1.04 per share in 2018, $.87 per share in 2017 and $.83 per share in 2016)       (685)    
Unrealized foreign currency translation gains (losses) during period, net of income taxes         213  
Unrealized gains (losses) on fixed maturity securities during the period, net of income taxes and reclassification adjustments [1]         1,819  
Unrealized gains (losses) on derivatives during period, net of income taxes         2  
Pension liability adjustment during period, net of income taxes         (29)  
Purchases of treasury stock           (1,422)
Balance, end of period at Dec. 31, 2016 20,482 135 1,908 25,981 2,630 (10,172)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2016-01 [1]       0 0  
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2018-02 [1]       0 0  
Exercise of stock options     38      
Share-based compensation     51      
Treasury stock reissued     55     51
Net earnings 4,604     4,604    
Dividends to shareholders ($1.04 per share in 2018, $.87 per share in 2017 and $.83 per share in 2016)       (690)    
Unrealized foreign currency translation gains (losses) during period, net of income taxes         233  
Unrealized gains (losses) on fixed maturity securities during the period, net of income taxes and reclassification adjustments [1]         1,159  
Unrealized gains (losses) on derivatives during period, net of income taxes         1  
Pension liability adjustment during period, net of income taxes         5  
Purchases of treasury stock           (1,391)
Balance, end of period at Dec. 31, 2017 24,598 135 2,052 29,895 4,028 (11,512)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2016-01 [1]       0 0  
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2018-02 [1]       0 0  
Exercise of stock options     34      
Share-based compensation     54      
Treasury stock reissued     37     40
Net earnings 2,920     2,920    
Dividends to shareholders ($1.04 per share in 2018, $.87 per share in 2017 and $.83 per share in 2016)       (801)    
Unrealized foreign currency translation gains (losses) during period, net of income taxes         228  
Unrealized gains (losses) on fixed maturity securities during the period, net of income taxes and reclassification adjustments [1]         (2,316)  
Unrealized gains (losses) on derivatives during period, net of income taxes         2  
Pension liability adjustment during period, net of income taxes         (17)  
Purchases of treasury stock           (1,317)
Balance, end of period at Dec. 31, 2018 $ 23,462 $ 135 $ 2,177 31,788 2,151 $ (12,789)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2016-01 [1]       148 (148)  
Cumulative effect of change in accounting principle, net of income taxes | Accounting Standards Update 2018-02 [1]       $ (374) $ 374  
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018.
v3.10.0.1
Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Retained earnings:      
Dividends to shareholders (in dollars per share) $ 1.04 $ 0.87 $ 0.83
v3.10.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Cash flows from operating activities:      
Net earnings $ 2,920 $ 4,604 $ 2,659
Adjustments to reconcile net earnings to net cash provided by operating activities:      
Change in receivables and advance premiums (55) (91) 42
Capitalization of deferred policy acquisition costs (1,504) (1,468) (1,447)
Amortization of deferred policy acquisition costs 1,245 1,132 1,141
Increase in policy liabilities 2,343 2,890 3,331
Change in income tax liabilities 64 (1,240) (93)
Realized investment (gains) losses 430 151 14
Other, net 571 150 340 [1]
Net cash provided (used) by operating activities 6,014 6,128 5,987
Proceeds from investments sold or matured:      
Available-for-sale fixed maturity securities 7,888 4,680 6,723
Equity securities, FV-NI 429    
Equity securities, available for sale   902 350
Held-to-maturity fixed maturity securities 1,670 2,212 1,399
Other investments - loan receivables 936 303 90
Costs of investments acquired:      
Available for sale fixed maturity securities (9,086) (9,867) (10,890)
Equity securities, FV-NI (440)    
Equity securities, available-for-sale   (446) (1,079)
Other investments - loan receivables (4,848) (2,115) (1,110)
Other investments, excluding loan receivables, net (414) (206) (98)
Settlement of derivatives, net (241) (621) 1,252
Cash received (pledged or returned) as collateral, net 348 (205) (416)
Other, net 176 (68) (76)
Net cash provided (used) by investing activities (3,582) (5,431) (3,855)
Cash flows from financing activities:      
Purchases of treasury stock (1,301) (1,351) (1,422)
Proceeds from borrowings 1,020 1,040 986
Principal payments under debt obligations (550) (1,161) (610)
Dividends paid to shareholders (793) (661) (658)
Change in investment-type contracts, net (31) 35 159
Treasury stock reissued 58 33 46
Other, net (19) 0 (120) [1]
Net cash provided (used) by financing activities (1,616) (2,065) (1,619)
Effect of exchange rate changes on cash and cash equivalents 30 0 (4)
Net change in cash and cash equivalents 846 (1,368) 509
Cash and cash equivalents, beginning of period 3,491 4,859 4,350
Cash and cash equivalents, end of period 4,337 3,491 4,859
Supplemental disclosures of cash flow information:      
Income taxes paid 998 780 1,526
Interest paid 181 196 211
Noncash interest 41 44 57
Impairment losses included in realized investment losses 81    
Impairment losses included in realized investment losses   37 85
Noncash financing activities:      
Capitalized lease obligations 11 12 1
Senior Notes due 2039 and 2040      
Expense on extinguishment of debt     137
Associate stock bonus      
Noncash financing activities:      
Treasury stock issued 7 29 30
Shareholder dividend reinvestment      
Noncash financing activities:      
Treasury stock issued 8 29 27
Share-based compensation grants      
Noncash financing activities:      
Treasury stock issued $ 2 $ 1 $ 4
[1] Operating activities excludes and financing activities includes a cash outflow of $137 in 2016 for the payments associated with the early extinguishment of debt
v3.10.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Description of Business 
Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac) in the United States (Aflac U.S.) and, effective April 1, 2018, through Aflac Life Insurance Japan Ltd. in Japan (Aflac Japan). Prior to April 1, 2018, the Company's insurance business was marketed in Japan as a branch of Aflac. American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. The Company's insurance operations in the United States and Japan service the two markets for the Company's insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 70% of the Company's total revenues in 2018, compared with 70% in 2017 and 71% in 2016. The percentage of the Company's total assets attributable to Aflac Japan was 84% at December 31, 2018, compared with 83% at December 31, 2017.

Basis of Presentation
The Company prepares its financial statements in accordance with U.S. generally accepted accounting principles (U.S. GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards CodificationTM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates based on currently available information when recording transactions resulting from business operations. The most significant items on the Company's balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments and derivatives, deferred policy acquisition costs (DAC), liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, the Company believes the amounts provided are adequate.

The consolidated financial statements include the accounts of the Parent Company, its subsidiaries, and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.

Significant Accounting Policies

Foreign Currency Translation: The functional currency of Aflac Japan is the Japanese yen. The Company translates its yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses, and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. The Company includes in earnings the realized currency exchange gains and losses resulting from foreign currency transactions.

The Parent Company has designated a majority of its yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and from time-to-time may designate certain foreign currency forwards and options as derivative hedges of the foreign currency exposure of the Company's net investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.

Insurance Revenue and Expense Recognition: Substantially all of the supplemental health and life insurance policies the Company issues are classified as long-duration contracts. The contract provisions generally cannot be
changed or canceled during the contract period; however, the Company may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities.

Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs.

Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method.

At the policyholder's option, customers can also pay discounted advanced premiums for certain of the Company's products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period.

The calculation of DAC and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, the Company reviews its actuarial assumptions and deferrable acquisition costs each year and revises them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, the Company evaluates DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. The Company has not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K.

Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.

Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments, and other debt instruments with a maturity of 90 days or less when purchased.

Investments: The Company's debt securities consist of fixed maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that the Company has the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed maturity debt securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income.

Amortized cost of debt securities is based on the Company's purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt securities the Company purchases at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount.

The Company has investments in equity securities which are carried at fair value. Effective January 1, 2018 upon the adoption of new accounting guidance, changes in fair value of equity securities are recorded in earnings as a component of realized investment gains and losses. Prior to January 1, 2018, equity securities were carried at fair value with unrealized gains and losses, less related deferred income taxes, recorded in other comprehensive income and included in accumulated other comprehensive income.

The Company has investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. The Company is the primary beneficiary of certain VIEs, and therefore consolidates these entities in its financial statements. While the consolidated VIEs generally operate within a defined set of contractual
terms, there are certain powers that are retained by the Company that are considered significant in the conclusion that the Company is the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral; the ability to obtain the underlying collateral in the event of default; and, the ability to appoint or dismiss key parties in the structure. In particular, the Company's powers surrounding the underlying collateral were considered to be the most significant powers because those most significantly impact the economics of the VIE. The Company has no obligation to provide any continuing financial support to any of the entities in which it is the primary beneficiary. The Company's maximum loss is limited to its original investment. Neither the Company nor any of its creditors have the ability to obtain the underlying collateral, nor does the Company have control over the instruments held in the VIEs, unless there is an event of default. For those entities where the Company is the primary beneficiary, the consolidated entity's assets are segregated on the balance sheet by the caption "consolidated variable interest entities," and consist of fixed maturity securities, equity securities, loan receivables, limited partnerships and derivative instruments.

For the mortgage- and asset-backed securities held in the Company's fixed maturity portfolio, the Company recognizes income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income.

The Company uses the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction.

An investment in a fixed maturity security is impaired if the fair value falls below amortized cost. The Company regularly reviews its fixed maturity security investments portfolio for declines in fair value. The Company's fixed maturity security investments are evaluated for other-than-temporary impairment using its debt impairment model. The Company's debt impairment model focuses on the ultimate collection of the cash flows from its investments and whether the Company has the intent to sell or if it is more likely than not the Company would be required to sell the security prior to recovery of its amortized cost. The determination of the amount of impairments under this model is based upon the Company's periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available.
When determining the Company's intention to sell a security prior to recovery of its fair value to amortized cost, the Company evaluates facts and circumstances such as, but not limited to, future cash flow needs, decisions to reposition its security portfolio, and risk profile of individual investment holdings. The Company performs ongoing analyses of its liquidity needs, which includes cash flow testing of its policy liabilities, debt maturities, projected dividend payments, and other cash flow and liquidity needs.

The determination of whether an impairment in value of the Company's fixed maturity securities is other than temporary is based largely on the Company's evaluation of the issuer's creditworthiness. The Company must apply considerable judgment in determining the likelihood of its fixed maturity securities recovering in value. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk and foreign currency risk.

If, after monitoring and analyses, management believes that fair value will not recover to amortized cost, the Company recognizes an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. The Company recognizes a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event the Company intends to sell the security prior to the recovery of its amortized cost or if it is more likely than not that the Company would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income.

The Company lends fixed maturity and public equity securities to financial institutions in short-term security-lending transactions. These securities continue to be carried as investment assets on the Company's balance sheet during the terms of the loans and are not reported as sales. The Company receives cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. For loans where the Company receives as collateral securities that the Company is not permitted to sell or repledge, the collateral is not reported as an asset.

Other investments include transitional real estate loans (TREs), commercial mortgage loans (CMLs), middle market loans (MMLs), policy loans, limited partnerships, and short-term investments with maturities at the time of purchase of one year or less, but greater than 90 days. The Company's investments in TREs, CMLs, and MMLs are accounted for as loan receivables and are recorded at amortized cost on the acquisition date. The Company has the intent and ability to hold these loan receivables for the foreseeable future or until they mature and therefore, they are considered held for investment and are carried at amortized cost in the other investments line in its consolidated balance sheets. The amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date. Limited partnership investments are accounted for using the equity method of accounting. Under the equity method of accounting, the Company reports its portion of partnership earnings as a component of net investment income in its consolidated statements of earnings. The underlying investments held by the Company’s limited partnerships primarily consist of private equity and real estate. Short-term investments are stated at amortized cost, which approximates fair value.

Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are foreign currency forwards, foreign currency options, foreign currency swaps, interest rate swaps, interest rate swaptions, and, in prior year periods, credit default swaps (CDSs). Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated investments in Aflac Japan's portfolio. Foreign currency forwards and options are also used to economically hedge certain portions of forecasted cash flows denominated in yen and hedge the Company's long term exposure to a weakening yen. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Foreign currency swaps are used within special-purpose entities, including VIEs where the Company is the primary beneficiary, to hedge the risk arising from interest rate and currency exchange risk. Interest rate swaps are used to economically hedge interest rate fluctuations in certain variable-rate investments. Interest rate swaptions, which are options to enter into interest rate swaps, are used to hedge interest rate fluctuations on certain U.S. dollar-denominated available-for-sale securities in Aflac Japan's portfolio. The Company does not use derivatives for trading purposes, nor does the Company engage in leveraged derivative transactions.

From time to time, the Company purchases certain investments that contain an embedded derivative. The Company assesses whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If the Company deems that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value, and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If the Company has elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings.
See Note 5 for a discussion on how the Company determines the fair value of its derivatives. Accruals on derivatives are typically recorded in accrued investment income or within other liabilities in the consolidated balance sheets.

To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk attributable to the hedged item. At the inception of hedging relationships the Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objectives and strategies for undertaking the respective hedging relationship, and the methodology that will be used to assess the effectiveness of the hedge relationship at and subsequent to hedge inception. The Company documents the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation. The documentation process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or groups of assets or liabilities in the statement of financial position or to specific forecasted transactions and defining the effectiveness testing methods to be used. At the hedge inception and on an ongoing quarterly basis, the Company also formally assesses whether the derivatives and non-derivative financial instruments used in hedging activities have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. The assessment of hedge effectiveness determines the accounting treatment of changes in fair value.
For assessing hedge effectiveness, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression, dollar offset, or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship. For derivative instruments that are designated and
qualify as cash flow hedges, the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. In cash flow hedges, all components of each derivative's gain or loss are included in the assessment of hedge effectiveness and are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded.
For derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the hedged item and the portion of the hedging instrument included in the assessment of effectiveness are recorded in the line item of the consolidated statements of earnings in which gain or loss on the hedged item is recorded. When assessing the effectiveness of the Company's fair value hedges, the Company excludes the changes in fair value related to the difference between the spot and the forward rate on its foreign currency forwards and the time value of foreign exchange options and interest rate swaptions.
For hedges of the Company's net investment in Aflac Japan, the Company has designated the majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedging instruments and from time to time may designate certain foreign currency forwards and options as derivative hedging instruments. The Company makes its net investment hedge designation at the beginning of each quarter. For assessing hedge effectiveness of net investment hedges, if the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than its net investment in Aflac Japan, the hedge is deemed to be effective. If the hedge is effective, the related exchange effect on the yen-denominated liabilities is reported in the unrealized foreign currency component of other comprehensive income. For derivative hedging instruments designated as net investment hedges, Aflac follows the forward-rate method. According to that method, all changes in fair value, including changes related to the forward-rate component of foreign currency forward contracts and the time value of foreign currency options, are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed the Company's net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds its investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses).
The Company discontinues hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised.
When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item.
If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within derivative and other gains (losses), which is a component of realized investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings.

The Company receives and pledges cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. The Company generally can repledge or resell collateral obtained from counterparties, although the Company does not typically exercise such rights. Securities received as collateral are not recognized unless the Company was to exercise its right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that the Company has pledged as collateral continue to be carried as investment assets on its balance sheet.

Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition.

For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed.
For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), and ordinary life becomes reduced paid-up and certain reinstatements.
An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with the Company's accounting policies for deferred acquisition costs. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions to higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain other contract conversions.
Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered an expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage.
The Company measures the recoverability of DAC and the adequacy of its policy reserves annually by performing gross premium valuations on its business. (See the following discussion for further information regarding policy reserves.)
Policy Liabilities: Future policy benefits represent claims that are expected to occur in the future and are computed following a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect the Company's experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing.
Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. The Company regularly adjusts these estimates as new claims experience emerges and reflects the changes in operating results in the year such adjustments are made.

Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period.

For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract; however, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized.

Reinsurance: The Company enters into reinsurance agreements with other companies in the normal course of business. For each reinsurance agreement, the Company determines if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded.

Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing the Company's income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and
liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which the Company expects the temporary differences to reverse. The Company records deferred tax assets for tax positions taken based on its assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized.

Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. The Company recognizes a charge for its estimated share of the industry's obligation once it is determinable. The Company reviews the estimated liability for policyholder protection corporation contributions on an annual basis and reports any adjustments in Aflac Japan's expenses.

In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. See Note 15 of the Notes to the Consolidated Financial Statements for further discussion of the guaranty fund assessments charged to the Company.

Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. The Company uses the weighted-average purchase cost to determine the cost of treasury stock that is reissued. The Company includes any gains and losses in additional paid-in capital when treasury stock is reissued.

Share-Based Compensation: The Company measures compensation cost related to its share-based payment transactions at fair value on the grant date, and the Company recognizes those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. The Company has formalized its entity-wide accounting policy election to estimate the number of awards that are expected to vest and the corresponding forfeitures.

Earnings Per Share: The Company computes basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.

Stock Split: On February 13, 2018, the Board of Directors of the Parent Company declared a two-for-one stock split of the Company’s common stock in the form of a 100% stock dividend payable on March 16, 2018 to shareholders of record at the close of business on March 2, 2018. The stock split was payable in the form of one additional common stock share for every share of common stock held. All equity and share-based data, including the number of shares outstanding and per share amounts, have been adjusted to reflect the stock split for all periods presented in this Annual Report on Form 10-K.

Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.

Perpetual securities have been reclassified in prior periods from a separate line item to fixed maturity securities to conform to current period reporting classifications. This reclassification had no impact on net earnings or total shareholder’s equity.

New Accounting Pronouncements

Recently Adopted Accounting Pronouncements
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
Accounting Standard Update (ASU) 2018-16 Derivatives and Hedging Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes
In October 2018, the FASB issued amendments to permit use of the Overnight Index Swap (OIS) rate based on the Secured Overnight Financing Rate (SOFR) as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to the Treasury obligations of the U.S. government (UST), the London Interbank Offered Rate (LIBOR) swap rate, the OIS rate based on the Fed Funds Effective Rate, and the Securities Industry and Financial Markets Association (SIFMA) Municipal Swap Rate.
Early adopted as of October 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations or disclosures.
ASU 2018-03
Technical Corrections and Improvements to Financial Instruments - Overall Recognition and Measurement of Financial Assets and Financial Liabilities
In February 2018, the FASB issued amendments to clarify certain aspects of the guidance issued in the original Financial Instruments - Overall - Recognition and Measurement pronouncement summarized below. Specifically, for entities who have chosen the measurement alternative approach for equity securities without readily determinable fair values, the amendments clarify that entities may change from a measurement alternative approach to a fair value method through an irrevocable election that would apply to a specific equity security and all identical or similar investments of the same issuer; entities should use an observable price at the date of the transaction rather than reporting date for the measurement alternative calculation; and insurance companies should use a prospective transition method when applying the measurement alternative.
Early adopted as of January 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations, or disclosures.
ASU 2018-02 
Income Statement - Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income
In February 2018, the FASB issued amendments which allow a reclassification from accumulated other comprehensive income (AOCI) to retained earnings of the effects of the change in the U.S. federal income tax rate resulting from the Tax Cuts and Jobs Act (Tax Act) on the gross deferred tax amounts and the corresponding valuation allowances related to items remaining in AOCI. The amendments eliminate the stranded tax effects resulting from the Tax Act and also require certain disclosures about the reclassified tax effects.
Early adopted as of January 1, 2018
The amounts reclassified from
AOCI to retained earnings include the income tax effects of the change in the federal corporate tax rate enacted by the Tax Act. The Company’s policy is to follow the portfolio approach for releasing income tax effects from AOCI. The adoption of this guidance resulted in an increase to beginning 2018 AOCI of $374 million with a corresponding decrease to beginning 2018 retained earnings as of January 1, 2018.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2017-12
Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities
In August 2017, the FASB issued guidance which improves and simplifies the accounting rules around hedge accounting and creates more transparency around how economic results are presented in financial statements. Issues addressed in this new guidance include: 1) risk component hedging, 2) accounting for the hedged item in fair value hedges of interest rate risk, 3) recognition and presentation of the effects of hedging instruments, and 4) amounts excluded from the assessment of hedge effectiveness.
Early adopted as of October 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-09 Compensation - Stock Compensation: Scope of Modification Accounting
In May 2017, the FASB issued amendments to provide guidance clarifying when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. An entity should apply modification accounting if the fair value, vesting conditions or classification of the award (as an equity instrument or liability instrument) changes as a result of the change in terms or conditions of the award.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-08 
Receivables - Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities

In March 2017, the FASB issued amendments to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount.
Early adopted as of July 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2017-07 
Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost
In March 2017, the FASB issued amendments requiring that an employer report the service cost component of net periodic pension cost and net periodic postretirement benefit cost in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net periodic pension cost and net periodic postretirement benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. The amendments in this update also allow only the service cost component to be eligible for capitalization when applicable.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2017-05
Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets: Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets
In February 2017, the FASB issued amendments that clarify the scope and accounting guidance for the derecognition of a nonfinancial asset or a financial asset that meets the definition of an "in substance nonfinancial asset." The amendments define an "in substance nonfinancial asset" and provide additional accounting guidance for partial sales of nonfinancial assets.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-01
Business Combinations: Clarifying the Definition of a Business
In January 2017, the FASB issued amendments clarifying when a set of assets and activities is a business. The amendments provide a screen to exclude transactions where substantially all the fair value of the transferred set is concentrated in a single asset, or group of similar assets, from being evaluated as a business.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-18 
Statement of Cash Flows: Restricted Cash
In November 2016, the FASB issued amendments requiring that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, statements of cash flows, or disclosures.
ASU 2016-17
Consolidation - Interests Held through Related Parties That Are under Common Control
In October 2016, the FASB issued amendments which clarify the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (VIE) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-16 
Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory
In October 2016, the FASB issued amendments that require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-15 Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments
In August 2016, the FASB issued amendments that provide guidance on eight specific statement of cash flow classification issues, including distributions received from equity method investees.
January 1, 2018
The Company elected nature of distribution for distributions received from equity method investees. The adoption of this guidance did not have a significant impact on the Company's financial position, statement of cash flows, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2016-09
Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting

In March 2016, the FASB issued amendments which simplify several aspects for share-based payment award transactions, including the income tax consequences, classification of awards as either liability or equity, classification of taxes paid on the statement of cash flows and treatment of forfeitures.


January 1, 2017
As a result of applying this requirement, the Company believes that recognition of excess tax benefits will increase volatility in its statement of operations and the Company made an entity-wide accounting policy election to estimate the number of awards that are expected to vest (consistent with the Company's prior policy), but the adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, statements of cash flows, or disclosures.
ASU 2016-07
Investments - Equity Method and Joint Ventures - Simplifying the Transition to the Equity Method of
Accounting
In March 2016, the FASB issued amendments which eliminate the requirement that when an investment
qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. Per the amendments, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-06
Derivatives and Hedging - Contingent Put and Call Options in Debt Instruments
In March 2016, the FASB issued amendments which clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. Consequently, when a call (put) option is contingently exercisable, an entity does not have to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-05
Derivatives and Hedging - Effect of Derivative Contract Novations on Existing Hedge Accounting
Relationships
In March 2016, the FASB issued amendments which clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria remain intact.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2016-01 
Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities
In January 2016, the FASB issued guidance to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The main provisions of this guidance require certain equity investments to be measured at fair value with changes in fair value recognized in net earnings; separate presentation in other comprehensive income for changes in fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk; and changes in disclosures associated with the fair value of financial instruments. The guidance also clarifies that entities should evaluate the need for a valuation allowance on a deferred tax asset (DTA) related to available-for-sale (AFS) securities in combination with the entity's other DTAs.
January 1, 2018
The Company recorded a cumulative effect adjustment with an increase to beginning 2018 retained earnings and a decrease to beginning 2018 AOCI of $148 million, net of taxes.
ASU 2015-16
Business Combinations - Simplifying the Accounting for Measurement-Period Adjustments
In September 2015, the FASB issued guidance requiring that an acquirer recognize adjustments to estimated amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. In the same period’s financial statements, the acquirer is required to record income effects of the adjustments as if the accounting had been completed at the acquisition date. The acquirer is also required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the estimated amounts had been recognized as of the acquisition date.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2015-09
Financial Services - Insurance - Disclosures about Short-Duration Contracts
In May 2015, the FASB issued updated guidance requiring enhanced disclosures by all insurance entities that issue short-duration contracts. The amendments require insurance entities to disclose for annual reporting periods information about the liability for unpaid claims and claim adjustment expenses. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses. In addition, the amendments require insurance entities to disclose for annual and interim reporting periods a roll-forward of the liability for unpaid claims and claim adjustment expenses. For health insurance claims, the amendments require the disclosure of the total of incurred-but-not-reported liabilities and expected development on reported claims included in the liability for unpaid claims and claim adjustment expenses.
December 31, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2015-07
Fair Value Measurement - Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)
In May 2015, the FASB issued updated guidance that removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendments also remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. Rather, those disclosures are limited to investments for which the entity has elected to measure the fair value using that practical expedient.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2015-03
Interest - Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs
In April 2015, the FASB issued updated guidance to simplify presentation of debt issuance costs. The updated guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. In August 2015, the FASB issued updated Securities and Exchange Commission (SEC) Staff guidance pertaining to the presentation of debt issuance costs related to line-of-credit arrangements. The guidance states that an entity may defer and present debt issuance costs as an asset, subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement.
January 1, 2016
The retrospective adoption of this accounting standard resulted in a $40 million reduction to notes payable and other assets as of December 31, 2015, the earliest balance sheet date presented in the period of adoption, but did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2015-02
Consolidation - Amendments to the Consolidation Analysis
In February 2015, the FASB issued updated guidance that affects evaluation of whether limited partnerships and similar legal entities (limited liability corporations and securitization structures, etc.) are VIEs, evaluation of whether fees paid to a decision maker or a service provider are a variable interest, and evaluation of the effect of fee arrangements and the effect of related parties on the determination of the primary beneficiary under the VIE model for consolidation. The updated guidance eliminates the presumption that a general partner should consolidate a limited partnership. Limited partnership and similar legal entities that provide partners with either substantive kick-out rights or substantive participating rights over the general partner will now be evaluated under the voting interest model rather than the VIE model for consolidation. In situations where no single party has a controlling financial interest in a VIE, the related party relationships under common control should be considered in their entirety in determining whether that common control group has a controlling financial interest in the VIE.
January 1, 2016
The adoption of this guidance impacted the Company's footnote disclosures, but did not have a significant impact on its financial position or results of operations.

ASU 2014-16
Derivatives and Hedging - Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity
In November 2014, the FASB issued guidance to clarify how to evaluate the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The guidance also clarifies that an entity should assess the substance of the relevant terms and features when considering how to weight those terms and features.
January 1, 2016
The adoption of this guidance impacted the Company's footnote disclosures, but did not have a significant impact on its financial position or results of operations.

ASU 2014-15
Presentation of Financial Statements - Going Concern - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern
In August 2014, the FASB issued this amendment that provides U.S. GAAP guidance on management’s responsibility in evaluating whether there is substantial doubt about a company’s ability to continue as a going concern and about related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. The new guidance requires a formal assessment of going concern by management based on criteria prescribed in the new guidance.
December 31, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations or disclosures and no substantial doubt currently exists about the Company's ability to continue as a going concern.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2014-12
Compensation - Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period
In June 2014, the FASB issued this amendment that provides guidance on certain share-based payment awards that require a specific performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2014-09
Revenue from Contracts with Customers
In May 2014, the FASB issued updated guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.

Accounting Pronouncements Pending Adoption
Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-20 Leases: Narrow-Scope Improvements for Lessors
In December 2018, the FASB issued narrow-scope improvements for lessors which 1) provide an accounting policy election for lessors to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price; 2) require lessors to exclude the costs from variable lease revenue and the associated expense when the amount of those costs is not readily determinable by the lessor; and 3) require lessors to allocate (rather than recognize) certain variable payments to the lease and nonlease components when the changes in facts and circumstances on which the variable payment is based occur. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted.
The Company has made an accounting policy election to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price. The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-17 Consolidation: Targeted Improvements to Related Party Guidance for Variable Interest Entities
In October 2018, the FASB issued targeted improvements which provide that indirect interests held through related parties under common control should be considered on a proportional basis for determining whether fees paid to decision makers and service providers are variable interests. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations or disclosures.
ASU 2018-15
Intangibles - Goodwill and Other - Internal-Use Software, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract
In August 2018, the FASB issued amendments to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted.

The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations or disclosures.

ASU 2018-14
Compensation - Retirement Benefits - Defined Benefit Plans - General, Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans
In August 2018, the FASB issued amendments to modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. Accordingly, six disclosure requirements were removed, two added and two clarified. The amendments are effective for public business entities for fiscal years beginning after December 15, 2020. Early adoption is permitted.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-13
Fair Value Measurement, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement
In August 2018, the FASB issued amendments to the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The amendments remove, modify, and add certain disclosures. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted upon issuance of this Update. An entity is permitted to early adopt any removed or modified disclosures upon issuance of this update and delay adoption of the additional disclosures until their effective date.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-12
Financial Services - Insurance, Targeted Improvements to the Accounting for Long-Duration Contracts

In August 2018, the FASB issued amendments that will significantly change how insurers account for long-duration contracts. The amendments will change existing recognition, measurement, presentation, and disclosure requirements. Issues addressed in the new guidance include: 1) a requirement to review and, if there is a change, update assumptions for the liability for future policy benefits at least annually, and to update the discount rate assumption quarterly, 2) accounting for market risk benefits at fair value, 3) simplified amortization for deferred acquisition costs, and 4) enhanced financial statement presentation and disclosures. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early application of the amendments is permitted.

The Company is thoroughly evaluating the impact of adoption and expects that the adoption will have a significant impact on the Company’s financial position, results of operations, and disclosures. The Company anticipates that the requirement to update assumptions for liability for future policy benefits will have a significant impact on its results of operations, systems, processes and controls while the requirement to update the discount rate will have a significant impact on its equity. The Company does not expect to early adopt the updated standard.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-11
Leases, Targeted Improvements

In July 2018, the FASB issued targeted improvements to Topic 842 Leases. The amendments in the update provide entities with an optional transition method to adopt the new leases standard by recording a cumulative effect adjustment to beginning retained earnings. Additionally, the amendments provide lessors with a practical expedient to not separate nonlease components from associated lease components and instead account for those components as a single component under certain conditions. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted.
The Company has elected the optional transition method. The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-10
Codification Improvements to Topic 842, Leases

In July 2018, the FASB issued guidance which clarifies, corrects errors in, or makes minor improvements to the Codification related to ASU 2016-02, Leases (Topic 842). The amendments in this ASU affect narrow aspects of the guidance issued in the amendments to ASU 2016-02, including but not limited to, Residual Value Guarantees, Rate Implicit in the Lease, Lessee Reassessment of Lease Classification and Variable Lease Payments that Depend on an Index or a Rate. Amendments within this ASU follow the effective dates of Topic 842, which are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years.
The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2018-01
Leases: Land Easement Practical Expedient for Transition to Topic 842
In January 2018, the FASB issued guidance which provides an entity with the option to elect a transition practical expedient to not evaluate, under Topic 842, land easements that exist or expired before the entity's adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. The amendments clarify that new or modified land easements should be evaluated under the new leases standard once an entity has adopted the new standard. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted.
As of December 31, 2018, the Company did not have land easements, but has elected this practical expedient as a safe harbor. The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-04
Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment
In January 2017, the FASB issued amendments simplifying the subsequent measurement of goodwill. An entity is no longer required to perform a hypothetical purchase price allocation to measure goodwill impairment. Instead, the entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. The amendments are effective for public business entities that are SEC filers for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for any goodwill impairment tests performed on testing dates after January 1, 2017.
The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2016-13
Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments
In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured on an amortized cost basis to be presented net of an allowance for credit losses in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform about a credit loss. Credit losses on available-for-sale debt securities will continue to be measured in a manner similar to current U.S. GAAP; however, the amendments require that credit losses be presented as an allowance rather than as a write-down. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant amount of credit deterioration since origination (PCD financial assets). The amendments are effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Companies may early adopt this guidance as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The amendments will be adopted following a modified-retrospective approach resulting in a cumulative effect adjustment in retained earnings as of the beginning of the year of adoption. Two exceptions to this adoption method are for PCD financial assets and debt securities for which other-than-temporary impairment (OTTI) will have been recognized before the effective date. Loans purchased with credit deterioration accounted for under current U.S. GAAP as "purchased credit impaired" (PCI) financial assets will be classified as PCD financial assets at transition and PCD guidance will be applied prospectively. Debt securities that have experienced OTTI before the effective date will follow a prospective adoption method which allows an entity to maintain the same amortized cost basis before and after the effective date.
The Company has identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, loans and loan receivables and reinsurance recoverables (See Notes 3 and 7 for current balances of instruments in scope). The Company is continuing its progress towards updating its credit loss projection models and accounting systems in order to comply with the required changes in measurement of credit losses. The Company currently expects loans and loan receivables and held-to-maturity fixed maturity securities to be the asset classes most significantly impacted upon adoption of the guidance. The Company continues to evaluate the impact of adoption of this guidance on its financial position, results of operations, and disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2016-02
Leases
In February 2016, the FASB issued updated guidance for accounting for leases. Per the amendments, lessees will be required to recognize all leases on the balance sheet with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new standard is effective for the Company on January 1, 2019. A modified retrospective transition approach is required, applying the new standard to all leases existing at the date of initial application. The Company is electing to use its effective date as its date of initial application. Because the Company expects to adopt the new standard on January 1, 2019 and use the effective date as the date of initial application, financial information is not required to be updated and the disclosures required under the new standard are not required to be provided for dates and periods before January 1, 2019. The new standard provides a number of optional practical expedients. The Company has elected the "package of practical expedients," which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Under the new guidance, lessor accounting is largely unchanged. The amendments are effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period.
The Company has identified certain operating leases in scope of this guidance to include office space and equipment leases (See Note 15). The leases within scope of this guidance will increase the Company's right-of-use assets and lease liabilities recorded on its statement of financial position by approximately $100 to $200 million. The Company estimates that the adoption of this guidance will not have a significant impact on its financial position, results of operations, or disclosures.


Recent accounting guidance not discussed above is not applicable, did not have, or is not expected to have a material impact to the Company's business.
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION
 12 Months Ended
Dec. 31, 2018
Segment Reporting [Abstract]  
BUSINESS SEGMENT INFORMATION BUSINESS SEGMENT AND FOREIGN INFORMATION
The Company consists of two reportable insurance business segments: Aflac Japan and Aflac U.S., both of which sell supplemental health and life insurance. Operating business segments that are not individually reportable and business activities, including reinsurance retrocession activities, not included in Aflac Japan or Aflac U.S. are included in the "Corporate and other" category.

The Company does not allocate corporate overhead expenses to business segments. Consistent with U.S. GAAP accounting guidance for segment reporting, the Company evaluates and manages its business segments using a financial performance measure called pretax adjusted earnings. Adjusted earnings are adjusted revenues less benefits and adjusted expenses. The adjustments to both revenues and expenses account for certain items that cannot be predicted or that are outside management’s control. Adjusted revenues are U.S. GAAP total revenues excluding realized investment gains and losses, except for amortized hedge costs related to foreign currency exposure management strategies and net interest cash flows from derivatives associated with certain investment strategies. Adjusted expenses are U.S. GAAP total acquisition and operating expenses including the impact of interest cash flows from derivatives associated with notes payable but excluding any nonrecurring or other items not associated with the normal course of the Company’s insurance operations and that do not reflect Aflac’s underlying business performance. The Company excludes income taxes related to operations to arrive at pretax adjusted earnings. Information regarding operations by segment for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
Revenues:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan:
 
 
 
 
 
 
 
 
 
 
 
   Net earned premiums:
 
 
 
 
 
 
 
 
 
 
 
             Cancer
 
$
5,849

 
 
 
$
5,612

 
 
 
$
5,639

 
             Medical and other health
 
3,516

 
 
 
3,379

 
 
 
3,429

 
             Life insurance
 
3,397

 
 
 
3,761

 
 
 
4,469

 
   Net investment income, less amortized hedge costs
 
2,403

 
 
 
2,235

 
 
 
2,368

 
   Other income
 
41

 
 
 
41

 
 
 
40

 
               Total Aflac Japan
 
15,206

 
 
 
15,028

 
 
 
15,945

 
Aflac U.S.:
 
 
 
 
 
 
 
 
 
 
 
   Net earned premiums:
 
 
 
 
 
 
 
 
 
 
 
             Accident/disability
 
2,611

 
 
 
2,537

 
 
 
2,469

 
             Cancer
 
1,311

 
 
 
1,308

 
 
 
1,299

 
             Other health
 
1,508

 
 
 
1,445

 
 
 
1,415

 
             Life insurance
 
278

 
 
 
273

 
 
 
271

 
   Net investment income
 
727

 
 
 
721

 
 
 
703

 
   Other income
 
8

 
 
 
5

 
 
 
10

 
           Total Aflac U.S.
 
6,443

 
 
 
6,289

 
 
 
6,167

 
Corporate and other
 
339

 
 
 
272

 
 
 
275

 
           Total adjusted revenues
 
21,988

 
 
 
21,589

 
 
 
22,387

 
Realized investment gains (losses) (1),(2),(3)
 
(230
)
 
 
 
78

 
 
 
172

 
           Total revenues
 
$
21,758

 
 
 
$
21,667

 
 
 
$
22,559

 

(1) Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from net investment income when analyzing segment operations.
(2) Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in net investment income when analyzing operations.
(3) An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
(In millions)
2018
 
2017
 
2016
Pretax earnings:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
3,208

 
 
 
$
3,054

 
 
 
$
3,148

 
Aflac U.S.
 
1,285

 
 
 
1,245

 
 
 
1,208

 
Corporate and other
 
(139
)
 
 
 
(212
)
 
 
 
(239
)
 
    Pretax adjusted earnings
 
4,354

 
 
 
4,087

 
 
 
4,117

 
Realized investment gains (losses) (1),(2),(3),(4)
 
(297
)
 
 
 
0

 
 
 
87

 
Other income (loss) (5)
 
(74
)

 
 
(69
)
 
 
 
(137
)

    Total earnings before income taxes
 
$
3,983

 
 
 
$
4,018

 
 
 
$
4,067

 
Income taxes applicable to pretax adjusted earnings
 
$
1,129

 
 
 
$
1,370

 
 
 
$
1,426

 
Effect of foreign currency translation on after-tax
adjusted earnings
 
28

 
 
 
(41
)
 
 
 
141

 

(1) Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from pretax adjusted earnings when analyzing segment operations.
(2) Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in pretax adjusted earnings when analyzing operations.
(3) An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
(4) Excluding a gain of $67 in 2018, $77 in 2017 and $85 in 2016, related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is included in adjusted earnings when analyzing segment operations
(5) Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt

Assets as of December 31 were as follows:
(In millions)
2018
 
2017
 
Assets:
 
 
 
 
 
 
 
 
Aflac Japan
 
$
118,342

 
 
 
$
114,402

 
 
Aflac U.S.
 
19,100

 
 
 
19,893

 
 
Corporate and other
 
2,964

 
 
 
2,922

 
 
    Total assets
 
$
140,406

 
 
 
$
137,217

 
 


Yen-Translation Effects: The following table shows the yen/dollar exchange rates used for or during the periods ended December 31. Exchange effects were calculated using the same yen/dollar exchange rate for the current year as for each respective prior year.
 
2018
 
2017
 
2016
Statements of Earnings:
 
 
 
 
 
 
 
 
 
 
 
Weighted-average yen/dollar exchange rate(1)
 
110.39

 
 
 
112.16

 
 
 
108.70

 
Yen percent strengthening (weakening)
 
1.6
%
 
 
 
(3.1
)%
 
 
 
11.3
%
 
Exchange effect on pretax operating earnings (in millions)
 
$
38

 
 
 
$
(63
)
 
 
 
$
218

 

 
2018
 
2017
Balance Sheets:
 
 
 
 
 
 
 
Yen/dollar exchange rate at December 31(1)
 
111.00

 
 
 
113.00

 
Yen percent strengthening (weakening)
 
1.8
%
 
 
 
3.1
%
 
Exchange effect on total assets (in millions)
 
$
1,362

 
 
 
$
2,593

 
Exchange effect on total liabilities (in millions)
 
1,270

 
 
 
2,848

 

(1) Rates are based on the published MUFG Bank, Ltd. telegraphic transfer middle rate (TTM)

Transfers of funds from Aflac Japan: Aflac Japan makes payments to the Parent Company for management fees, allocated expenses and remittances of earnings. Prior to the Aflac Japan branch conversion on April 1, 2018, Aflac Japan paid allocated expenses and profit remittances to Aflac U.S. Information on transfers for each of the years ended December 31 is shown below. See Note 13 for information concerning restrictions on transfers from Aflac Japan.
(In millions)
2018
 
2017
 
2016
Management fees
 
$
136

 
 
 
$
93

 
 
 
$
79

 
Allocated expenses
 
24

 
 
 
109

 
 
 
106

 
Profit remittances
 
808

 
 
 
1,150

 
 
 
1,286

 
Total transfers from Aflac Japan
 
$
968

 
 
 
$
1,352

 
 
 
$
1,471

 


Property and Equipment: The costs of buildings, furniture and equipment are depreciated principally on a straight-line basis over their estimated useful lives (maximum of 50 years for buildings and 20 years for furniture and equipment). Expenditures for maintenance and repairs are expensed as incurred; expenditures for betterments are capitalized and depreciated. Classes of property and equipment as of December 31 were as follows:
(In millions)
2018
 
2017
Property and equipment:
 
 
 
 
 
 
 
Land
 
$
168

 
 
 
$
168

 
Buildings
 
456

 
 
 
441

 
Equipment and furniture
 
400

 
 
 
372

 
Total property and equipment
 
1,024

 
 
 
981

 
Less accumulated depreciation
 
581

 
 
 
547

 
Net property and equipment
 
$
443

 
 
 
$
434

 


Receivables: Receivables consist primarily of monthly insurance premiums due from individual policyholders or their employers for payroll deduction of premiums, net of an allowance for doubtful accounts. At December 31, 2018, $334 million, or 39.2% of total receivables, were related to Aflac Japan's operations, compared with $334 million, or 40.4%, at December 31, 2017.
v3.10.0.1
INVESTMENTS
 12 Months Ended
Dec. 31, 2018
Investments [Abstract]  
INVESTMENTS INVESTMENTSNet Investment Income

The components of net investment income for the years ended December 31 were as follows:
(In millions)
2018
 
2017
 
2016
Fixed maturity securities
 
$
3,142

 
 
 
$
3,173

 
 
 
$
3,308

 
Equity securities
 
38

 
 
 
42

 
 
 
35

 
Other investments
 
369

 
 
 
94

 
 
 
31

 
Short-term investments and cash equivalents
 
41

 
 
 
25

 
 
 
11

 
Gross investment income
 
3,590

 
 
 
3,334

 
 
 
3,385

 
Less investment expenses
 
148

 
 
 
114

 
 
 
107

 
Net investment income
 
$
3,442

 
 
 
$
3,220

 
 
 
$
3,278

 
Investment Holdings
The amortized cost for the Company's investments in fixed maturity securities, the cost for equity securities and the fair values of these investments at December 31 are shown in the following tables.
  
2018
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
  Fair
  Value
Securities available for sale, carried at fair value
through other comprehensive income:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
30,637

 
 
 
$
3,700

 
 
 
$
140

 
 
 
$
34,197

 
Municipalities
 
385

 
 
 
32

 
 
 
9

 
 
 
408

 
Mortgage- and asset-backed securities
 
155

 
 
 
22

 
 
 
0

 
 
 
177

 
Public utilities
 
1,732

 
 
 
280

 
 
 
4

 
 
 
2,008

 
Sovereign and supranational
 
826

 
 
 
123

 
 
 
0

 
 
 
949

 
Banks/financial institutions
 
5,440

 
 
 
502

 
 
 
238

 
 
 
5,704

 
Other corporate
 
4,852

 
 
 
649

 
 
 
44

 
 
 
5,457

 
Total yen-denominated
 
44,027

 
 
 
5,308

 
 
 
435

 
 
 
48,900

 
  U.S. dollar-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government and agencies
 
137

 
 
 
9

 
 
 
1

 
 
 
145

 
Municipalities
 
1,343

 
 
 
120

 
 
 
8

 
 
 
1,455

 
Mortgage- and asset-backed securities
 
155

 
 
 
8

 
 
 
1

 
 
 
162

 
Public utilities
 
4,772

 
 
 
496

 
 
 
105

 
 
 
5,163

 
Sovereign and supranational
 
251

 
 
 
60

 
 
 
0

 
 
 
311

 
Banks/financial institutions
 
2,860

 
 
 
389

 
 
 
35

 
 
 
3,214

 
Other corporate
 
23,311

 
 
 
1,343

 
 
 
1,109

 
 
 
23,545

 
Total U.S. dollar-denominated
 
32,829

 
 
 
2,425

 
 
 
1,259

 
 
 
33,995

 
Total securities available for sale
 
$
76,856

(1) 
 
 
$
7,733

 
 
 
$
1,694

 
 
 
$
82,895

(1) 

(1) Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)

  
2018
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair  
Value  
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
21,712

 
 
 
$
5,326

 
 
 
$
0

 
 
 
$
27,038

 
Municipalities
 
359

 
 
 
110

 
 
 
0

 
 
 
469

 
Mortgage- and asset-backed securities
 
14

 
 
 
1

 
 
 
0

 
 
 
15

 
Public utilities
 
2,727

 
 
 
254

 
 
 
8

 
 
 
2,973

 
Sovereign and supranational
 
1,551

 
 
 
289

 
 
 
0

 
 
 
1,840

 
Banks/financial institutions
 
1,445

 
 
 
158

 
 
 
20

 
 
 
1,583

 
Other corporate
 
2,510

 
 
 
332

 
 
 
38

 
 
 
2,804

 
Total yen-denominated
 
30,318

 
 
 
6,470

 
 
 
66

 
 
 
36,722

 
Total securities held to maturity
 
$
30,318

 
 
 
$
6,470

 
 
 
$
66

 
 
 
$
36,722

 


  
2018
(In millions)
 
 
 
 
 
 
Fair  
Value  
Equity securities, carried at fair value through
net earnings:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Equity securities: (1) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Yen-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
$
641

 
      U.S. dollar-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
346

 
Total equity securities
 
 
 
 
 
 
 
 
 
 
 
 
 
$
987

(1) 
(1) Includes perpetual securities ($62 at fair value)
 
 
2017
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
  Fair
  Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
27,980

 
 
 
$
3,363

 
 
 
$
271

 
 
 
$
31,072

 
Municipalities
 
314

 
 
 
28

 
 
 
12

 
 
 
330

 
Mortgage- and asset-backed securities
 
242

 
 
 
29

 
 
 
0

 
 
 
271

 
Public utilities
 
1,635

 
 
 
352

 
 
 
6

 
 
 
1,981

 
Sovereign and supranational
 
1,380

 
 
 
190

 
 
 
1

 
 
 
1,569

 
Banks/financial institutions
 
4,742

 
 
 
811

 
 
 
53

 
 
 
5,500

 
Other corporate
 
4,085

 
 
 
809

 
 
 
7

 
 
 
4,887

 
Total yen-denominated
 
40,378

 
 
 
5,582

 
 
 
350

 
 
 
45,610

 
  U.S dollar-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government and agencies
 
146

 
 
 
13

 
 
 
1

 
 
 
158

 
Municipalities
 
872

 
 
 
168

 
 
 
0

 
 
 
1,040

 
Mortgage- and asset-backed securities
 
161

 
 
 
12

 
 
 
0

 
 
 
173

 
Public utilities
 
5,116

 
 
 
884

 
 
 
27

 
 
 
5,973

 
Sovereign and supranational
 
267

 
 
 
73

 
 
 
0

 
 
 
340

 
Banks/financial institutions
 
2,808

 
 
 
633

 
 
 
8

 
 
 
3,433

 
Other corporate
 
25,384

 
 
 
2,620

 
 
 
418

 
 
 
27,586

 
Total U.S. dollar-denominated
 
34,754

 
 
 
4,403

 
 
 
454

 
 
 
38,703

 
Total securities available for sale
 
$
75,132

(1) 
 
 
$
9,985

 
 
 
$
804

 
 
 
$
84,313

(1) 

(1) Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)


  
2017
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
21,331

 
 
 
$
5,160

 
 
 
$
0

 
 
 
$
26,491

 
Municipalities
 
357

 
 
 
105

 
 
 
0

 
 
 
462

 
Mortgage- and asset-backed securities
 
26

 
 
 
1

 
 
 
0

 
 
 
27

 
Public utilities
 
3,300

 
 
 
398

 
 
 
0

 
 
 
3,698

 
Sovereign and supranational
 
1,523

 
 
 
312

 
 
 
0

 
 
 
1,835

 
Banks/financial institutions
 
2,206

 
 
 
190

 
 
 
9

 
 
 
2,387

 
Other corporate
 
2,687

 
 
 
485

 
 
 
0

 
 
 
3,172

 
Total yen-denominated
 
31,430

 
 
 
6,651

 
 
 
9

 
 
 
38,072

 
Total securities held to maturity
 
$
31,430

 
 
 
$
6,651

 
 
 
$
9

 
 
 
$
38,072

 


  
2017
(In millions)
 
 
 
 
 
 
Fair
Value
Equity securities, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Equity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Yen-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
$
695

 
      U.S. dollar-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
328

 
Total equity securities
 
 
 
 
 
 
 
 
 
 
 
 
 
$
1,023

 


The methods of determining the fair values of the Company's investments in fixed maturity securities and equity securities are described in Note 5.

During 2018, the Company did not reclassify any investments from the held-to-maturity category to the available-for-sale category. During 2017, the Company reclassified three investments from the held-to-maturity category to the available-for-sale category as a result of the issuers' credit rating being downgraded to below investment grade. At the time of the transfer, the securities had an aggregate amortized cost of $773 million and an aggregate unrealized gain of $47 million. During 2016, the Company did not reclassify any investments from the held-to-maturity category to the available-for-sale category.Contractual and Economic Maturities

The contractual maturities of the Company's investments in fixed maturity securities at December 31, 2018, were as follows:
(In millions)
Amortized
Cost
 
Fair
Value
Available for sale: (1)
 
 
 
 
 
 
Due in one year or less
 
$
810

 
 
 
$
861

Due after one year through five years
 
8,313

 
 
 
8,312

Due after five years through 10 years
 
9,805

 
 
 
10,355

Due after 10 years
 
57,618

 
 
 
63,028

Mortgage- and asset-backed securities
 
310

 
 
 
339

Total fixed maturity securities available for sale
 
$
76,856

 
 
 
$
82,895

Held to maturity:
 
 
 
 
 
 
Due in one year or less
 
$
180

 
 
 
$
182

Due after one year through five years
 
915

 
 
 
948

Due after five years through 10 years
 
927

 
 
 
1,004

Due after 10 years
 
28,282

 
 
 
34,573

Mortgage- and asset-backed securities
 
14

 
 
 
15

Total fixed maturity securities held to maturity
 
$
30,318

 
 
 
$
36,722


(1) Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)

Expected maturities may differ from contractual maturities because some issuers have the right to call or prepay obligations with or without call or prepayment penalties.Investment exposures that individually exceeded 10% of shareholders' equity as of December 31 were as follows:
 
2018
 
2017
(In millions)
Credit
Rating
 
Amortized
Cost
 
Fair
Value
 
Credit
Rating
 
Amortized
Cost
 
Fair
Value
Japan National Government(1)
A+
 
$51,207
 
$59,945
 
A
 
$48,399
 
$56,532
(1)Japan Government Bonds (JGBs) or JGB-backed securitiesRealized Investment Gains and Losses

Information regarding pretax realized gains and losses from investments for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
 
Realized investment gains (losses):
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
Available for sale:
 
 
 
 
 
 
Gross gains from sales
$
101

 
$
51

 
$
177

 
Gross losses from sales
(156
)
 
(68
)
 
(62
)
 
Foreign currency gains (losses) on sales and redemptions
73

 
(48
)
 
4

 
Other-than-temporary impairment losses
(64
)
 
(7
)
 
(26
)
 
Total fixed maturity securities
(46
)
 
(72
)
 
93

 
Equity securities (1),(2)
(131
)
 
71

(3) 
(35
)
(3) 
Loan receivables:
 
 
 
 
 
 
Loan loss reserves
(17
)
 
(8
)
 
(2
)
 
Other gains (losses) on loans
(2
)
 
0

 
0

 
Total loan receivables
(19
)
 
(8
)
 
(2
)
 
Derivatives and other:
 
 
 
 
 
 
Derivative gains (losses)
(224
)
 
(109
)
 
(255
)
 
Foreign currency gains (losses)
(10
)
 
(33
)
 
185

 
Total derivatives and other
(234
)
 
(142
)
 
(70
)
 
Total realized investment gains (losses)
$
(430
)
 
$
(151
)
 
$
(14
)
 

(1) Includes perpetual securities
(2) See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
(3) Includes impairments of $22 in 2017 and $57 in 2016

The unrealized holding losses, net of gains, recorded as a component of realized investment gains and losses for the year ended December 31, 2018, that relates to equity securities still held at the December 31, 2018, reporting date was $124 million.Unrealized Investment Gains and Losses

Information regarding changes in unrealized gains and losses from investments recorded in AOCI for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
Changes in unrealized gains (losses):
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
(3,142
)
 
 
 
$
1,657

 
 
 
$
2,711

 
Equity securities (2)
 
0

 
 
 
71

 
 
 
88

 
Total change in unrealized gains (losses)
 
$
(3,142
)
 
 
 
$
1,728

 
 
 
$
2,799

 

(1) Includes perpetual securities
(2) See Note 1 and Note 11 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance and the cumulative effect of the change in accounting principle related to financial instruments effective January 1, 2018.

Effect on Shareholders' Equity

The net effect on shareholders' equity of unrealized gains and losses from investment securities at December 31 was as follows:
(In millions)
2018
 
2017
Unrealized gains (losses) on securities available for sale
 
$
6,039

 
 
 
$
9,358

 
Deferred income taxes
 
(1,805
)
 
 
 
(3,394
)
 
Shareholders’ equity, unrealized gains (losses) on investment securities
 
$
4,234

 
 
 
$
5,964

 

See Notes 1 and 10 for discussion of the accounting treatment of tax on amounts recorded in accumulated other comprehensive income pursuant to the Tax Act and Note 1 for the adoption of accounting guidance on January 1, 2018 related to financial instruments.

Gross Unrealized Loss Aging

The following tables show the fair values and gross unrealized losses of the Company's available-for-sale and held-to-maturity investments that were in an unrealized loss position, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31.
 
  
2018
  
Total
 
Less than 12 months
 
12 months or longer
(In millions)
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
$
67

 
 
 
$
1

 
 
 
$
67

 
 
 
$
1

 
 
 
$
0

 
 
 
$
0

 
  Japan government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
3,604

 
 
 
140

 
 
 
3,604

 
 
 
140

 
 
 
0

 
 
 
0

 
  Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
515

 
 
 
8

 
 
 
515

 
 
 
8

 
 
 
0

 
 
 
0

 
  Yen-denominated
 
148

 
 
 
9

 
 
 
148

 
 
 
9

 
 
 
0

 
 
 
0

 
Mortgage- and asset-
backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
74

 
 
 
1

 
 
 
74

 
 
 
1

 
 
 
0

 
 
 
0

 
  Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
1,585

 
 
 
105

 
 
 
892

 
 
 
48

 
 
 
693

 
 
 
57

 
  Yen-denominated
 
604

 
 
 
12

 
 
 
604

 
 
 
12

 
 
 
0

 
 
 
0

 
  Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
625

 
 
 
35

 
 
 
340

 
 
 
19

 
 
 
285

 
 
 
16

 
  Yen-denominated
 
3,057

 
 
 
258

 
 
 
3,057

 
 
 
258

 
 
 
0

 
 
 
0

 
  Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
12,899

 
 
 
1,109

 
 
 
5,782

 
 
 
407

 
 
 
7,117

 
 
 
702

 
  Yen-denominated
 
1,306

 
 
 
82

 
 
 
1,306

 
 
 
82

 
 
 
0

 
 
 
0

 
  Total
 
$
24,484

 
 
 
$
1,760

 
 
 
$
16,389

 
 
 
$
985

 
 
 
$
8,095

 
 
 
$
775

 

(1) Includes perpetual securities



  
2017
  
Total
 
Less than 12 months
 
12 months or longer
(In millions)
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
$
74

 
 
 
$
1

 
 
 
$
74

 
 
 
$
1

 
 
 
$
0

 
 
 
$
0

 
  Japan government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
5,255

 
 
 
271

 
 
 
1,264

 
 
 
9

 
 
 
3,991

 
 
 
262

 
  Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
129

 
 
 
12

 
 
 
10

 
 
 
0

 
 
 
119

 
 
 
12

 
  Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
785

 
 
 
27

 
 
 
221

 
 
 
3

 
 
 
564

 
 
 
24

 
  Yen-denominated
 
83

 
 
 
6

 
 
 
0

 
 
 
0

 
 
 
83

 
 
 
6

 
  Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
309

 
 
 
1

 
 
 
309

 
 
 
1

 
 
 
0

 
 
 
0

 
  Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
362

 
 
 
8

 
 
 
316

 
 
 
5

 
 
 
46

 
 
 
3

 
  Yen-denominated
 
1,507

 
 
 
62

 
 
 
394

 
 
 
4

 
 
 
1,113

 
 
 
58

 
  Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
7,741

 
 
 
418

 
 
 
2,839

 
 
 
50

 
 
 
4,902

 
 
 
368

 
  Yen-denominated
 
440

 
 
 
7

 
 
 
349

 
 
 
4

 
 
 
91

 
 
 
3

 
  Total
 
$
16,685

 
 
 
$
813

 
 
 
$
5,776

 
 
 
$
77

 
 
 
$
10,909

 
 
 
$
736

 

(1) Includes perpetual securities

Analysis of Securities in Unrealized Loss Positions

The unrealized losses on the Company's fixed maturity securities investments have been primarily related to general market changes in interest rates, foreign exchange rates, and/or the levels of credit spreads rather than specific concerns with the issuer's ability to pay interest and repay principal.

For any significant declines in fair value of its fixed maturity securities, the Company performs a more focused review of the related issuers' credit profile. For corporate issuers, the Company evaluates their assets, business profile including industry dynamics and competitive positioning, financial statements and other available financial data. For non-corporate issuers, the Company analyzes all sources of credit support, including issuer-specific factors. The Company utilizes information available in the public domain and, for certain private placement issuers, from consultations with the issuers directly. The Company also considers ratings from Nationally Recognized Statistical Rating Organizations (NRSROs), as well as the specific characteristics of the security it owns including seniority in the issuer's capital structure, covenant predictions, or other relevant features. From these reviews, the Company evaluates the issuers' continued ability to service the Company's investment through payment of interest and principal.

Assuming no credit-related factors develop, unrealized gains and losses on fixed maturity securities are expected to diminish as investments near maturity. Based on its credit analysis, the Company believes that the issuers of its fixed maturity investments in the sectors shown in the table above have the ability to service their obligations to the Company.

Other Investments

The table below reflects the composition of the carrying value for other investments as of December 31.
(In millions)
2018
 
2017
Other investments:
 
 
 
 
 
 
 
Transitional real estate loans
 
$
4,377

 
 
 
$
1,235

 
Commercial mortgage loans
 
1,064

 
 
 
908

 
Middle market loans
 
1,478

 
 
 
859

 
Policy loans
 
232

 
 
 
210

 
Short-term investments
 
152

 
 
 
57

 
Other
 
403

 
 
 
133

 
Total other investments
 
$
7,706

 
 
 
$
3,402

 


Loans and Loan Receivables

The Company classifies its TREs, CMLs, and MMLs as held-for investment and includes them in the other investments line on the consolidated balance sheets. The Company carries them on the balance sheet at amortized cost less an estimated allowance for loan losses. The Company's allowance for loan losses is established using both general and specific allowances. The general allowance is used for loans grouped by similar risk characteristics where a loan-specific or market-specific risk has not been identified, but for which the Company estimates probable incurred losses. The specific allowance is used on an individual loan basis when it is probable that a loss has been incurred. As of December 31, 2018 and 2017, the Company's allowance for loan losses was $27 million and $11 million, respectively. As of December 31, 2018 and 2017, the Company had no loans that were past due in regards to principal and/or interest payments. Additionally, the Company held no loans that were on nonaccrual status or considered impaired as of December 31, 2018 and 2017. The Company had no troubled debt restructurings during the years ended December 31, 2018 and 2017.

Transitional Real Estate Loans

Transitional real estate loans are commercial mortgage loans that are typically relatively short-term floating rate instruments secured by a first lien on the property. These loans provide funding for properties undergoing a change in their physical characteristics and/or economic profile. As of December 31, 2018, the Company had $605 million in outstanding commitments to fund transitional real estate loans. These commitments are contingent on the final underwriting and due diligence to be performed.

Commercial Mortgage Loans

As of December 31, 2018, the Company had $25 million in outstanding commitments to fund commercial mortgage loans. These commitments are contingent on the final underwriting and due diligence to be performed.

Middle Market Loans

Middle market loans are generally considered to be below investment grade. The carrying value for middle market loans included an unfunded amount of $56 million and $109 million, as of December 31, 2018, and 2017, respectively, that is reflected in other liabilities on the consolidated balance sheets.

As of December 31, 2018, the Company had commitments of approximately $521 million to fund potential future loan originations related to this investment program. These commitments are contingent upon the availability of middle market loans that meet the Company's underwriting criteria.

Other

Other investments primarily includes investments in limited partnerships. As of December 31, 2018, the Company had $916 million in outstanding commitments to fund alternative investments in limited partnerships.Variable Interest Entities (VIEs)

As a condition of its involvement or investment in a VIE, the Company enters into certain protective rights and covenants that preclude changes in the structure of the VIE that would alter the creditworthiness of the Company's investment or its beneficial interest in the VIE.

For those VIEs other than certain unit trust structures, the Company's involvement is passive in nature. The Company has not, nor has it been, required to purchase any securities issued in the future by these VIEs.

The Company's ownership interest in VIEs is limited to holding the obligations issued by them. The Company has no direct or contingent obligations to fund the limited activities of these VIEs, nor does it have any direct or indirect financial guarantees related to the limited activities of these VIEs. The Company has not provided any assistance or any other type of financing support to any of the VIEs it invests in, nor does it have any intention to do so in the future. For those VIEs in which the Company holds debt obligations, the weighted-average lives of the Company's notes are very similar to the underlying collateral held by these VIEs where applicable.

The Company's risk of loss related to its interests in any of its VIEs is limited to the carrying value of the related investments held in the VIE.

VIEs - Consolidated

The following table presents the cost or amortized cost, fair value and balance sheet caption in which the assets and liabilities of consolidated VIEs are reported as of December 31.
Investments in Consolidated Variable Interest Entities
  
2018
 
2017
(In millions)
Cost or Amortized
Cost
 
Fair
Value
 
Cost or Amortized
Cost
 
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
3,849

 
 
 
$
4,466

 
 
 
$
4,538

 
 
 
$
5,509

 
Equity securities
 
160

 
 
 
160

 
 
 
606

 
 
 
753

 
Other investments (2)
 
5,856

 
 
 
5,834

 
 
 
2,341

 
 
 
2,328

 
Other assets (3)
 
182

 
 
 
182

 
 
 
151

 
 
 
151

 
Total assets of consolidated VIEs
 
$
10,047

 
 
 
$
10,642

 
 
 
$
7,636

 
 
 
$
8,741

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities (3)
 
$
102

 
 
 
$
102

 
 
 
$
128

 
 
 
$
128

 
Total liabilities of consolidated VIEs
 
$
102

 
 
 
$
102

 
 
 
$
128

 
 
 
$
128

 

(1) Includes perpetual securities
(2) Consists of TREs, CMLs, MMLs, and alternative investments in limited partnerships
(3) Consists entirely of derivatives

The Company is substantively the only investor in the consolidated VIEs listed in the table above. As the sole investor in these VIEs, the Company has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and is therefore considered to be the primary beneficiary of the VIEs that it consolidates. The Company also participates in substantially all of the variability created by these VIEs. The activities of these VIEs are limited to holding invested assets and foreign currency swaps, as appropriate, and utilizing the cash flows from these securities to service its investment. Neither the Company nor any of its creditors are able to obtain the underlying collateral of the VIEs unless there is an event of default or other specified event. For those VIEs that contain a swap, the Company is not a direct counterparty to the swap contracts and has no control over them. The Company's loss exposure to these VIEs is limited to its original investment. The Company's consolidated VIEs do not rely on outside or ongoing sources of funding to support their activities beyond the underlying collateral and swap contracts, if applicable. With the exception of its investments in unit trust structures, the underlying collateral assets and funding of the Company's consolidated VIEs are generally static in nature.

Investments in Unit Trust Structures

The Company also utilizes unit trust structures in its Aflac Japan segment to invest in various asset classes. As the sole investor of these VIEs, the Company is required to consolidate these trusts under U.S. GAAP.

VIEs - Not Consolidated

The table below reflects the amortized cost, fair value and balance sheet caption in which the Company's investment in VIEs not consolidated are reported as of December 31.

Investments in Variable Interest Entities Not Consolidated
 
2018
 
2017
(In millions)
Amortized
Cost
 
Fair
Value
 
Amortized
Cost
 
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
4,575

 
 
 
$
4,982

 
 
 
$
5,004

 
 
 
$
5,724

 
Fixed maturity securities, held to maturity
 
2,007

 
 
 
2,254

 
 
 
2,549

 
 
 
2,929

 
Other investments
 
49

 
 
 
49

 
 
 
55

 
 
 
55

 
Total investments in VIEs not consolidated
 
$
6,631

 
 
 
$
7,285

 
 
 
$
7,608

 
 
 
$
8,708

 

(1) Includes perpetual securities

The Company holds alternative investments in limited partnerships that have been determined to be VIEs. These partnerships invest in private equity and structured investments. The Company’s maximum exposure to loss on these investments is limited to the amount of its investment. The Company is not the primary beneficiary of these VIEs and is therefore not required to consolidate them. The Company classifies these investments as Other investments in the consolidated balance sheets.

Certain investments in VIEs that the Company is not required to consolidate are investments that are in the form of debt obligations from the VIEs that are irrevocably and unconditionally guaranteed by their corporate parents or sponsors. These VIEs are the primary financing vehicles used by their corporate sponsors to raise financing in the capital markets. The variable interests created by these VIEs are principally or solely a result of the debt instruments issued by them. The Company does not have the power to direct the activities that most significantly impact the entity's economic performance, nor does it have the obligation to absorb losses of the entity or the right to receive benefits from the entity. As such, the Company is not the primary beneficiary of these VIEs and is therefore not required to consolidate them.Securities Lending and Pledged Securities

The Company lends fixed maturity and public equity securities to financial institutions in short-term security-lending transactions. These short-term security-lending arrangements increase investment income with minimal risk. The Company's security lending policy requires that the fair value of the securities received as collateral be 102% or more of the fair value of the loaned securities and that unrestricted cash received as collateral be 100% or more of the fair value of the loaned securities. These securities continue to be carried as investment assets on the Company's balance sheet during the terms of the loans and are not reported as sales. The Company receives cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. For loans where the Company receives as collateral securities that the Company is not permitted to sell or repledge, the collateral is not reported as an asset.

Details of our securities lending activities as of December 31 were as follows:
Securities Lending Transactions Accounted for as Secured Borrowings
2018
Remaining Contractual Maturity of the Agreements
(In millions)
Overnight
and
Continuous(1)
 
Up to 30
days
 
Greater
than 90
days
 
Total
Securities lending transactions:
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
Japan government and agencies
$
0

 
$
387

 
$
1,190

 
$
1,577

Municipalities
5

 
0

 
0

 
5

Public utilities
27

 
0

 
0

 
27

Banks/financial institutions
74

 
0

 
0

 
74

Other corporate
549

 
0

 
0

 
549

Equity securities
10

 
0

 
0

 
10

          Total borrowings
$
665

 
$
387

 
$
1,190

 
$
2,242

Gross amount of recognized liabilities for securities lending transactions
 
 
$
1,052

Amounts related to agreements not included in offsetting disclosure in Note 4
 
 
$
1,190

(1) These securities are pledged as collateral under the Company's U.S. securities lending program and can be called at its discretion; therefore, they are classified as Overnight and Continuous.
Securities Lending Transactions Accounted for as Secured Borrowings
2017
Remaining Contractual Maturity of the Agreements
(In millions)
Overnight
and
Continuous(1)
 
Up to 30
days
 
 
Total
Securities lending transactions:
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
Japan government and agencies
$
0

 
$
49

 
 
$
49

Public utilities
73

 
0

 
 
73

Banks/financial institutions
54

 
0

 
 
54

Other corporate
415

 
0

 
 
415

Equity securities
15

 
0

 
 
15

          Total borrowings
$
557

 
$
49

 
 
$
606

Gross amount of recognized liabilities for securities lending transactions
 
$
606

Amounts related to agreements not included in offsetting disclosure in Note 4
 
$
0


(1) These securities are pledged as collateral under the Company's U.S. securities lending program and can be called at its discretion; therefore, they are classified as Overnight and Continuous.

The Company did not have any repurchase agreements or repurchase-to-maturity transactions outstanding as of December 31, 2018 and 2017, respectively.

Certain fixed maturity securities can be pledged as collateral as part of derivative transactions, or pledged to support state deposit requirements on certain investment programs. For additional information regarding pledged securities related to derivative transactions, see Note 4.

At December 31, 2018, debt securities with a fair value of $19 million were on deposit with regulatory authorities in the United States (including U.S. territories) and Japan. The Company retains ownership of all securities on deposit and receives the related investment income.

For general information regarding the Company's investment accounting policies, see Note 1.
v3.10.0.1
DERIVATIVE INSTRUMENTS
 12 Months Ended
Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
DERIVATIVE INSTRUMENTS DERIVATIVE INSTRUMENTS
The Company's freestanding derivative financial instruments have historically consisted of: (1) foreign currency forwards and options used in hedging foreign exchange risk on U.S. dollar-denominated investments in Aflac Japan's portfolio; (2) foreign currency forwards and options used to economically hedge certain portions of forecasted cash flows denominated in yen and hedge the Company's long term exposure to a weakening yen; (3) cross-currency interest rate swaps, also referred to as foreign currency swaps, associated with certain senior notes and subordinated debentures; (4) foreign currency swaps and, in prior periods, credit default swaps that are associated with investments in special-purpose entities, including VIEs where the Company is the primary beneficiary; (5) interest rate swaps used to economically hedge interest rate fluctuations in certain variable-rate investments; and (6) interest rate swaptions used to hedge changes in the fair value associated with interest rate fluctuations for certain U.S. dollar-denominated available-for-sale fixed-maturity securities. Some of the Company's derivatives are designated as cash flow hedges, fair value hedges or net investment hedges; however, other derivatives do not qualify for hedge accounting or the Company elects not to designate them as accounting hedges.

Derivative Types

Foreign currency forwards and options are executed for the Aflac Japan segment in order to hedge the currency risk on the carrying value of certain U.S. dollar-denominated investments. The average maturity of these forwards and options can change depending on factors such as market conditions and types of investments being held. In situations where the maturity of the forwards and options is shorter than the underlying investment being hedged, the Company may enter into new forwards and options near maturity of the existing derivative in order to continue hedging the underlying investment. In forward transactions, Aflac Japan agrees with another party to buy a fixed amount of yen and sell a corresponding amount of U.S. dollars at a specified future date. Aflac Japan also executes foreign currency option transactions in a collar strategy, where Aflac Japan agrees with another party to simultaneously purchase put options and sell call options. In the purchased put transactions, Aflac Japan obtains the option to buy a fixed amount of yen and sell a corresponding amount of U.S. dollars at a specified future date. In the sold call transaction, Aflac Japan agrees to sell a fixed amount of yen and buy a corresponding amount of U.S. dollars at a specified future date. The combination of purchasing the put option and selling the call option results in no net premium being paid (i.e. a costless or zero-cost collar). The foreign currency forwards and options are used in fair value hedging relationships to mitigate the foreign exchange risk associated with U.S. dollar-denominated investments supporting yen- denominated liabilities.

Prior to April 1, 2018, foreign currency forwards and options (through a collar strategy, as discussed above) were used to hedge the currency risk associated with the net investment in Aflac Japan. In these forward transactions, Aflac agreed with another party to buy a fixed amount of U.S. dollars and sell a corresponding amount of yen at a specified price at a specified future date. In the option transactions, the Company used a combination of foreign currency options to protect expected future cash flows by simultaneously purchasing yen put options (options that protect against a weakening yen) and selling yen call options (options that limit participation in a strengthening yen). The combination of these two actions created a zero-cost collar.

The Company enters into foreign currency swaps pursuant to which it exchanges an initial principal amount in one currency for an initial principal amount of another currency, with an agreement to re-exchange the principal amounts at a future date. There may also be periodic exchanges of payments at specified intervals based on the agreed upon rates and notional amounts. Foreign currency swaps are used primarily in the consolidated VIEs in the Company's Aflac Japan portfolio to convert foreign-denominated cash flows to yen, the functional currency of Aflac Japan, in order to minimize cash flow fluctuations. The Company also uses foreign currency swaps to economically convert certain of its U.S. dollar-denominated senior note and subordinated debenture principal and interest obligations into yen-denominated obligations.

In order to reduce investment income volatility from its variable-rate investments, the Company enters into receive–fixed, pay–floating interest rate swaps. These derivatives are cleared and settled through a central clearinghouse.

Interest rate swaption collars are combinations of two swaption positions. Swaptions are used to mitigate the adverse impact resulting from significant changes in the fair value of U.S. dollar-denominated available-for-sale securities due to fluctuation in interest rates. In order to maximize the efficiency of the collars while minimizing cost, a collar strategy is used whereby the Company purchases a long payer swaption (the Company purchases an option that allows it to enter into a swap where the Company will pay the fixed rate and receive the floating rate of the swap) and sells a short receiver swaption (the Company sells an option that provides the counterparty with the right to enter into a swap where the Company will receive the fixed rate and pay the floating rate of the swap). The combination of purchasing the long payer swaption and selling the short receiver swaption results in no net premium being paid (i.e. a costless or zero-cost collar).

Derivative Balance Sheet Classification
The tables below summarize the balance sheet classification of the Company's derivative fair value amounts, as well as the gross asset and liability fair value amounts, at December 31. The fair value amounts presented do not include income accruals. The notional amount of derivative contracts represents the basis upon which pay or receive amounts are calculated and are not reflective of exposure or credit risk.

2018
 
2017
(In millions)
 
 
 
 
Asset
Derivatives
 
Liability
Derivatives
 
 
Asset
Derivatives
 
Liability
Derivatives
Hedge Designation/ Derivative
Type
Notional
Amount
 
Fair Value
 
Fair Value
Notional
Amount
 
Fair Value
 
Fair Value
Cash flow hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
75

 
 
 
$
1

 
 
 
$
(4
)
 
 
$
75

 
 
 
$
0

 
 
 
$
(8
)
 
Total cash flow hedges
 
75

 
 
 
1

 
 
 
(4
)
 
 
75

 
 
 
0

 
 
 
(8
)
 
Fair value hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency forwards
 
2,086

 
 
 
0

 
 
 
(34
)
 
 
7,640

 
 
 
2

 
 
 
(221
)
 
Foreign currency options
 
9,070

 
 
 
3

 
 
 
(1
)
 
 
7,670

 
 
 
0

 
 
 
(2
)
 
Interest rate swaptions
 
500

 
 
 
0

 
 
 
(1
)
 
 
0

 
 
 
0

 
 
 
0

 
Total fair value hedges
 
11,656

 
 
 
3

 
 
 
(36
)
 
 
15,310

 
 
 
2

 
 
 
(223
)
 
Net investment hedge:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency forwards
 
0

 
 
 
0

 
 
 
0

 
 
5

 
 
 
0

 
 
 
0

 
Foreign currency options
 
0

 
 
 
0

 
 
 
0

 
 
434

 
 
 
12

 
 
 
(1
)
 
Total net investment hedge
 
0

 
 
 
0

 
 
 
0

 
 
439

 
 
 
12

 
 
 
(1
)
 
Non-qualifying strategies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
5,387

 
 
 
284

 
 
 
(230
)
 
 
5,386

 
 
 
296

 
 
 
(189
)
 
Foreign currency forwards
 
16,057

 
 
 
126

 
 
 
(117
)
 
 
3,683

 
 
 
20

 
 
 
(53
)
 
Foreign currency options
 
430

 
 
 
0

 
 
 
0

 
 
770

 
 
 
0

 
 
 
0

 
Credit default swaps
 
0

 
 
 
0

 
 
 
0

 
 
88

 
 
 
1

 
 
 
0

 
Interest rate swaps
 
4,750

 
 
 
3

 
 
 
0

 
 
0

 
 
 
0

 
 
 
0

 
Total non-qualifying strategies
 
26,624

 
 
 
413

 
 
 
(347
)
 
 
9,927

 
 
 
317

 
 
 
(242
)
 
Total derivatives
 
$
38,355

 
 
 
$
417

 
 
 
$
(387
)
 
 
$
25,751

 
 
 
$
331

 
 
 
$
(474
)
 
Balance Sheet Location
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other assets
 
$
23,713

 
 
 
$
417

 
 
 
$
0

 
 
$
10,948

 
 
 
$
331

 
 
 
$
0

 
Other liabilities
 
14,642

 
 
 
0

 
 
 
(387
)
 
 
14,803

 
 
 
0

 
 
 
(474
)
 
Total derivatives
 
$
38,355

 
 
 
$
417

 
 
 
$
(387
)
 
 
$
25,751

 
 
 
$
331

 
 
 
$
(474
)
 


Cash Flow Hedges

For certain variable-rate U.S. dollar-denominated available-for-sale securities held by Aflac Japan via consolidated VIEs, foreign currency swaps are used to swap the USD variable rate interest and principal payments to fixed rate JPY interest and principal payments. The Company has designated foreign currency swaps as a hedge of the variability in cash flows of a forecasted transaction or of amounts to be received or paid related to a recognized asset (“cash flow” hedge). The remaining maximum length of time for which these cash flows are hedged is seven years. The derivatives in the Company's consolidated VIEs that are not designated as accounting hedges are discussed in the "non-qualifying strategies" section of this note.
Fair Value Hedges
The Company designates and accounts for certain foreign currency forwards, options, and interest rate swaptions as fair value hedges when they meet the requirements for hedge accounting. The Company recognizes gains and losses on these derivatives as well as the offsetting gain or loss on the related hedged items in current earnings.

Foreign currency forwards and options hedge the foreign currency exposure of certain U.S. dollar-denominated available-for-sale fixed-maturity investments held in Aflac Japan. The change in the fair value of the foreign currency forwards related to the changes in the difference between the spot rate and the forward price is excluded from the assessment of hedge effectiveness. The change in fair value of the foreign currency option related to the time value of the option is recognized in current earnings and is excluded from the assessment of hedge effectiveness.

Interest rate swaptions hedge the interest rate exposure of certain U.S. dollar-denominated available-for-sale securities held in Aflac Japan. For these hedging relationships, the Company excludes time value from the assessment of hedge effectiveness and recognizes changes in the intrinsic value of the swaptions in current earnings within net investment income. The change in the time value of the swaptions is recognized in other comprehensive income (loss) and amortized into earnings (net investment income) over its legal term.

The following table presents the gains and losses on derivatives and the related hedged items in fair value hedges for the years ended December 31.

Fair Value Hedging Relationships
(In millions)
 
 
Hedging Derivatives
 
Hedged Items
 
 
Hedging Derivatives
Hedged Items
 
Total
Gains
(Losses)
 
Gains (Losses)
Excluded from Effectiveness Testing(2)
 
Gains (Losses)
Included in Effectiveness Testing(1)
 
 Gains (Losses) (1)
 
Net Realized Gains (Losses) Recognized for Fair Value Hedge
2018:
 
 
 
 
 
 
 
 
 
 
Foreign currency
forwards
Fixed maturity securities
 
$
126

 
$
(104
)
 
$
230

 
$
(242
)
 
$
(12
)
Foreign currency
options
Fixed maturity securities
 
4

 
4

 
0

 
0

 
0

Interest rate
swaptions
Fixed maturity securities
 
(1
)
 
(1
)
 
0

 
0

 
0

   Total gains (losses)
 
$
129

 
$
(101
)
 
$
230

 
$
(242
)
 
$
(12
)
2017:
 
 
 
 
 
 
 
Foreign currency forwards
Fixed maturity and equity securities
 
$
98

 
$
(202
)
 
$
300

 
$
(278
)
 
$
22

Foreign currency options
Fixed maturity securities
 
21

 
10

 
11

 
(10
)
 
1

    Total gains (losses)
 
$
119

 
$
(192
)
 
$
311

 
$
(288
)
 
$
23

2016:
 
 
 
 
 
 
 
Foreign currency forwards
Fixed maturity and equity securities
 
$
207

 
$
(338
)
 
$
545

 
$
(566
)
 
$
(21
)
Foreign currency options
Fixed maturity securities
 
(95
)
 
(18
)
 
(77
)
 
70

 
(7
)
    Total gains (losses)
 
$
112

 
$
(356
)
 
$
468

 
$
(496
)
 
$
(28
)

(1) Gains and losses on foreign currency forwards and options and related hedged items are reported in the consolidated statement of earnings as realized investment gains (losses). For interest rate swaptions and related hedged items, gains and losses included in the hedge assessment are reported within net investment income. For the year ended December 31, 2018, those gains and losses on interest rate swaptions and related hedged items were immaterial.
(2) Gains (losses) excluded from effectiveness testing includes the forward point on foreign currency forwards and time value change on foreign currency options which are reported in the consolidated statement of earnings as realized investment gains (losses). It also includes the change in the fair value of the interest rate swaptions related to the time value of the swaptions which is recognized as a component of other comprehensive income (loss).

The following table shows the December 31, 2018 carrying amounts of assets designated and qualifying as hedged items in fair value hedges of interest rate risk and the related cumulative hedge adjustment included in the carrying amount.
(In millions)
Carrying Amount of the Hedged Assets/(Liabilities)(1)
 
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Assets/(Liabilities)
 
 
2018
 
 
 
2018
 
Fixed maturity securities
 
$
6,593

 
 
 
$
294

 
(1) The balance includes $294 million of hedging adjustment on discontinued hedging relationships.
As of December 31, 2018, the total notional amount of the Company's interest rate swaptions was $500 million. The hedging adjustment related to these derivatives was immaterial.

Net Investment Hedge

The Company's investment in Aflac Japan is affected by changes in the yen/dollar exchange rate. To mitigate this exposure, the Parent Company's yen-denominated liabilities (see Note 9) have been designated as non-derivative hedges and, prior to April 1, 2018, foreign currency forwards and options were designated as derivative hedges of the foreign currency exposure of the Company's net investment in Aflac Japan. The Company designated net investment hedges under this strategy during the years ended December 31, 2018, 2017 and 2016.
Non-qualifying Strategies
For the Company's derivative instruments in consolidated VIEs that do not qualify for hedge accounting treatment, all changes in their fair value are reported in current period earnings within realized investment gains (losses). The amount of gain or loss recognized in earnings for the Company's VIEs is attributable to the derivatives in those investment structures. While the change in value of the swaps is recorded through current period earnings, the change in value of the available-for-sale fixed maturity securities associated with these swaps is recorded through other comprehensive income.
As of December 31, 2018, the Parent Company had cross-currency interest rate swap agreements related to its $350 million senior notes due February 2022, $700 million senior notes due June 2023, $750 million senior notes due November 2024 and $450 million senior notes due March 2025. Changes in the values of these swaps are recorded through current period earnings. For additional information regarding these swaps, see Note 9.

The Company uses foreign exchange forwards and options to economically mitigate the currency risk of some of its U.S. dollar- denominated loan receivables held within the Aflac Japan segment. These arrangements are not designated as accounting hedges, as the foreign currency remeasurement of the loan receivables impacts current period earnings, and generally offsets gains and losses from foreign exchange forwards within realized investment gains (losses). The Company also has certain foreign exchange forwards on U.S. dollar-denominated AFS securities where hedge accounting is not being applied.
In order to economically mitigate currency risk of future yen dividends from Aflac Japan while lowering consolidated hedge costs associated with Aflac Japan's U.S. dollar investment hedging the Parent Company entered into offsetting hedge positions using foreign exchange forwards. This activity is reported in the Corporate and other segment.

The Company uses interest rate swaps to economically convert the variable rate investment income to a fixed rate on certain variable-rate investments.

Impact of Derivatives and Hedging Instruments

The following table summarizes the impact to realized investment gains (losses) and other comprehensive income (loss) from all derivatives and hedging instruments for the years ended December 31.
 
2018
2017
2016
(In millions)
Realized Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Realized Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Realized
Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Qualifying hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Cash flow hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
$
0

 
 
$
3

 
 
$
0

 
 
$
1

 
 
$
1

 
 
$
3

 
  Total cash flow hedges
 
0

(2) 
 
3

 
 
0

(2) 
 
1

 
 
1

(2) 
 
3

 
  Fair value hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency forwards (3)
 
(116
)
 
 
 
 
 
(180
)
 
 
 
 
 
(359
)
 
 
 
 
       Foreign currency options (3)
 
4

 
 
 
 
 
11

 
 
 
 
 
(25
)
 
 
 
 
       Interest rate swaptions (3)
 
0

 
 
(1
)
 
 
0

 
 
0

 
 
0

 
 
0

 
  Total fair value hedges
 
(112
)
 
 
(1
)
 
 
(169
)
 
 
0

 
 
(384
)
 
 
0

 
  Net investment hedge:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Non-derivative hedging
instruments
 
0

 
 
(32
)
 
 
0

 
 
(15
)
 
 
0

 
 
0

 
       Foreign currency forwards
 
0

 
 
0

 
 
0

 
 
(25
)
 
 
0

 
 
(118
)
 
       Foreign currency options
 
0

 
 
(8
)
 
 
0

 
 
5

 
 
0

 
 
73

 
   Total net investment hedge
 
0

 
 
(40
)
 
 
0

 
 
(35
)
 
 
0

 
 
(45
)
 
  Non-qualifying strategies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
20

 
 
 
 
 
53

 
 
 
 
 
117

 
 
 
 
       Foreign currency forwards
 
(135
)
 
 
 
 
 
8

 
 
 
 
 
9

 
 
 
 
       Credit default swaps
 
0

 
 
 
 
 
(1
)
 
 
 
 
 
2

 
 
 
 
       Interest rate swaps
 
3

 
 
 
 
 
0

 
 
 
 
 
0

 
 
 
 
  Total non- qualifying strategies
 
(112
)
 
 
 
 
 
60

 
 
 
 
 
128

 
 
 
 
          Total
 
$
(224
)
 
 
$
(38
)
 
 
$
(109
)
 
 
$
(34
)
 
 
$
(255
)
 
 
$
(42
)
 
(1) Cash flow hedge items and the change in the fair value of interest rate swaptions related to the time value of the swaptions in fair value hedges are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss).
(2) Impact of cash flow hedges reported as realized investment gains (losses) includes an immaterial amount of gains or losses reclassified from accumulated other comprehensive income (loss) into earnings. It also includes an immaterial amount excluded from effectiveness testing during the years ended December 31, 2018 and 2017 and $1 million during the year ended December 31, 2016.
(3)Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail)

The impact on earnings from derivatives in cash flow hedge relationships also included a loss of $2 million during the year ended December 31, 2018 and an immaterial amount during the years ended December 31, 2017 and 2016 resulting from reclassifications from accumulated other comprehensive income (loss) to net investment income. There was no gain or loss reclassified from accumulated other comprehensive income (loss) into earnings related to the net investment hedge for the years ended December 31, 2018, 2017 and 2016. As of December 31, 2018, deferred gains and losses on derivative instruments recorded in accumulated other comprehensive income that are expected to be reclassified to earnings during the next twelve months were immaterial.

Credit Risk Assumed through Derivatives

For the foreign currency and credit default swaps associated with the Company's VIE investments for which it is the primary beneficiary, the Company bears the risk of loss due to counterparty default even though it is not a direct counterparty to those contracts.

The Company is a direct counterparty to the foreign currency swaps that it has entered into in connection with certain of its senior notes and subordinated debentures; foreign currency forwards; and foreign currency options, and therefore the Company is exposed to credit risk in the event of nonperformance by the counterparties in those contracts. The risk of counterparty default for the Company's foreign currency swaps, certain foreign currency forwards, foreign currency options is mitigated by collateral posting requirements that counterparties to those transactions must meet.

As of December 31, 2018, there were 16 counterparties to the Company's derivative agreements, with three comprising 52% of the aggregate notional amount. The counterparties to these derivatives are financial institutions with the following credit ratings as of December 31:
 
2018
2017
(In millions)
Notional Amount
of Derivatives
Asset Derivatives
Fair Value
Liability Derivatives
Fair Value
Notional Amount
of Derivatives
Asset Derivatives
Fair Value
Liability Derivatives
Fair Value
Counterparties' credit rating:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
AA
 
$
5,399

 
 
$
63

 
 
$
(23
)
 
 
$
4,708

 
 
$
52

 
 
$
(37
)
 
A
 
32,513

 
 
350

 
 
(311
)
 
 
20,604

 
 
271

 
 
(370
)
 
BBB
 
443

 
 
4

 
 
(53
)
 
 
439

 
 
8

 
 
(67
)
 
Total
 
$
38,355

 
 
$
417

 
 
$
(387
)
 
 
$
25,751

 
 
$
331

 
 
$
(474
)
 


The Company engages in over-the-counter (OTC) bilateral derivative transactions directly with unaffiliated third parties under International Swaps and Derivatives Association, Inc. (ISDA) agreements and other documentation. Most of the ISDA agreements also include Credit Support Annexes (CSAs) provisions, which generally provide for two-way collateral postings at the first dollar of exposure. The Company mitigates the risk that counterparties to transactions might be unable to fulfill their contractual obligations by monitoring counterparty credit exposure and collateral value while generally requiring that collateral be posted at the outset of the transaction. In addition, a significant portion of the derivative transactions have provisions that give the counterparty the right to terminate the transaction upon a downgrade of Aflac’s financial strength rating. The actual amount of payments that the Company could be required to make depends on market conditions, the fair value of outstanding affected transactions, and other factors prevailing at and after the time of the downgrade.

The Company also engages in OTC cleared derivative transactions through regulated central clearing counterparties. These positions are marked to market and margined on a daily basis (both initial margin and variation margin), and the Company has minimal exposure to credit-related losses in the event of nonperformance by counterparties to these derivatives.

Collateral posted by the Company to third parties for derivative transactions can generally be repledged or resold by the counterparties. The aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a net liability position by counterparty was approximately $139 million and $264 million as of December 31, 2018 and 2017, respectively. If the credit-risk-related contingent features underlying these agreements had been triggered on December 31, 2018, the Company estimates that it would be required to post a maximum of $34 million of additional collateral to these derivative counterparties. The Company is generally allowed to sell or repledge collateral obtained from its derivative counterparties, although it does not typically exercise such rights. (See the Offsetting tables below for collateral posted or received as of the reported balance sheet dates.)

Offsetting of Financial Instruments and Derivatives

Most of the Company's derivative instruments are subject to enforceable master netting arrangements that provide for the net settlement of all derivative contracts between the Parent Company or Aflac and its respective counterparty in the event of default or upon the occurrence of certain termination events. Collateral support agreements with the master netting arrangements generally provide that the Company will receive or pledge financial collateral at the first dollar of exposure.

The Company has securities lending agreements with unaffiliated financial institutions that post collateral to the Company in return for the use of its fixed maturity and public equity securities (see Note 3). When the Company has entered into securities lending agreements with the same counterparty, the agreements generally provide for net settlement in the event of default by the counterparty. This right of set-off allows the Company to keep and apply collateral received if the counterparty failed to return the securities borrowed from the Company as contractually agreed. For additional information on the Company's accounting policy for securities lending, see Note 1.

The tables below summarize the Company's derivatives and securities lending transactions as of December 31, and as reflected in the tables, in accordance with U.S. GAAP, the Company's policy is to not offset these financial instruments in the Consolidated Balance Sheets.

Offsetting of Financial Assets and Derivative Assets
2018
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Assets
 
Gross Amount
Offset in
Balance Sheet
 
Net Amount of Assets Presented
 in Balance Sheet
 
Financial Instruments
 
Securities
Collateral
 
Cash Collateral Received
 
Net Amount
Derivative
  assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      assets subject to a
      master netting
      agreement or
      offsetting
      arrangement
 

 
 
 

 
 
 

 
 
 

 
 


 
 

 
 
 

 
          OTC - bilateral
 
$
231

 
 
 
$
0

 
 
 
$
231

 
 
 
$
(152
)
 
 
$
(23
)
 
 
$
(55
)
 
 
 
$
1

 
          OTC - cleared
 
3

 
 
 
0

 
 
 
3

 
 
 
0

 
 
0

 
 
(3
)
 
 
 
0

 
    Total derivative
assets subject to a
master netting
agreement or
offsetting
arrangement
 
234

 
 
 
0

 
 
 
234

 
 
 
(152
)
 
 
(23
)
 
 
(58
)
 
 
 
1

 
    Derivative
      assets not subject
      to a master netting
      agreement or
      offsetting
      arrangement
 

 
 
 

 
 
 

 
 
 

 
 


 
 

 
 
 

 
          OTC - bilateral
 
183

 
 
 
 
 
 
 
183

 
 
 
 
 
 
 
 
 
 
 
 
 
183

 
    Total derivative
assets not subject
to a master netting
agreement or
offsetting
arrangement
 
183

 
 
 
 
 
 
 
183

 
 
 
 
 
 
 
 
 
 
 
 
 
183

 
    Total derivative
      assets
 
417

 
 
 
0

 
 
 
417

 
 
 
(152
)
 
 
(23
)
 
 
(58
)
 
 
 
184

 
Securities lending
   and similar
   arrangements
 
1,029

 
 
 
0

 
 
 
1,029

 
 
 
0

 
 
0

 
 
(1,029
)
 
 
 
0

 
    Total
 
$
1,446

 
 
 
$
0

 
 
 
$
1,446

 
 
 
$
(152
)
 
 
$
(23
)
 
 
$
(1,087
)
 
 
 
$
184

 


2017
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Assets
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Assets Presented in Balance Sheet
 
Financial
Instruments
Securities Collateral
Cash Collateral Received
 
Net Amount
Derivative
  assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      assets subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
$
180

 
 
 
$
0

 
 
 
$
180

 
 
 
$
(82
)
 
 
$
0

 
 
$
(98
)
 
 
 
$
0

 
    Total derivative
assets subject to a
master netting
agreement or
offsetting
arrangement
 
180

 
 
 
0

 
 
 
180

 
 
 
(82
)
 
 
0

 
 
(98
)
 
 
 
0

 
    Derivative
      assets not subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
151

 
 
 
 
 
 
 
151

 
 
 
 
 
 
 
 
 
 
 
 
 
151

 
    Total derivative
assets not subject
to a master netting
agreement or
offsetting
arrangement
 
151

 
 
 
 
 
 
 
151

 
 
 
 
 
 
 
 
 
 
 
 
 
151

 
    Total derivative
      assets
 
331

 
 
 
0

 
 
 
331

 
 
 
(82
)
 
 
0

 
 
(98
)
 
 
 
151

 
Securities lending
   and similar
   arrangements
 
592

 
 
 
0

 
 
 
592

 
 
 
0

 
 
0

 
 
(592
)
 
 
 
0

 
    Total
 
$
923

 
 
 
$
0

 
 
 
$
923

 
 
 
$
(82
)
 
 
$
0

 
 
$
(690
)
 
 
 
$
151

 




Offsetting of Financial Liabilities and Derivative Liabilities
2018
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Liabilities
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Liabilities Presented in Balance Sheet
 
Financial Instruments
 
Securities Collateral
 
Cash Collateral Pledged
 
Net Amount
Derivative
  liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      liabilities subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 


 
          OTC - bilateral
 
$
(285
)
 
 
 
$
0

 
 
 
$
(285
)
 
 
 
$
152

 
 
$
37

 
 
$
68

 
 
 
$
(28
)
 
    Total derivative
liabilities subject
to a master netting
agreement or
offsetting
arrangement
 
(285
)
 
 
 
0

 
 
 
(285
)
 
 
 
152

 
 
37

 
 
68

 
 
 
(28
)
 
    Derivative
      liabilities not
      subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 
 
 
 
 
 
 
 
 
 
 


 
          OTC - bilateral
 
(102
)
 
 
 
 
 
 
 
(102
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(102
)
 
    Total derivative
liabilities not
subject to a
master netting
agreement or
offsetting
arrangement
 
(102
)
 
 
 
 
 
 
 
(102
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(102
)
 
    Total derivative
      liabilities
 
(387
)
 
 
 
0

 
 
 
(387
)
 
 
 
152

 
 
37

 
 
68

 
 
 
(130
)
 
Securities lending
   and similar
   arrangements
 
(1,052
)
 
 
 
0

 
 
 
(1,052
)
 
 
 
1,029

 
 
0

 
 
0

 
 
 
(23
)
 
    Total
 
$
(1,439
)
 
 
 
$
0

 
 
 
$
(1,439
)
 
 
 
$
1,181

 
 
$
37

 
 
$
68

 
 
 
$
(153
)
 


2017
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Liabilities
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Liabilities Presented in Balance Sheet
 
Financial Instruments
 
Securities Collateral
 
Cash Collateral Pledged
 
Net Amount
Derivative
  liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      liabilities subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
$
(346
)
 
 
 
$
0

 
 
 
$
(346
)
 
 
 
$
82

 
 
$
245

 
 
$
10

 
 
 
$
(9
)
 
    Total derivative
liabilities subject
to a master netting
agreement or
offsetting
arrangement
 
(346
)
 
 
 
0

 
 
 
(346
)
 
 
 
82

 
 
245

 
 
10

 
 
 
(9
)
 
    Derivative
      liabilities not
      subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 
 
 
 
 
 
 
 
 
 
 

 
          OTC - bilateral
 
(128
)
 
 
 
 
 
 
 
(128
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(128
)
 
    Total derivative
liabilities not
subject to a
master netting
agreement or
offsetting
arrangement
 
(128
)
 
 
 
 
 
 
 
(128
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(128
)
 
    Total derivative
      liabilities
 
(474
)
 
 
 
0

 
 
 
(474
)
 
 
 
82

 
 
245

 
 
10

 
 
 
(137
)
 
Securities lending
   and similar
   arrangements
 
(606
)
 
 
 
0

 
 
 
(606
)
 
 
 
592

 
 
0

 
 
0

 
 
 
(14
)
 
    Total
 
$
(1,080
)
 
 
 
$
0

 
 
 
$
(1,080
)
 
 
 
$
674

 
 
$
245

 
 
$
10

 
 
 
$
(151
)
 


For additional information on the Company's financial instruments, see the accompanying Notes 1, 3 and 5.
v3.10.0.1
FAIR VALUE MEASUREMENTS
 12 Months Ended
Dec. 31, 2018
Fair Value Disclosures [Abstract]  
FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS
Fair Value Hierarchy

U.S. GAAP specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. These two types of inputs create three valuation hierarchy levels. Level 1 valuations reflect quoted market prices for identical assets or liabilities in active markets. Level 2 valuations reflect quoted market prices for similar assets or liabilities in an active market, quoted market prices for identical or similar assets or liabilities in non-active markets or model-derived valuations in which all significant valuation inputs are observable in active markets. Level 3 valuations reflect valuations in which one or more of the significant inputs are not observable in an active market.

The following tables present the fair value hierarchy levels of the Company's assets and liabilities that are measured and carried at fair value on a recurring basis as of December 31.
  
2018
(In millions)
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities available for sale, carried at
fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
32,993

 
 
 
$
1,349

 
 
 
$
0

 
 
 
$
34,342

 
Municipalities
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
Mortgage- and asset-backed securities
 
0

 
 
 
162

 
 
 
177

 
 
 
339

 
Public utilities
 
0

 
 
 
7,062

 
 
 
109

 
 
 
7,171

 
Sovereign and supranational
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
Banks/financial institutions
 
0

 
 
 
8,895

 
 
 
23

 
 
 
8,918

 
Other corporate
 
0

 
 
 
28,789

 
 
 
213

 
 
 
29,002

 
Total fixed maturity securities
 
32,993

 
 
 
49,380

 
 
 
522

 
 
 
82,895

(1) 
Equity securities (1)
 
874

 
 
 
67

 
 
 
46

 
 
 
987

(1) 
Other investments
 
152

 
 
 
0

 
 
 
0

 
 
 
152

 
Cash and cash equivalents
 
4,337

 
 
 
0

 
 
 
0

 
 
 
4,337

 
Other assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
0

 
 
 
103

 
 
 
182

 
 
 
285

 
Foreign currency forwards
 
0

 
 
 
126

 
 
 
0

 
 
 
126

 
Foreign currency options
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Interest rate swaps
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Total other assets
 
0

 
 
 
235

 
 
 
182

 
 
 
417

 
Total assets
 
$
38,356

 
 
 
$
49,682

 
 
 
$
750

 
 
 
$
88,788

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
0

 
 
 
$
132

 
 
 
$
102

 
 
 
$
234

 
Foreign currency forwards
 
0

 
 
 
151

 
 
 
0

 
 
 
151

 
Foreign currency options
 
0

 
 
 
1

 
 
 
0

 
 
 
1

 
Interest rate swaptions
 
0

 
 
 
1

 
 
 
0

 
 
 
1

 
Total liabilities
 
$
0

 
 
 
$
285

 
 
 
$
102

 
 
 
$
387

 

(1) Includes perpetual securities

  
2017
(In millions)
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities available for sale, carried at
fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
30,109

 
 
 
$
1,121

 
 
 
$
0

 
 
 
$
31,230

 
Municipalities
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
Mortgage- and asset-backed securities
 
0

 
 
 
269

 
 
 
175

 
 
 
444

 
Public utilities
 
0

 
 
 
7,886

 
 
 
68

 
 
 
7,954

 
Sovereign and supranational
 
0

 
 
 
1,909

 
 
 
0

 
 
 
1,909

 
Banks/financial institutions
 
0

 
 
 
8,908

 
 
 
25

 
 
 
8,933

 
Other corporate
 
0

 
 
 
32,327

 
 
 
146

 
 
 
32,473

 
Total fixed maturity securities
 
30,109

 
 
 
53,790

 
 
 
414

 
 
 
84,313

(1) 
Equity securities
 
1,001

 
 
 
6

 
 
 
16

 
 
 
1,023

 
Other investments
 
57

 
 
 
0

 
 
 
0

 
 
 
57

 
Cash and cash equivalents
 
3,491

 
 
 
0

 
 
 
0

 
 
 
3,491

 
Other assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
0

 
 
 
146

 
 
 
150

 
 
 
296

 
Foreign currency forwards
 
0

 
 
 
22

 
 
 
0

 
 
 
22

 
Foreign currency options
 
0

 
 
 
12

 
 
 
0

 
 
 
12

 
Credit default swaps
 
0

 
 
 
0

 
 
 
1

 
 
 
1

 
Total other assets
 
0

 
 
 
180

 
 
 
151

 
 
 
331

 
Total assets
 
$
34,658

 
 
 
$
53,976

 
 
 
$
581

 
 
 
$
89,215

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
0

 
 
 
$
69

 
 
 
$
128

 
 
 
$
197

 
Foreign currency forwards
 
0

 
 
 
274

 
 
 
0

 
 
 
274

 
Foreign currency options
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Total liabilities
 
$
0

 
 
 
$
346

 
 
 
$
128

 
 
 
$
474

 

(1) Includes perpetual securities

The following tables present the carrying amount and fair value categorized by fair value hierarchy level for the Company's financial instruments that are not carried at fair value as of December 31.
 
2018
(In millions)
Carrying
Value
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
Total
Fair
Value
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities held to maturity,
carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
21,712

 
 
$
27,030

 
 
 
$
8

 
 
 
$
0

 
 
 
$
27,038

 
Municipalities
 
359

 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
Mortgage and asset-backed
securities
 
14

 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
Public utilities
 
2,727

 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
Sovereign and
supranational
 
1,551

 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
Banks/financial institutions
 
1,445

 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
Other corporate
 
2,510

 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
Other investments (1)
 
6,945

 
 
0

 
 
 
26

 
 
 
6,893

 
 
 
6,919

 
 Total assets
 
$
37,263

 
 
$
27,030

 
 
 
$
9,703

 
 
 
$
6,908

 
 
 
$
43,641

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other policyholders’ funds
 
$
7,146

 
 
$
0

 
 
 
$
0

 
 
 
$
7,067

 
 
 
$
7,067

 
Notes payable
(excluding capital leases)
 
5,765

 
 
0

 
 
 
5,606

 
 
 
270

 
 
 
5,876

 
Total liabilities
 
$
12,911

 
 
$
0

 
 
 
$
5,606

 
 
 
$
7,337

 
 
 
$
12,943

 
(1) Excludes policy loans of $232 and equity method investments of $377, at carrying value

 
 
 
 
2017
(In millions)
Carrying
Value
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities held to maturity,
carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
21,331

 
 
$
26,491

 
 
 
$
0

 
 
 
$
0

 
 
 
$
26,491

 
Municipalities
 
357

 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
Mortgage and asset-backed
securities
 
26

 
 
0

 
 
 
8

 
 
 
19

 
 
 
27

 
Public utilities
 
3,300

 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
Sovereign and
supranational
 
1,523

 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
Banks/financial institutions
 
2,206

 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
Other corporate
 
2,687

 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
Other investments (1)
 
3,017

 
 
0

 
 
 
15

 
 
 
2,987

 
 
 
3,002

 
  Total assets
 
$
34,447

 
 
$
26,491

 
 
 
$
11,577

 
 
 
$
3,006

 
 
 
$
41,074

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other policyholders’ funds
 
$
6,939

 
 
$
0

 
 
 
$
0

 
 
 
$
6,841

 
 
 
$
6,841

 
Notes payable
(excluding capital leases)
 
5,267

 
 
0

 
 
 
5,288

 
 
 
265

 
 
 
5,553

 
Total liabilities
 
$
12,206

 
 
$
0

 
 
 
$
5,288

 
 
 
$
7,106

 
 
 
$
12,394

 

(1) Excludes policy loans of $210 and equity method investments of $118, at carrying value

Fair Value of Financial Instruments

Fixed maturity and equity securities

The Company determines the fair values of fixed maturity securities and public and privately-issued equity securities using the following approaches or techniques: price quotes and valuations from third party pricing vendors (including quoted market prices readily available from public exchange markets) and non-binding price quotes the Company obtains from outside brokers.

A third party pricing vendor has developed valuation models to determine fair values of privately issued securities to reflect the impact of the persistent economic environment and the changing regulatory framework. These models are discounted cash flow (DCF) valuation models, but also use information from related markets, specifically the CDS market to estimate expected cash flows. These models take into consideration any unique characteristics of the securities and make various adjustments to arrive at an appropriate issuer-specific loss adjusted credit curve. This credit curve is then used with the relevant recovery rates to estimate expected cash flows and modeling of additional features, including illiquidity adjustments, if necessary, to price the security by discounting those loss adjusted cash flows. In cases where a credit curve cannot be developed from the specific security features, the valuation methodology takes into consideration other market observable inputs, including: 1) the most appropriate comparable security(ies) of the issuer; 2) issuer-specific CDS spreads; 3) bonds or CDS spreads of comparable issuers with similar characteristics such as rating, geography, or sector; or 4) bond indices that are comparative in rating, industry, maturity and region.

The pricing data and market quotes the Company obtains from outside sources, including third party pricing services, are reviewed internally for reasonableness. If a fair value appears unreasonable, the Company will re-examine the inputs and assess the reasonableness of the pricing data with the vendor. Additionally, the Company may compare the inputs to relevant market indices and other performance measurements. Based on management's analysis, the valuation is confirmed or may be revised if there is evidence of a more appropriate estimate of fair value based on available market data. The Company has performed verification of the inputs and calculations in any valuation models to confirm that the valuations represent reasonable estimates of fair value.

The fixed maturity securities classified as Level 3 consist of securities with limited or no observable valuation inputs. For Level 3 securities, the Company estimates the fair value of these securities by obtaining non-binding broker quotes from a limited number of brokers. These brokers base their quotes on a combination of their knowledge of the current pricing environment and market conditions. The Company considers these inputs to be unobservable. The Company also considers a variety of significant valuation inputs in the valuation process, including forward exchange rates, yen swap rates, dollar swap rates, interest rate volatilities, credit spread data on specific issuers, assumed default and default recovery rates, and certain probability assumptions. In obtaining these valuation inputs, the Company has determined that certain pricing assumptions and data used by its pricing sources are difficult to validate or corroborate by the market and/or appear to be internally developed rather than observed in or corroborated by the market. The use of these unobservable valuation inputs causes more subjectivity in the valuation process for these securities.

For the periods presented, the Company has not adjusted the quotes or prices it obtains from the pricing services and brokers it uses.

The following tables present the pricing sources for the fair values of the Company's fixed maturity and equity securities as of December 31.
 
 
2018
(In millions)
 
Quoted Prices in Active Markets for Identical Assets
(Level 1)
 
Significant Observable Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
32,993

 
 
 
$
1,349

 
 
 
$
0

 
 
 
$
34,342

 
               Total government and agencies
 
 
32,993

 
 
 
1,349

 
 
 
0

 
 
 
34,342

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
               Total municipalities
 
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
162

 
 
 
0

 
 
 
162

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
177

 
 
 
177

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
162

 
 
 
177

 
 
 
339

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
7,062

 
 
 
0

 
 
 
7,062

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
109

 
 
 
109

 
               Total public utilities
 
 
0

 
 
 
7,062

 
 
 
109

 
 
 
7,171

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
               Total sovereign and supranational
 
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8,895

 
 
 
0

 
 
 
8,895

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
23

 
 
 
23

 
               Total banks/financial institutions
 
 
0

 
 
 
8,895

 
 
 
23

 
 
 
8,918

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
28,789

 
 
 
0

 
 
 
28,789

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
213

 
 
 
213

 
               Total other corporate
 
 
0

 
 
 
28,789

 
 
 
213

 
 
 
29,002

 
                  Total securities available for sale
 
 
$
32,993

 
 
 
$
49,380

 
 
 
$
522

 
 
 
$
82,895

(1) 
Equity securities, carried at fair value: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
874

 
 
 
$
67

 
 
 
$
0

 
 
 
$
941

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
46

 
 
 
46

 
               Total equity securities
 
 
$
874

 
 
 
$
67

 
 
 
$
46

 
 
 
$
987

(1) 

(1) Includes perpetual securities

 
 
2018
(In millions)
 
Quoted Prices in Active Markets for Identical Assets
(Level 1)
 
Significant Observable Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
27,030

 
 
 
$
8

 
 
 
$
0

 
 
 
$
27,038

 
               Total government and agencies
 
 
27,030

 
 
 
8

 
 
 
0

 
 
 
27,038

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
               Total municipalities
 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Broker/other
 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
               Total public utilities
 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
               Total sovereign and supranational
 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
               Total banks/financial institutions
 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
               Total other corporate
 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
                  Total securities held to maturity
 
 
$
27,030

 
 
 
$
9,677

 
 
 
$
15

 
 
 
$
36,722

 

 
 
2017
(In millions)
 
Quoted Prices in Active Markets
for Identical Assets
(Level 1)
 
Significant Observable
Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
30,109

 
 
 
$
1,121

 
 
 
$
0

 
 
 
$
31,230

 
               Total government and agencies
 
 
30,109

 
 
 
1,121

 
 
 
0

 
 
 
31,230

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
               Total municipalities
 
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
269

 
 
 
0

 
 
 
269

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
175

 
 
 
175

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
269

 
 
 
175

 
 
 
444

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
7,886

 
 
 
0

 
 
 
7,886

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
68

 
 
 
68

 
               Total public utilities
 
 
0

 
 
 
7,886

 
 
 
68

 
 
 
7,954

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,807

 
 
 
0

 
 
 
1,807

 
            Broker/other
 
 
0

 
 
 
102

 
 
 
0

 
 
 
102

 
               Total sovereign and supranational
 
 
0

 
 
 
1,909

 
 
 
0

 
 
 
1,909

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8,908

 
 
 
0

 
 
 
8,908

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
25

 
 
 
25

 
               Total banks/financial institutions
 
 
0

 
 
 
8,908

 
 
 
25

 
 
 
8,933

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
32,327

 
 
 
0

 
 
 
32,327

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
146

 
 
 
146

 
               Total other corporate
 
 
0

 
 
 
32,327

 
 
 
146

 
 
 
32,473

 
                  Total securities available for sale
 
 
$
30,109

 
 
 
$
53,790

 
 
 
$
414

 
 
 
$
84,313

(1) 
Equity securities, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
1,001

 
 
 
$
6

 
 
 
$
0

 
 
 
$
1,007

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
16

 
 
 
16

 
               Total equity securities
 
 
$
1,001

 
 
 
$
6

 
 
 
$
16

 
 
 
$
1,023

 

(1) Includes perpetual securities

 
 
2017
(In millions)
 
Quoted Prices in Active Markets
for Identical Assets
(Level 1)
 
Significant Observable
Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
26,491

 
 
 
$
0

 
 
 
$
0

 
 
 
$
26,491

 
               Total government and agencies
 
 
26,491

 
 
 
0

 
 
 
0

 
 
 
26,491

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
               Total municipalities
 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8

 
 
 
0

 
 
 
8

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
19

 
 
 
19

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
8

 
 
 
19

 
 
 
27

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
               Total public utilities
 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
               Total sovereign and supranational
 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
               Total banks/financial institutions
 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
               Total other corporate
 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
                  Total securities held to maturity
 
 
$
26,491

 
 
 
$
11,562

 
 
 
$
19

 
 
 
$
38,072

 


The following is a discussion of the determination of fair value of the Company's remaining financial instruments.

Derivatives

The Company uses derivative instruments to manage the risk associated with certain assets. However, the derivative instrument may not be classified in the same fair value hierarchy level as the associated asset. The Company uses pricing models to determine the estimated fair value of derivatives. Inputs used to value derivatives include, but are not limited to, interest rates, credit spreads, foreign currency forward and spot rates, and interest volatility. The significant inputs to pricing derivatives are generally observable in the market or can be derived by observable market data. When these inputs are observable, the derivatives are classified as Level 2.

The fair values of the foreign currency forwards and options associated with certain investments; the foreign currency forwards and options used to hedge foreign exchange risk from the Company's net investment in Aflac Japan and economically hedge certain portions of forecasted cash flows denominated in yen; and the foreign currency swaps associated with certain senior notes are based on the amounts the Company would expect to receive or pay. The determination of the fair value of these derivatives is based on observable market inputs, therefore they are classified as Level 2.

To determine the fair value of its interest rate derivatives, the Company uses inputs that are generally observable in the market or can be derived from observable market data. Interest rate swaps are cleared trades. In a cleared swap contract the clearinghouse provides benefits to the counterparties similar to contracts listed for investment traded on an exchange since it maintains a daily margin to mitigate counterparties credit risk. These derivatives are priced using
observable inputs, accordingly, they are classified as Level 2. For its interest rate swaptions, the Company estimates their fair values using observable market data, including interest rate curves and volatilities. Their fair values are also classified as Level 2.
For derivatives associated with VIEs where the Company is the primary beneficiary, the Company is not the direct counterparty to the swap contracts. As a result, the fair value measurements incorporate the credit risk of the collateral associated with the VIE. The Company receives valuations from a third party pricing vendor for these derivatives. Based on an analysis of these derivatives and a review of the methodology employed by the pricing vendor, the Company determined that due to the long duration of these swaps and the need to extrapolate from short-term observable data to derive and measure long-term inputs, certain inputs, assumptions and judgments are required to value future cash flows that cannot be corroborated by current inputs or current observable market data. As a result, the derivatives associated with the Company's consolidated VIEs are classified as Level 3 of the fair value hierarchy.

Other investments

Other investments where fair value is disclosed above include short-term investments and loan receivables. Loan receivables include transitional real estate loans, commercial mortgage loans, and middle market loans. The Company's loan receivables do not have readily determinable market prices and generally lack market liquidity. Fair values for loan receivables are determined based on the present value of expected future cash flows discounted at the applicable U.S. Treasury or London Interbank Offered Rate (LIBOR) yield plus an appropriate spread that considers other risk factors, such as credit and liquidity risk. These spreads are provided by the applicable asset managers based on their knowledge of the current loan pricing environment and market conditions. The spreads are a significant component of the pricing inputs and are generally considered unobservable. Therefore, these investments have been assigned a Level 3 within the fair value hierarchy.

Other policyholders' funds

The largest component of the other policyholders' funds liability is the Company's annuity line of business in Aflac Japan. The Company's annuities have fixed benefits and premiums. For this product, the Company estimates the fair value to be equal to the cash surrender value. This is analogous to the value paid to policyholders on the valuation date if they were to surrender their policy. The Company periodically checks the cash value against discounted cash flow projections for reasonableness. The Company considers its inputs for this valuation to be unobservable and have accordingly classified this valuation as Level 3.

Notes payable

The fair values of the Company's publicly issued notes payable are determined by utilizing available sources of observable inputs from third party pricing vendors and are classified as Level 2. The fair values of the Company's yen-denominated loans approximate their carrying values and are classified as Level 3.Transfers between Hierarchy Levels and Level 3 Rollforward

There were no transfers between Level 1 and 2 for assets and liabilities that are measured and carried at fair value on a recurring basis for the years ended December 31, 2018 and 2017, respectively.

The following tables present the changes in fair value of the Company's investments and derivatives carried at fair value classified as Level 3 as of December 31.
2018
 
 
Fixed Maturity Securities
 
Equity
Securities
 
Derivatives(1)
 
 
 
(In millions)
Mortgage-
and
Asset-
Backed
Securities
 
Public
Utilities
 
Banks/
Financial
Institutions
 
Other
Corporate
 
 
 
Foreign
Currency
Swaps
 
Credit
Default
Swaps
 
Total
 
Balance, beginning of period
$
175

 
$
68

 
$
25

 
$
146

 
$
16

 
$
22

 
$
1

 
$
453

 
Realized investment gains (losses) included
in earnings
0

 
0

 
0

 
0

 
(1
)
 
54

 
(1
)
 
52

 
Unrealized gains (losses) included in other
comprehensive income (loss)
2

 
1

 
(2
)
 
1

 
0

 
4

 
0

 
6

 
Purchases, issuances, sales and settlements:
 
 
 
 
 
 
 
 
 
 

 

 

 
Purchases
0

 
40

 
0

 
56

 
31

 
0

 
0

 
127

 
Issuances
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Sales
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Settlements
0

 
0

 
0

 
(6
)
 
0

 
0

 
0

 
(6
)
 
Transfers into Level 3
0

 
0

 
0

 
16

 
0

 
0

 
0

 
16

 
Transfers out of Level 3
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Balance, end of period
$
177

 
$
109

 
$
23

 
$
213

 
$
46

 
$
80

 
$
0

 
$
648

 
Changes in unrealized gains (losses) relating
to Level 3 assets and liabilities still held at
the end of the period included in realized
investment gains (losses)
$
0

 
$
0

 
$
0

 
$
0

 
$
(1
)
 
$
54

 
$
(1
)
 
$
52

 

(1) Derivative assets and liabilities are presented net


2017
 
  
Fixed Maturity Securities
 
 
 
Equity
Securities
 
Derivatives(1)
 
  
 
(In millions)
Mortgage-
and
Asset-
Backed
Securities
 
Public
Utilities
 
Banks/
Financial
Institutions
 
Other
Corporate
 
 
 
Foreign
Currency
Swaps
 
Credit
Default
Swaps
 
Total
 
Balance, beginning of period
$
198

 
$
16

 
$
25

 
$
0

 
$
3

 
$
(21
)
 
$
2

 
$
223

 
Realized investment gains (losses) included in
earnings
0

 
0

 
0

 
0

 
0

 
43

 
(1
)
 
42

 
Unrealized gains (losses) included in other
comprehensive income (loss)
3

 
0

 
0

 
2

 
0

 
0

 
0

 
5

 
Purchases, issuances, sales and settlements:


 
 
 


 
 
 


 


 


 


 
Purchases
0

 
76

 
0

 
122

 
16

 
0

 
0

 
214

 
Issuances
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Sales
0

 
0

 
0

 
(2
)
 
(1
)
 
0

 
0

 
(3
)
 
Settlements
(26
)
 
0

 
0

 
0

 
0

 
0

 
0

 
(26
)
 
Transfers into Level 3
0

 
0

 
0

 
24

(2) 
0

 
0

 
0

 
24

 
Transfers out of Level 3
0

 
(24
)
(2) 
0

 
0

 
(2
)
(3) 
0

 
0

 
(26
)
 
Balance, end of period
$
175

 
$
68

 
$
25

 
$
146

 
$
16

 
$
22

 
$
1

 
$
453

 
Changes in unrealized gains (losses) relating
to Level 3 assets and liabilities still held at
the end of the period included in realized
investment gains (losses)
$
0

 
$
0

 
$
0

 
$
0

 
$
0

 
$
43

 
$
(1
)
 
$
42

 

(1) Derivative assets and liabilities are presented net
(2) Transfer due to sector classification change
(3) Transfer due to change in accounting methodLevel 3 Significant Unobservable Input Sensitivity

The following tables summarize the significant unobservable inputs used in the valuation of the Company's Level 3 investments and derivatives carried at fair value as of December 31. Included in the tables are the inputs or range of possible inputs that have an effect on the overall valuation of the financial instruments.
2018
(In millions)
 
Fair Value
 
Valuation Technique(s)
 
Unobservable Input
 
Range
(Weighted Average)
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
  Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
    Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
       Mortgage- and asset-backed securities
 
 
$
177

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Public utilities
 
 
109

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
       Banks/financial institutions
 
 
23

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Other corporate
 
 
213

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
  Equity securities
 
 
46

 
 
Net asset value
 
Offered quotes
 
N/A
(a) 
  Other assets:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
125

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
19 - 120 bps
 
 
 
 
57

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
            Total assets
 
 
$
750

 
 
 
 
 
 
 
 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
  Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
$
98

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
28 - 211 bps
 
 
 
 
4

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
            Total liabilities
 
 
$
102

 
 
 
 
 
 
 
 

(a) N/A represents securities where the Company receives unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs.
(b) Inputs derived from U.S. long-term rates to accommodate long maturity nature of the Company's swaps
(c) Inputs derived from Japan long-term rates to accommodate long maturity nature of the Company's swaps





2017
(In millions)
 
Fair Value
 
Valuation Technique(s)
 
Unobservable Input
 
Range
(Weighted Average)
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
  Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
    Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
       Mortgage- and asset-backed securities
 
 
$
175

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Public utilities
 
 
68

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
       Banks/financial institutions
 
 
25

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Other corporate
 
 
146

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
  Equity securities
 
 
16

 
 
Net asset value
 
Offered quotes
 
N/A
(a) 
  Other assets:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
80

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
9 - 90 bps
 
 
 
 
70

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
       Credit default swaps
 
 
1

 
 
Discounted cash flow
 
Base correlation
 
    46.33% - 49.65%
(d) 
 
 
 
 
 
 
 
 
CDS spreads
 
25 bps
 
 
 
 
 
 
 
 
 
Recovery rate
 
37.24%
 
            Total assets
 
 
$
581

 
 
 
 
 
 
 
 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
  Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
$
120

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
13 - 157 bps
 
 
 
 
8

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
            Total liabilities
 
 
$
128

 
 
 
 
 
 
 
 

(a) N/A represents securities where the Company receives unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs.
(b) Inputs derived from U.S. long-term rates to accommodate long maturity nature of the Company's swaps
(c) Inputs derived from Japan long-term rates to accommodate long maturity nature of the Company's swaps
(d) Range of base correlation for the Company's bespoke tranche for attachment and detachment points corresponding to market indicesThe following is a discussion of the significant unobservable inputs or valuation techniques used in determining the fair value of securities and derivatives classified as Level 3.

Net Asset Value

The Company holds certain unlisted equity securities whose fair value is derived based on the financial statements published by the investee. These securities do not trade on an active market and the valuations derived are dependent on the availability of timely financial reporting of the investee. Net asset value is an unobservable input in the determination of fair value of equity securities.

Offered Quotes

In circumstances where the Company's valuation model price is overridden because it implies a value that is not consistent with current market conditions, the Company will solicit bids from a limited number of brokers. The Company also receives unadjusted prices from brokers for its mortgage and asset-backed securities. These quotes are non-binding but are reflective of valuation best estimates at that particular point in time. Offered quotes are an unobservable input in the determination of fair value of mortgage- and asset-backed securities, certain banks/financial institutions, certain other corporate, and equity securities investments.

Interest Rates and CDS Spreads

The significant drivers of the valuation of the interest and foreign exchange swaps are interest rates and CDS spreads. Some of the Company's swaps have long maturities that increase the sensitivity of the swaps to interest rate fluctuations. For the Company's foreign exchange or cross currency swaps that are in a net asset position, an increase in yen interest rates (all other factors held constant) will decrease the present value of the yen final settlement receivable (receive leg), thus decreasing the value of the swap as long as the derivative remains in a net asset position.
Foreign exchange swaps also have a lump-sum final settlement of foreign exchange principal amounts at the termination of the swap. Assuming all other factors are held constant, an increase in yen interest rates will decrease the receive leg and decrease the net value of the swap. Likewise, holding all other factors constant, an increase in U.S. dollar interest rates will increase the swap's net value due to the decrease in the present value of the dollar final settlement payable (pay leg).
The extinguisher feature in most of the Company's VIE swaps results in a cessation of cash flows and no further payments between the parties to the swap in the event of a default on the referenced or underlying collateral. To price this feature, the Company applies the survival probability of the referenced entity to the projected cash flows. The survival probability uses the CDS spreads and recovery rates to adjust the present value of the cash flows. For extinguisher swaps with positive values, an increase in CDS spreads decreases the likelihood of receiving the final exchange payments and reduces the value of the swap.

For additional information on the Company's investments and financial instruments, see the accompanying Notes 1, 3 and 4.
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES
 12 Months Ended
Dec. 31, 2018
Deferred Policy Acquisition Costs Disclosures [Abstract]  
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES
Consolidated policy acquisition costs deferred were $1.5 billion in 2018, compared with $1.5 billion in 2017 and $1.4 billion in 2016. The following table presents a rollforward of deferred policy acquisition costs by segment for the years ended December 31.
  
2018
 
2017
(In millions)
Japan
 
U.S.
 
Japan
 
U.S.
Deferred policy acquisition costs:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Balance, beginning of year
 
$
6,150

 
 
 
$
3,355

 
 
 
$
5,765

 
 
 
$
3,228

 
Capitalization
 
833

 
 
 
669

 
 
 
839

 
 
 
629

 
Amortization
 
(710
)
 
 
 
(534
)
 
 
 
(630
)
 
 
 
(502
)
 
Foreign currency translation and other
 
111

 
 
 
1

 
 
 
176

 
 
 
0

 
Balance, end of year
 
$
6,384

 
 
 
$
3,491

 
 
 
$
6,150

 
 
 
$
3,355

 

Commissions deferred as a percentage of total acquisition costs deferred were 72% in 2018, compared with 72% in 2017 and 74% in 2016.

Personnel, compensation and benefit expenses as a percentage of insurance expenses were 54% in 2018, compared with 56% in 2017 and 53% in 2016. Advertising expense, which is included in insurance expenses in the consolidated statements of earnings, was as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Advertising expense:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
108

 
 
 
$
100

 
 
 
$
100

 
Aflac U.S.
 
110

 
 
 
110

 
 
 
124

 
          Total advertising expense
 
$
218

 
 
 
$
210

 
 
 
$
224

 


Depreciation and other amortization expenses, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Depreciation expense
 
$
48

 
 
 
$
50

 
 
 
$
48

 
Other amortization expense
 
1

 
 
 
3

 
 
 
6

 
          Total depreciation and other amortization expense
 
$
49

 
 
 
$
53

 
 
 
$
54

 


Lease and rental expense, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Lease and rental expense:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
53

 
 
 
$
52

 
 
 
$
53

 
Aflac U.S.
 
16

 
 
 
21

 
 
 
21

 
Other
 
4

 
 
 
2

 
 
 
1

 
          Total lease and rental expense
 
$
73

 
 
 
$
75

 
 
 
$
75

 
v3.10.0.1
POLICY LIABILITIES
 12 Months Ended
Dec. 31, 2018
Insurance Loss Reserves [Abstract]  
POLICY LIABILITIES POLICY LIABILITIES
Policy liabilities consist of future policy benefits, unpaid policy claims, unearned premiums, and other policyholders' funds, which accounted for 84%, 4%, 5% and 7% of total policy liabilities at December 31, 2018, respectively. The Company regularly reviews the adequacy of its policy liabilities in total and by component.
The liability for future policy benefits as of December 31 consisted of the following:
  
  
 
Liability Amounts
 
 
Interest Rates
(In millions)
Policy
Issue Year
 
2018
 
2017
 
 
Year of
Issue
 
In 20
Years
Health insurance:
 
 
 
 
 
 
 
 
 
 
 
 
Japan:
1992 - 2018
 
$
11,598

 
$
10,167

 
 
1.0 - 2.5
%
 
1.0 - 2.5
%
 
1974 - 2013
 
1,161

 
1,133

 
 
2.7 - 2.75
 
 
2.25 - 2.75
 
 
1998 - 2018
 
12,764

 
12,386

 
 
3.0
 
 
3.0
 
 
1997 - 1999
 
2,452

 
2,454

 
 
3.5
 
 
3.5
 
 
1994 - 1996
 
3,056

 
3,046

 
 
4.0 - 4.5
 
 
4.0 - 4.5
 
 
1987 - 1994
 
14,722

 
14,829

 
 
5.5
 
 
5.5
 
 
1985 - 1991
 
1,779

 
1,816

 
 
5.25 - 6.75
 
 
5.25 - 5.5
 
 
1978 - 1984
 
1,964

 
2,037

 
 
6.5
 
 
5.5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S.:
2013 - 2018
 
96

 
82

 
 
3.0 - 3.5
 
 
3.0 - 3.5
 
 
2012 - 2018
 
1,682

 
1,366

 
 
3.75
 
 
3.75
 
 
2011
 
353

 
343

 
 
4.75
 
 
4.75
 
 
2005 - 2010
 
2,946

 
2,944

 
 
5.5
 
 
5.5
 
 
1988 - 2004
 
641

 
656

 
 
8.0
 
 
6.0
 
 
1986 - 2004
 
1,245

 
1,296

 
 
6.0
 
 
6.0
 
 
1981 - 1986
 
151

 
159

 
 
6.5 - 7.0
 
 
5.5 - 6.5
 
 
1998 - 2004
 
1,311

 
1,310

 
 
7.0
 
 
7.0
 
 
Other
 
17

 
18

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Intercompany eliminations:
2015
 
(583
)
(1) 
(609
)
(1) 
 
2.0
 
 
2.0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Life insurance:
 
 
 
 
 
 
 
 
 
 
 
 
Japan:
2001 - 2018
 
10,296

 
8,850

 
 
1.0 - 1.85
 
 
1.0 - 1.85
 
 
2011 - 2017
 
5,116

 
4,763

 
 
2.0
 
 
2.0
 
 
2009 - 2011
 
3,867

 
3,393

 
 
2.25
 
 
2.25
 
 
1992 - 2006
 
5

 
5

 
 
2.19
 
 
1.55
 
 
2005 - 2011
 
1,769

 
1,642

 
 
2.5
 
 
2.5
 
 
1985 - 2006
 
2,057

 
2,048

 
 
2.7
 
 
2.25
 
 
2007 - 2011
 
1,380

 
1,319

 
 
2.75
 
 
2.75
 
 
1999 - 2011
 
2,249

 
2,189

 
 
3.0
 
 
3.0
 
 
1996 - 2009
 
678

 
675

 
 
3.5
 
 
3.5
 
 
1994 - 1996
 
901

 
908

 
 
4.0 - 4.5
 
 
4.0 - 4.5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S.:
1956 - 2018
 
695

 
632

 
 
3.5 - 6.0
 
 
3.5 - 6.0
 
Total
 
 
$
86,368

 
$
81,857

 
 
 
 
 
 
 
(1) Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements

The weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits for Japanese policies were 3.3% in 2018, compared with 3.4% in 2017 and 3.5% in 2016; and for U.S. policies, 5.3% in 2018, compared with 5.4% in 2017 and 5.5% in 2016.

Changes in the liability for unpaid policy claims were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Unpaid supplemental health claims, beginning of period
 
$
3,884

 
 
 
$
3,707

 
 
 
$
3,548

 
Less reinsurance recoverables
 
30

 
 
 
27

 
 
 
26

 
Net balance, beginning of period
 
3,854

 
 
 
3,680

 
 
 
3,522

 
Add claims incurred during the period related to:
 
 
 
 
 
 
 
 
 
 
 
Current year
 
7,101

 
 
 
6,979

 
 
 
7,037

 
Prior years
 
(563
)
 
 
 
(518
)
 
 
 
(465
)
 
Total incurred
 
6,538

 
 
 
6,461

 
 
 
6,572

 
Less claims paid during the period on claims incurred during:
 
 
 
 
 
 
 
 
 
 
 
Current year
 
4,612

 
 
 
4,530

 
 
 
4,613

 
Prior years
 
1,898

 
 
 
1,822

 
 
 
1,865

 
Total paid
 
6,510

 
 
 
6,352

 
 
 
6,478

 
Effect of foreign exchange rate changes on unpaid claims
 
43

 
 
 
65

 
 
 
64

 
Net balance, end of period
 
3,925

 
 
 
3,854

 
 
 
3,680

 
Add reinsurance recoverables
 
27

 
 
 
30

 
 
 
27

 
Unpaid supplemental health claims, end of period
 
3,952

 
 
 
3,884

 
 
 
3,707

 
Unpaid life claims, end of period
 
632

 
 
 
508

 
 
 
338

 
Total liability for unpaid policy claims
 
$
4,584

 
 
 
$
4,392

 
 
 
$
4,045

 

The incurred claims development related to prior years reflects favorable claims experience compared to previous estimates. The favorable claims development of $563 million for 2018 comprises approximately $419 million from Japan, which represents approximately 74% of the total. Excluding the impact of foreign exchange of a gain of approximately $14 million from December 31, 2017 to December 31, 2018, the favorable claims development in Japan would have been approximately $404 million, representing approximately 72% of the total.

The Company has experienced continued favorable claim trends in 2018 for its core health products in Japan. The Company's experience in Japan related to the average length of stay in the hospital for cancer treatment has shown continued decline in the current period. In addition, cancer treatment patterns in Japan are continuing to be influenced by significant advances in early-detection techniques and by the increased use of pathological diagnosis rather than clinical exams. Additionally, follow-up radiation and chemotherapy treatments are occurring more often on an outpatient basis. Such changes in treatment not only increase the quality of life and initial outcomes for the patients, but also decrease the average length of each hospital stay, resulting in favorable claims development.

As of December 31, 2018 and 2017, unearned premiums consisted primarily of discounted advance premiums on deposit. Discounted advance premiums are premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period. These advanced premiums represented 69% of the December 31, 2018 and 73% of the December 31, 2017 unearned premiums balances.

As of December 31, 2018 and 2017, the largest component of the other policyholders' funds liability was the Company's annuity line of business in Aflac Japan. The Company's annuities have fixed benefits and premiums. These annuities represented 97% of other policyholders' funds liability at December 31, 2018, compared with 98% at December 31, 2017 .
v3.10.0.1
REINSURANCE
 12 Months Ended
Dec. 31, 2018
Reinsurance Disclosures [Abstract]  
REINSURANCE REINSURANCE

The Company periodically enters into fixed quota-share coinsurance agreements with other companies in the normal course of business. For each of its reinsurance agreements, the Company determines whether the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums and benefits are reported net of insurance ceded.

The Company has recorded a deferred profit liability related to reinsurance transactions. The remaining deferred profit liability of $1.0 billion, as of December 31, 2018, is included in future policy benefits in the consolidated balance sheet and is being amortized into income over the expected lives of the policies. The Company has also recorded a reinsurance recoverable for reinsurance transactions, which is included in other assets in the consolidated balance sheet and had a remaining balance of $941 million and $908 million as of December 31, 2018 and 2017, respectively. The increase in the reinsurance recoverable balance was driven by two aggregating factors: yen strengthening and the growth in reserves related to the business that has been reinsured as the policies age. The spot yen/dollar exchange rate strengthened by approximately 2% and ceded reserves increased approximately 2% from December 31, 2017, to December 31, 2018.

The following table reconciles direct premium income and direct benefits and claims to net amounts after the effect of reinsurance for the years ended December 31.
(In millions)
2018
2017
2016
Direct premium income
 
$
19,018

 
 
$
18,875

 
 
$
19,592

 
Ceded to other companies:
 
 
 
 
 
 
 
 
 
    Ceded Aflac Japan closed blocks
 
(497
)
 
 
(515
)
 
 
(560
)
 
    Other
 
(58
)
 
 
(51
)
 
 
(48
)
 
Assumed from other companies:
 
 
 
 
 
 
 
 
 
    Retrocession activities
 
208

 
 
216

 
 
234

 
    Other
 
6

 
 
6

 
 
7

 
Net premium income
 
$
18,677

 
 
$
18,531

 
 
$
19,225

 
 
 
 
 
 
 
 
 
 
 
Direct benefits and claims
 
$
12,293

 
 
$
12,486

 
 
$
13,240

 
Ceded benefits and change in reserves for future benefits:
 
 
 
 
 
 
 
 
 
    Ceded Aflac Japan closed blocks
 
(450
)
 
 
(473
)
 
 
(509
)
 
    Eliminations
 
43

 
 
51

 
 
58

 
    Other
 
(44
)
 
 
(44
)
 
 
(38
)
 
Assumed from other companies:
 
 
 
 
 
 
 
 
 
    Retrocession activities
 
209

 
 
209

 
 
222

 
    Eliminations
 
(53
)
 
 
(51
)
 
 
(58
)
 
    Other
 
2

 
 
3

 
 
4

 
Benefits and claims, net
 
$
12,000

 
 
$
12,181

 
 
$
12,919

 


These reinsurance transactions are indemnity reinsurance that do not relieve the Company from its obligations to policyholders. In the event that the reinsurer is unable to meet their obligations, the Company remains liable for the reinsured claims.

As a part of its capital contingency plan, the Company entered into a committed reinsurance facility agreement on December 1, 2015 in the amount of approximately 110 billion yen of reserves. This reinsurance facility agreement was renewed in 2018 and is effective until December 31, 2019. There are also additional commitment periods of a one-year duration each of which are automatically extended unless notification is received from the reinsurer within 60 days prior to the expiration. The reinsurer can withdraw from the committed facility if Aflac‘s Standard and Poor's (S&P) rating drops below BBB-. As of December 31, 2018, the Company had not executed a reinsurance treaty under this committed reinsurance facility.
v3.10.0.1
NOTES PAYABLE
 12 Months Ended
Dec. 31, 2018
Debt Disclosure [Abstract]  
NOTES PAYABLE NOTES PAYABLE
A summary of notes payable as of December 31 follows:
(In millions)
2018
 
2017
2.40% senior notes paid November 2018
 
$
0

 
 
 
$
548

 
4.00% senior notes due February 2022
 
348

 
 
 
348

 
3.625% senior notes due June 2023
 
698

 
 
 
697

 
3.625% senior notes due November 2024
 
746

 
 
 
745

 
3.25% senior notes due March 2025
 
447

 
 
 
446

 
2.875% senior notes due October 2026
 
297

 
 
 
297

 
6.90% senior notes due December 2039
 
220

 
 
 
220

 
6.45% senior notes due August 2040
 
254

 
 
 
254

 
4.00% senior notes due October 2046
 
394

 
 
 
394

 
4.750% senior notes due January 2049
 
540

 
 
 
0

 
Yen-denominated senior notes and subordinated debentures:
 
 
 
 
 
 
 
.932% senior notes due January 2027 (principal amount 60.0 billion yen)
 
538

 
 
 
528

 
1.159% senior notes due October 2030 (principal amount 29.3 billion yen)
 
262

 
 
 
0

 
1.488% senior notes due October 2033 (principal amount 15.2 billion yen)
 
136

 
 
 
0

 
1.750% senior notes due October 2038 (principal amount 8.9 billion yen)
 
79

 
 
 
0

 
2.108% subordinated debentures due October 2047 (principal amount 60.0 billion yen)
 
536

 
 
 
526

 
Yen-denominated loans:
 
 
 
 
 
 
 
Variable interest rate loan due September 2021 (.32% in 2018 and 2017, principal amount 5.0 billion yen)
 
45

 
 
 
44

 
Variable interest rate loan due September 2023 (.47% in 2018 and 2017, principal amount 25.0 billion yen)
 
225

 
 
 
220

 
Capitalized lease obligations payable through 2025
 
13

 
 
 
22

 
Total notes payable
 
$
5,778

 
 
 
$
5,289

 

Amounts in the table above are reported net of debt issuance costs and issuance premiums or discounts, if applicable, that are being amortized over the life of the notes.

In October 2018, the Parent Company issued $550 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 4.750% per annum, payable semi-annually, and have a 30-year maturity. These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.

In October 2018, the Parent Company issued three series of senior notes totaling 53.4 billion yen through a public debt offering under its U.S. shelf registration statement. The first series, which totaled 29.3 billion yen, bears interest at a fixed rate of 1.159% per annum, payable semi-annually, and has a 12-year maturity. The second series, which totaled 15.2 billion yen, bears interest at a fixed rate of 1.488% per annum, payable semi-annually, and has a 15-year maturity. The third series, which totaled 8.9 billion yen, bears interest at a fixed rate of 1.750% per annum, payable semi-annually, and has a 20-year maturity. These notes may only be redeemed before maturity, in whole but not in part, upon the occurrence of certain changes affecting U.S. taxation, as specified in the indenture governing the terms of the issuance.

In October 2017, the Parent Company issued 60.0 billion yen of subordinated debentures through a U.S. public debt offering. The debentures bear interest at an initial rate of 2.108% per annum through October 22, 2027, or earlier redemption. Thereafter, the rate of the interest of the debentures will be reset every five years at a rate of interest equal to the then-current JPY 5-year Swap Offered Rate plus 205 basis points. The debentures are payable semi-annually in arrears and have a 30-year maturity. The debentures are redeemable (i) at any time, in whole but not in part, upon the occurrence of certain tax events or certain rating agency events, as specified in the indenture governing the terms of the
debentures or (ii) on or after October 23, 2027, in whole or in part, at a redemption price equal to their principal amount plus accrued and unpaid interest to, but excluding, the date of redemption.

In January 2017, the Parent Company issued 60.0 billion yen of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of .932% per annum, payable semi-annually, and have a 10-year maturity. These notes may only be redeemed before maturity, in whole but not in part, upon the occurrence of certain changes affecting U.S. taxation, as specified in the indenture governing the terms of the issuance.

In September 2016, the Parent Company issued two series of senior notes totaling $700 million through a U.S. public debt offering. The first series, which totaled $300 million, bears interest at a fixed rate of 2.875% per annum, payable semi-annually and has a 10-year maturity. The second series, which totaled $400 million, bears interest at a fixed rate of 4.00% per annum, payable semi-annually, and has a 30-year maturity.

In September 2016, the Parent Company entered into two series of senior unsecured term loan facilities totaling 30.0 billion yen. The first series, which totaled 5.0 billion yen, bears an interest rate per annum equal to the Tokyo interbank market rate (TIBOR), or alternate TIBOR, if applicable, plus the applicable TIBOR margin and has a five-year maturity. The applicable margin ranges between .20% and .60%, depending on the Parent Company's debt ratings as of the date of determination. The second series, which totaled 25.0 billion yen, bears an interest rate per annum equal to TIBOR, or alternate TIBOR, if applicable, plus the applicable TIBOR margin and has a seven-year maturity. The applicable margin ranges between .35% and .75%, depending on the Parent Company's debt ratings as of the date of determination.

In March 2015, the Parent Company issued two series of senior notes totaling $1.0 billion through a U.S. public debt offering. The first series, which totaled $550 million, bore interest at a fixed rate of 2.40% per annum, payable semi-annually, and had a five-year maturity. The second series, which totaled $450 million, bears interest at a fixed rate of 3.25% per annum, payable semi-annually, and has a 10-year maturity. The Parent Company has entered into cross-currency swaps that convert the U.S. dollar-denominated principal and interest on the senior notes into yen-denominated obligations which results in lower nominal net interest rates on the debt. By entering into these cross-currency swaps, the Parent Company economically converted its $550 million liability into a 67.0 billion yen liability and reduced the interest rate on this debt from 2.40% in dollars to .24% in yen, and the Parent Company economically converted its $450 million liability into a 55.0 billion yen liability and reduced the interest rate on this debt from 3.25% in dollars to .82% in yen. In November 2018, the Parent Company used the net proceeds from the October 2018 issuance of its senior notes to redeem $550 million of the Parent Company's 2.40% senior notes due 2020.

In November 2014, the Parent Company issued $750 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 3.625% per annum, payable semi-annually, and have a 10-year maturity. These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date. The Parent Company entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes it issued into yen-denominated obligations. By entering into the swaps, the Parent Company economically converted its $750 million liability into an 85.3 billion yen liability and reduced the interest rate on this debt from 3.625% in dollars to 1.00% in yen.

In June 2013, the Parent Company issued $700 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 3.625% per annum, payable semi-annually, and have a 10-year maturity. These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date. The Parent Company had entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes it issued into yen-denominated obligations. By entering into these swaps, the Parent Company economically converted its $700 million liability into a 69.8 billion yen liability and reduced the interest rate on this debt from 3.625% in dollars to 1.50% in yen.

In February 2012, the Parent Company issued $350 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 4.00% per annum, payable semiannually, and have a 10-year maturity. These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the principal amount of the notes or (ii) the present value of the remaining scheduled payments of principal and interest to be redeemed, discounted to the redemption date, plus accrued and unpaid interest. The Parent Company entered into cross-currency interest rate swaps to reduce interest expense by converting the U.S. dollar-denominated principal and interest on the senior notes it issued into yen-denominated obligations. By entering into these swaps, the Parent Company economically converted its $350 million liability into a 27.0 billion yen liability and reduced the interest rate on this debt from 4.00% in dollars to 2.07% in yen.

In 2010 and 2009, the Parent Company issued senior notes through U.S. public debt offerings; the details of these notes are as follows. In August 2010, the Parent Company issued $450 million of senior notes that have a 30-year maturity. In December 2009, the Parent Company issued $400 million of senior notes that have a 30-year maturity. These senior notes pay interest semiannually and are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the principal amount of the notes or (ii) the present value of the remaining scheduled payments of principal and interest to be redeemed, discounted to the redemption date, plus accrued and unpaid interest. In December 2016, the Parent Company completed a tender offer in which it extinguished $176 million principal of its 6.90% senior notes due 2039 and $193 million principal of its 6.45% senior notes due 2040. The pretax loss due to the early redemption of these notes was $137 million.

For the Company's yen-denominated notes and loans, the principal amount as stated in dollar terms will fluctuate from period to period due to changes in the yen/dollar exchange rate. The Company has designated the majority of its yen-denominated notes payable as a nonderivative hedge of the foreign currency exposure of the Company's investment in Aflac Japan.

The aggregate contractual maturities of notes payable during each of the years after December 31, 2018, are as follows:
(In millions)
Long-term
Debt
 
Capitalized
Lease
Obligations
 
Total
Notes
Payable
2019
 
$
0

 
 
 
$
5

 
 
 
$
5

 
2020
 
0

 
 
 
3

 
 
 
3

 
2021
 
45

 
 
 
2

 
 
 
47

 
2022
 
350

 
 
 
1

 
 
 
351

 
2023
 
925

 
 
 
1

 
 
 
926

 
Thereafter
 
4,493

 
 
 
1

 
 
 
4,494

 
Total
 
$
5,813

 
 
 
$
13

 
 
 
$
5,826

 
A summary of the Company's lines of credit as of December 31, 2018 follows:
Borrower
Type
Original Term
Expiration Date
Capacity
Amount Outstanding
Interest Rate on Borrowed Amount
Maturity Period
Commitment Fee
Business Purpose
Aflac Incorporated
and Aflac
uncommitted bilateral
364 days
December 27, 2019
$100 million
$0 million
The rate quoted by the bank and agreed upon at the time of borrowing
Up to 3 months
None
General corporate purposes
Aflac Incorporated
unsecured revolving
3 years
March 31, 2019, or the date commitments are terminated pursuant to an event of default
100.0 billion yen
0.0 billion yen
A rate per annum equal to (a) Tokyo interbank market rate (TIBOR) plus, the alternative applicable TIBOR margin during the availability period from the closing date to the commitment termination date or (b) the TIBOR rate offered by the agent to major banks in yen for the applicable period plus, the applicable alternative TIBOR margin during the term out period
No later than
March 31, 2019
.30% to .50%, depending on the Parent Company's debt ratings as of the date of determination
General corporate purposes, including a capital contingency plan for the operations of the Parent Company
Aflac Incorporated
and Aflac
unsecured revolving
5 years
April 4, 2023, or the date commitments are terminated pursuant to an event of default
55.0 billion yen, or the equivalent amount in U.S. dollars
0.0 billion yen
A rate per annum equal to, at the Company's option, either, (a) London Interbank Offered Rate (LIBOR) adjusted for certain costs or (b) a base rate determined by reference to the highest of (1) the federal funds rate plus 1/2 of 1%, (2) the rate of interest for such day announced by Mizuho Bank, Ltd. as its prime rate, or (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin
No later than April 4, 2023
.085% to
.225%, depending on the Parent Company's debt ratings as of the date of determination
General corporate purposes, including a capital contingency plan for the operations of the Parent Company
Aflac Incorporated
and Aflac
uncommitted bilateral
None specified
None specified
$50 million
$0 million
A rate per annum equal to, at the Parent Company's option, either (a) a eurocurrency rate determined by reference to the agent's LIBOR for the interest period relevant to such borrowing or (b) the base rate determined by reference to the greater of (i) the prime rate as determined by the agent, and (ii) the sum of 0.50% and the federal funds rate for such day
Up to 3 months
None
General corporate purposes
Aflac(1)
uncommitted revolving
364 days
November 29, 2019
$250 million
$0 million
USD three-month LIBOR plus 75 basis points per annum
3 months
None
General corporate purposes
Aflac Incorporated(1)
uncommitted revolving
364 days
April 2, 2019
50.0 billion yen
0.0 billion yen
Three-month TIBOR plus 80 basis points per annum
3 months
None
General corporate purposes

(1) Intercompany credit agreement

The Parent Company was in compliance with all of the covenants of its notes payable and lines of credit at December 31, 2018. No events of default or defaults occurred during 2018 and 2017.
v3.10.0.1
INCOME TAXES
 12 Months Ended
Dec. 31, 2018
Income Tax Disclosure [Abstract]  
INCOME TAXES INCOME TAXES
The components of income tax expense (benefit) applicable to pretax earnings for the years ended December 31 were as follows:
(In millions)
Foreign
 
U.S.
 
Total
2018:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
771

 
 
 
$
608

 
 
 
$
1,379

 
Deferred
 
93

 
 
 
(409
)
 
 
 
(316
)
 
Total income tax expense
 
$
864

 
 
 
$
199

 
 
 
$
1,063

 
2017:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
722

 
 
 
$
(91
)
 
 
 
$
631

 
Deferred
 
(24
)
 
 
 
(1,193
)
 
 
 
(1,217
)
 
Total income tax expense
 
$
698

 
 
 
$
(1,284
)
 
 
 
$
(586
)
 
2016:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
650

 
 
 
$
234

 
 
 
$
884

 
Deferred
 
136

 
 
 
388

 
 
 
524

 
Total income tax expense
 
$
786

 
 
 
$
622

 
 
 
$
1,408

 


The Japan income tax rate for the fiscal year 2016 was 28.8%. The rate was reduced to 28.2% for the fiscal year 2017 and was further reduced to 28.0% for the fiscal year 2018.

For the United States, the Tax Cuts and Jobs Act (Tax Act) was signed into law on December 22, 2017. Effective January 1, 2018, the Tax Act imposed a broad number of changes in tax law, including the permanent reduction of the U.S. federal statutory corporate income tax rate from 35% to 21%.
In accordance with Staff Accounting Bulletin 118 (SAB 118) issued by the U.S. Securities and Exchange Commission in December 2017, the Company recorded provisional amounts for certain items for which the income tax accounting was not complete. As of the enactment date, the Company estimated provisional amounts for its deferred taxes, including related valuation allowance, resulting in a reduction of its deferred tax assets (DTAs) by approximately $1.0 billion and its deferred tax liabilities (DTLs) by $2.9 billion, for a net DTL reduction of approximately $1.9 billion. The provisions of ASC 740-10, Income Taxes, require that the effects of changes in tax law on deferred taxes be recognized as a component of the income tax provision in the period the tax rate change was enacted. Therefore, the $1.9 billion provisional amount of net DTL reduction was recorded in the fourth quarter of 2017 as a reduction in the “Income tax expense, Deferred” line item of the Company’s consolidated statement of earnings.

In 2018, the Company recorded additional income tax expense of $.4 million resulting from a decrease in the SAB 118 provisional estimate related to Japan deferred tax balances. No further adjustment was made to the SAB 118 provisional estimate related to the valuation allowance. As of December 31, 2018, the Company has completed its accounting for the Tax Act in accordance with SAB 118.

Income tax expense in the accompanying statements of earnings varies from the amount computed by applying the expected U.S. tax rate of 21% in 2018 and 35% in 2017 and 2016 to pretax earnings. The principal reasons for the differences and the related tax effects for the years ended December 31 were as follows:
(In millions)
2018
 
2017
 
2016
Income taxes based on U.S. statutory rates
 
$
836

 
 
 
$
1,406

 
 
 
$
1,424

 
Foreign rate differential
 
220


 

0

 
 
 
0

 
Write-down of U.S. deferred tax liabilities for tax reform change
 
0

 
 
 
(1,933
)
 
 
 
0

 
Utilization of foreign tax credit
 
(3
)
 
 
 
(27
)
 
 
 
(30
)
 
Nondeductible expenses
 
21

 
 
 
10

 
 
 
8

 
Other, net
 
(11
)
 
 
 
(42
)
 
 
 
6

 
Income tax expense
 
$
1,063

 
 
 
$
(586
)
 
 
 
$
1,408

 


Total income tax expense for the years ended December 31 was allocated as follows:
(In millions)
2018
 
2017
 
2016
Statements of earnings
 
$
1,063

 
 
 
$
(586
)
 
 
 
$
1,408

 
Other comprehensive income (loss):
 
 
 
 
 
 
 
 
 
 
 
Unrealized foreign currency translation gains (losses) during period
 
10

 
 
 
52

 
 
 
70

 
Unrealized gains (losses) on investment securities:
 
 
 
 
 
 
 
 
 
 
 
Unrealized holding gains (losses) on investment
securities during period
 
(787
)
 
 
 
575

 
 
 
962

 
Reclassification adjustment for realized (gains) losses
on investment securities included in net earnings
 
(12
)
 
 
 
1

 
 
 
18

 
Unrealized gains (losses) on derivatives during period
 
0

 
 
 
0

 
 
 
1

 
Pension liability adjustment during period
 
(8
)
 
 
 
3

 
 
 
(16
)
 
Total income tax expense (benefit) related to items of
other comprehensive income (loss)
 
(797
)
 
 
 
631

 
 
 
1,035

 
Additional paid-in capital (exercise of stock options)
 
0

 
 
 
0

 
 
 
(10
)
 
Total income taxes
 
$
266

 
 
 
$
45

 
 
 
$
2,433

 


The income tax effects of the temporary differences that gave rise to deferred income tax assets and liabilities as of December 31 were as follows:
(In millions)
2018
 
2017
Deferred income tax liabilities:
 
 
 
 
 
 
 
Deferred policy acquisition costs
 
$
3,404

 
 
 
$
3,285

 
Unrealized gains and other basis differences on investments
 
1,307

 
 
 
2,882

 
Premiums receivable
 
149

 
 
 
104

 
Policy benefit reserves
 
3,828

 
 
 
3,557

 
Total deferred income tax liabilities
 
8,688

 
 
 
9,828

 
Deferred income tax assets:
 
 
 
 
 
 
 
Unfunded retirement benefits
 
8

 
 
 
8

 
Other accrued expenses
 
40

 
 
 
141

 
Policy and contract claims
 
775

 
 
 
870

 
Foreign currency loss on Aflac Japan
 
38

 
 
 
67

 
Deferred compensation
 
163

 
 
 
155

 
Capital loss carryforwards
 
5

 
 
 
0

 
Depreciation
 
119

 
 
 
114

 
Anticipatory foreign tax credit
 
4,040

 
 
 
4,504

 
Deferred foreign tax credit
 
591

 
 
 
0

 
Other
 
150

 
 
 
57

 
Total deferred income tax assets before valuation allowance
 
5,929

 
 
 
5,916

 
Valuation allowance
 
(738
)
 
 
 
(657
)
 
Total deferred income tax assets after valuation allowance
 
5,191

 
 
 
5,259

 
Net deferred income tax liability
 
3,497

 
 
 
4,569

 
Current income tax liability
 
523

 
 
 
176

 
Total income tax liability
 
$
4,020

 
 
 
$
4,745

 

The application of U.S. GAAP requires the Company to evaluate the recoverability of deferred tax assets and establish a valuation allowance if necessary to reduce the deferred tax asset to an amount that is more likely than not expected to be realized. As noted above, the Company has determined a $577 million valuation allowance against its anticipatory foreign tax credit is necessary. The anticipatory foreign tax credit represents the foreign tax credit the Company will generate from the reversal of Japan deferred tax liabilities in the future. The Company has also determined a $161 million valuation allowance against its deferred foreign tax credits is necessary. Deferred foreign tax credits are foreign tax credits generated in the current tax year by the Japanese life company, but are unable to be utilized until 2019
due to Japan's current tax year not closing until March 31, 2019. Based upon a review of the Company's anticipated future taxable income, and including all other available evidence, both positive and negative, the Company's management has concluded that, notwithstanding the items noted above, it is more likely than not that all other deferred tax assets will be realized.

Under U.S. income tax rules, only 35% of non-life operating losses can be offset against life insurance taxable income each year. For current U.S. income tax purposes, as of December 31, 2018, there were non-life operating loss carryforwards of $21 million available to offset against future taxable income. The Company has capital loss carryforwards of $22 million available to offset capital gains, of which $4 million expires in 2021 and $18 million expires in 2023.

The Company files federal income tax returns in the United States and Japan as well as state or prefecture income tax returns in various jurisdictions in the two countries. The Company is currently under audit by the State of Georgia for tax years 2014-2016. There are currently no other open Federal, State, or local U.S. income tax audits. U.S. federal income tax returns for years before 2015 are no longer subject to examination. Japan corporate income tax returns for years before 2017 are no longer subject to examination. Management believes it has established adequate tax liabilities and final resolution of all open audits is not expected to have a material impact on the Company's consolidated financial statements.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows for the years ended December 31:
(In millions)
 
2018
 
 
2017
 
Balance, beginning of year
 
$
14


 
$
294


Additions for tax positions of prior years
 
1

  
 
0

  
Reductions for tax positions of prior years
 
0

  
 
(280
)
 
Balance, end of year
 
$
15


 
$
14




Included in the balance of the liability for unrecognized tax benefits at December 31, 2018, are $14 million of tax positions for which the ultimate deductibility is highly certain, but for which there is uncertainty about the timing of such deductibility, compared with $13 million at December 31, 2017. Because of the impact of deferred tax accounting, other than interest and penalties, the disallowance of the shorter deductibility period would not affect the annual effective tax rate, but would accelerate the payment of cash to the taxing authority to an earlier period. The Company has accrued approximately $1 million as of December 31, 2018, for permanent uncertainties, which if reversed would not have a material effect on the annual effective rate.

The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense. The Company recognized approximately $1 million in interest and penalties in 2018, compared with $1 million in 2017 and $13 million in 2016. The Company has accrued approximately $2 million for the payment of interest and penalties as of December 31, 2018, compared with $2 million a year ago.

As of December 31, 2018, there were no material uncertain tax positions for which the total amounts of unrecognized tax benefits will significantly increase or decrease within the next 12 months.
v3.10.0.1
SHAREHOLDERS' EQUITY
 12 Months Ended
Dec. 31, 2018
Stockholders' Equity Note [Abstract]  
SHAREHOLDERS' EQUITY SHAREHOLDERS' EQUITY
See Note 1 for a discussion of the stock split that occurred in March 2018. All share and per-share amounts have been adjusted to reflect the stock split for any of the periods presented.

The following table is a reconciliation of the number of shares of the Company's common stock for the years ended December 31.
(In thousands of shares)
2018
 
2017
 
2016
Common stock - issued:
 
 
 
 
 
Balance, beginning of period
1,345,762
 
1,342,498
 
1,339,446
Exercise of stock options and issuance of restricted shares
1,778
 
3,264
 
3,052
Balance, end of period
1,347,540
 
1,345,762
 
1,342,498
Treasury stock:
 
 
 
 
 
Balance, beginning of period
564,852
 
530,877
 
490,686
Purchases of treasury stock:
 
 
 
 
 
Open market
28,949
 
35,510
 
43,236
Other
392
 
1,018
 
662
Dispositions of treasury stock:
 
 
 
 
 
Shares issued to AFL Stock Plan
(1,306)
 
(1,782)
 
(2,130)
Exercise of stock options
(519)
 
(734)
 
(1,366)
Other
(114)
 
(37)
 
(211)
Balance, end of period
592,254
 
564,852
 
530,877
Shares outstanding, end of period
755,286
 
780,910
 
811,621

Outstanding share-based awards are excluded from the calculation of weighted-average shares used in the computation of basic EPS. The following table presents the approximate number of share-based awards to purchase shares, on a weighted-average basis, that were considered to be anti-dilutive and were excluded from the calculation of diluted earnings per share at December 31:
(In thousands)
2018
 
2017
 
2016
Anti-dilutive share-based awards
 
44

 
 
 
510

 
 
 
1,822

 

The weighted-average shares used in calculating earnings per share for the years ended December 31 were as follows: 
(In thousands of shares)
2018
 
2017
 
2016
Weighted-average outstanding shares used for calculating basic EPS
769,588

 
792,042

 
822,942

Dilutive effect of share-based awards
5,062

 
5,819

 
4,899

Weighted-average outstanding shares used for calculating diluted EPS
774,650

 
797,861

 
827,841



Share Repurchase Program: During 2018, the Company repurchased 28.9 million shares of its common stock in the open market, compared with 35.5 million shares in 2017 and 43.2 million shares in 2016. As of December 31, 2018, a remaining balance of 69.0 million shares of the Company's common stock was available for purchase under share repurchase authorizations by its board of directors.

Voting Rights: In accordance with the Parent Company's articles of incorporation, shares of common stock are generally entitled to one vote per share until they have been held by the same beneficial owner for a continuous period of 48 months, at which time they become entitled to 10 votes per share.
Reclassifications from Accumulated Other Comprehensive Income
The tables below are reconciliations of accumulated other comprehensive income by component for the years ended December 31.

Changes in Accumulated Other Comprehensive Income
2018
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension
Liability
Adjustment
 
Total
Balance, beginning of period
 
$
(1,750
)
 
 
 
$
5,964

 
 
 
$
(23
)
 
 
 
$
(163
)
 
 
 
$
4,028

 
Cumulative effect of change
in accounting principle -
financial instruments
 
0

 
 
 
(148
)
 
 
 
0

 
 
 
0

 
 
 
(148
)
 
Cumulative effect of change
in accounting principle -
tax effects from tax reform
 
(325
)
 
 
 
734

 
 
 
(3
)
 
 
 
(32
)
 
 
 
374

 
Other comprehensive
income (loss) before
reclassification
 
228

 
 
 
(2,350
)
 
 
 
2

 
 
 
(30
)
 
 
 
(2,150
)
 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
34

 
 
 
0

 
 
 
13

 
 
 
47

 
Net current-period other
comprehensive
income (loss)
 
228

 
 
 
(2,316
)
 
 
 
2

 
 
 
(17
)
 
 
 
(2,103
)
 
Balance, end of period
 
$
(1,847
)
 
 
 
$
4,234

 
 
 
$
(24
)
 
 
 
$
(212
)
 
 
 
$
2,151

 
All amounts in the table above are net of tax.
2017
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension Liability Adjustment
 
Total
Balance, beginning of period
 
$
(1,983
)
 
 
 
$
4,805

 
 
 
$
(24
)
 
 
 
$
(168
)
 
 
 
$
2,630

 
Other comprehensive
income (loss) before
reclassification
 
233

 
 
 
1,158

 
 
 
1

 
 
 
(6
)
 
 
 
1,386

 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
1

 
 
 
0

 
 
 
11

 
 
 
12

 
Net current-period other
comprehensive
income (loss)
 
233

 
 
 
1,159

 
 
 
1

 
 
 
5

 
 
 
1,398

 
Balance, end of period
 
$
(1,750
)
 
 
 
$
5,964

 
 
 
$
(23
)
 
 
 
$
(163
)
 
 
 
$
4,028

 
All amounts in the table above are net of tax.

2016
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension Liability Adjustment
 
Total
Balance, beginning of period
 
$
(2,196
)
 
 
 
$
2,986

 
 
 
$
(26
)
 
 
 
$
(139
)
 
 
 
$
625

 
Other comprehensive
income (loss) before
reclassification
 
213

 
 
 
1,854

 
 
 
2

 
 
 
(32
)
 
 
 
2,037

 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
(35
)
 
 
 
0

 
 
 
3

 
 
 
(32
)
 
Net current-period other
comprehensive
income (loss)
 
213

 
 
 
1,819

 
 
 
2

 
 
 
(29
)
 
 
 
2,005

 
Balance, end of period
 
$
(1,983
)
 
 
 
$
4,805

 
 
 
$
(24
)
 
 
 
$
(168
)
 
 
 
$
2,630

 
All amounts in the table above are net of tax.
For the year ended December 31, 2018, see Note 1 for discussion of the amounts reclassified between AOCI and retained earnings upon the adoption of new accounting pronouncements.

The tables below summarize the amounts reclassified from each component of accumulated other comprehensive income based on source for the years ended December 31.

Reclassifications Out of Accumulated Other Comprehensive Income
(In millions)
2018
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(63
)
 
Other-than-temporary impairment
losses realized
 
 
17

 
Other gains (losses)
 
 
(46
)
 
Total before tax
 
 
12

 
Tax (expense) or benefit(1)
 
 
$
(34
)
 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(18
)
 
Acquisition and operating expenses(2)
Prior service (cost) credit
 
0

 
Acquisition and operating expenses(2)
 
 
5

 
Tax (expense) or benefit(1)
 
 
$
(13
)
 
Net of tax
Total reclassifications for the period
 
$
(47
)
 
Net of tax

(1) Based on 27% blended tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see
Note 14 for additional details).
 
(In millions)
2017
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(29
)
 
Other-than-temporary impairment
losses realized
 
 
27

 
Other gains (losses)
 
 
(2
)
 
Total before tax
 
 
1

 
Tax (expense) or benefit(1)
 
 
$
(1
)
 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(17
)
 
Acquisition and operating expenses(2)
Prior service (cost) credit
 
0

 
Acquisition and operating expenses(2)
 
 
6

 
Tax (expense) or benefit(1)
 
 
$
(11
)
 
Net of tax
Total reclassifications for the period
 
$
(12
)
 
Net of tax
(1) Based on 35% tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).
(In millions)
2016
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(83
)
 
Other-than-temporary impairment
losses realized
 
 
136

 
Other gains (losses)
 
 
53

 
Total before tax
 
 
(18
)
 
Tax (expense) or benefit(1)
 
 
$
35

 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(15
)
 
Acquisition and operating expenses(2)
       Prior service (cost) credit
 
11

 
Acquisition and operating expenses(2)
 
 
1

 
Tax (expense) or benefit(1)
 
 
$
(3
)
 
Net of tax
Total reclassifications for the period
 
$
32

 
Net of tax
(1) Based on 35% tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).
v3.10.0.1
SHARE-BASED COMPENSATION
 12 Months Ended
Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
SHARE-BASED COMPENSATION SHARE-BASED COMPENSATION
See Note 1 for a discussion of the stock split that occurred in March 2018. All share and per-share amounts have been adjusted to reflect the stock split for any of the periods presented.
As of December 31, 2018, the Company has outstanding share-based awards under the Aflac Incorporated Long-Term Incentive Plan (the "Plan"). Share-based awards are designed to reward employees for their long-term contributions to the Company and provide incentives for them to remain with the Company. The number and frequency of share-based awards are based on competitive practices, operating results of the Company, government regulations, and other factors.
The Plan, as amended on February 14, 2017, allows for a maximum number of shares issuable over its term of 75 million shares including 38 million shares that may be awarded in respect of awards other than options or stock appreciation rights. If any awards granted under the Plan are forfeited or are terminated before being exercised or settled for any reason other than tax forfeiture, then the shares underlying the awards will again be available under the Plan.

The Plan allows awards to Company employees for incentive stock options (ISOs), non-qualifying stock options (NQSOs), restricted stock, restricted stock units, and stock appreciation rights. Non-employee directors are eligible for grants of NQSOs, restricted stock, and stock appreciation rights. As of December 31, 2018, approximately 40.3 million shares were available for future grants under this plan. The ISOs and NQSOs have a term of 10 years, and the share-based awards generally vest upon time-based conditions or time and performance-based conditions. Time-based vesting generally occurs after three years. Performance-based vesting conditions generally include the attainment of goals related to Company financial performance. As of December 31, 2018, the only performance-based awards issued and outstanding were restricted stock awards.

Stock options and stock appreciation rights granted under the amended Plan have an exercise price of at least the fair market value of the underlying stock on the grant date and have an expiration date no later than 10 years from the grant date. Time-based restricted stock awards, restricted stock units and stock options granted after January 1, 2017 generally vest on a ratable basis over three years, and awards granted prior to the amendment vest on a three-year cliff basis. The Compensation Committee of the Board of Directors has the discretion to determine vesting schedules.

Share-based awards granted to U.S.-based grantees are settled with authorized but unissued Company stock, while those issued to Japan-based grantees are settled with treasury shares.
Summary of Share-Based Compensation Expense

Share-based compensation expense consists primarily of expenses for stock options, restricted stock awards (including performance based restricted stock awards), and restricted stock units granted to employees.
The following table presents the impact of the expense recognized in connection with share-based awards for the periods ended December 31.
(In millions, except for per-share amounts)
2018
 
2017
 
2016
Impact on earnings from continuing operations
 
$
57

 
 
 
$
51

 
 
 
$
68

 
Impact on earnings before income taxes
 
57

 
 
 
51

 
 
 
68

 
Impact on net earnings
 
45

 
 
 
35

 
 
 
46

 
Impact on net earnings per share:
 
 
 
 
 
 
 
 
 
 
 
Basic
 
$
.06

 
 
 
$
.05

 
 
 
$
.06

 
Diluted
 
.06

 
 
 
.05

 
 
 
.06

 


Stock Options
The following table summarizes stock option activity under the employee stock option plan.
(In thousands of shares)
Stock
Option
Shares
 
Weighted-Average
Exercise Price
Per Share
Outstanding at December 31, 2015
 
15,836

 
 
 
$
25.47

 
Granted in 2016
 
1,328

 
 
 
30.70

 
Canceled in 2016
 
(362
)
 
 
 
27.82

 
Exercised in 2016
 
(4,122
)
 
 
 
24.46

 
Outstanding at December 31, 2016
 
12,680

 
 
 
26.28

 
Granted in 2017
 
626

 
 
 
35.80

 
Canceled in 2017
 
(236
)
 
 
 
24.95

 
Exercised in 2017
 
(5,766
)
 
 
 
30.11

 
Outstanding at December 31, 2017
 
7,304

 
 
 
28.03

 
Granted in 2018
 
67

 
 
 
44.59

 
Canceled in 2018
 
(167
)
 
 
 
32.11

 
Exercised in 2018
 
(1,874
)
 
 
 
26.78

 
Outstanding at December 31, 2018
 
5,330

 
 
 
$
28.54

 


(In thousands of shares)
2018
 
2017
 
2016
Shares exercisable, end of year
 
3,917

 
 
 
4,208

 
 
 
8,986

 


The Company estimates the fair value of each stock option granted using the Black-Scholes-Merton multiple option approach. Expected volatility is based on historical periods generally commensurate with the estimated terms of the options. The Company uses historical data to estimate option exercise and termination patterns within the model. Separate groups of employees that have similar historical exercise patterns are stratified and considered separately for valuation purposes. The expected term of options granted is derived from the output of the Company's option model and represents the weighted-average period of time that options granted are expected to be outstanding. The Company bases the risk-free interest rate on the Treasury note rate with a term comparable to that of the estimated term of the options. The weighted-average fair value of options at their grant date was $8.81 per share for 2018, compared with $7.64 for 2017 and $6.35 in 2016. The following table presents the assumptions used in valuing options granted during the years ended December 31.
 
2018
 
2017
 
2016
Expected term (years)
 
7.0
 
 
 
5.9
 
 
 
6.4
 
Expected volatility
 
22.0
%
 
 
26.0
%
 
 
27.0
%
Annual forfeiture rate
 
3.6
 
 
 
3.4
 
 
 
3.2
 
Risk-free interest rate
 
2.5
 
 
 
2.5
 
 
 
2.2
 
Dividend yield
 
2.4
 
 
 
2.5
 
 
 
2.9
 


The following table summarizes information about stock options outstanding and exercisable at December 31, 2018.
(In thousands of shares)
 
 
Options Outstanding
 
Options Exercisable
 
Range of
Exercise Prices
Per Share
 
 
Stock Option
Shares
Outstanding
 
Wgtd.-Avg.
Remaining
Contractual
Life (Yrs.)
 
Wgtd.-Avg.
Exercise
Price
Per Share
 
Stock Option
Shares
Exercisable
 
Wgtd.-Avg.
Exercise
Price
Per Share
 
$
11.07

-
$
24.28

 
 
 
1,181

 
 
 
1.8
 
 
 
$
20.76

 
 
 
1,181

 
 
 
$
20.76

 
 
24.75

-
28.97

 
 
 
1,718

 
 
 
4.8
 
 
 
27.76

 
 
 
1,026

 
 
 
26.95

 
 
29.04

-
31.21

 
 
 
1,226

 
 
 
5.8
 
 
 
30.77

 
 
 
1,221

 
 
 
30.77

 
 
31.22

-
37.22

 
 
 
1,134

 
 
 
7.5
 
 
 
34.44

 
 
 
488

 
 
 
33.86

 
 
38.76

-
44.59

 
 
 
71

 
 
 
9.3
 
 
 
44.21

 
 
 
1

 
 
 
38.76

 
 
$
11.07

-
$
44.59

 
 
 
5,330

 
 
 
5.0
 
 
 
$
28.54

 
 
 
3,917

 
 
 
$
27.14

 


The aggregate intrinsic value in the following table represents the total pretax intrinsic value, and is based on the difference between the exercise price of the stock options and the quoted closing common stock price of $45.56 as of December 31, 2018, for those awards that have an exercise price currently below the closing price. As of December 31, 2018, the aggregate intrinsic value of stock options outstanding was $91 million, with a weighted-average remaining term of 5.0 years. The total number of in-the-money stock options exercisable as of December 31, 2018, was 3.9 million. The aggregate intrinsic value of stock options exercisable at that same date was $72 million, with a weighted-average remaining term of 4.1 years.

The following table summarizes stock option activity during the years ended December 31.
(In millions)
2018
 
2017
 
2016
Total intrinsic value of options exercised
 
$
34

 
 
 
$
87

 
 
 
$
41

 
Cash received from options exercised
 
48

 
 
 
58

 
 
 
68

 
Tax benefit realized as a result of options exercised and
restricted stock releases
 
25

 
 
 
74

 
 
 
45

 


Performance-Based Restricted Stock Awards

Under the Plan, the Company grants selected executive officers performance-based restricted stock awards (PBRS) each February whose vesting is contingent upon meeting various performance goals. PBRS are generally granted at-the-money and contingently cliff vest over a period of three years, generally subject to continued employment. In February
2018, the Company granted 432 thousand performance-based stock awards, which are contingent on the achievement of the Company's financial performance metrics and its market-based conditions. On the date of grant, the Company estimated the fair value of restricted stock awards with market-based conditions using a Monte Carlo simulation model. The model discounts the value of the stock at the assumed vesting date based on a risk-free interest rate. Based on estimates of actual performance versus the vesting thresholds, the calculated fair value percentage pay-out estimate will be updated each quarter. Actual performance, including modification for relative total shareholder return, may result in the ultimate award of 0% to 200% percent of the initial number of PBRS issued, with the potential for no award if company performance goals are not achieved during the three-year period. PBRS subject to accelerated vesting at the date of retirement eligibility is recognized over the implicit service period.

The Company uses third-party analyses to assist in developing the assumptions used in, as well as calibrating, a Monte Carlo simulation model. The Company is responsible for determining the assumptions used in estimating the fair value of its share-based payment awards.

Key assumptions used to value PBRS granted during 2018 follows:
(In millions)
2018
 
Expected volatility (based on Aflac Inc. and peer group historical daily stock price)
 
16.48
%
 
 
Expected life from grant date (years)
 
2.9

 
 
Risk-free interest rate (based on U.S. Treasury yields at the date of grant)
 
2.29
%
 
 

Restricted Stock Awards and Units
The value of restricted stock awards and restricted stock units is based on the fair market value of our common stock at the date of grant. The following table summarizes restricted stock activity during the years ended December 31. 
(In thousands of shares)
Shares
 
Weighted-Average
Grant-Date
Fair Value
Per  Share
Restricted stock at December 31, 2015
 
3,630

 
 
 
$
29.21

 
Granted in 2016
 
1,756

 
 
 
30.84

 
Canceled in 2016
 
(152
)
 
 
 
30.33

 
Vested in 2016
 
(1,498
)
 
 
 
26.84

 
Restricted stock at December 31, 2016
 
3,736

 
 
 
30.88

 
Granted in 2017
 
1,118

 
 
 
36.48

 
Canceled in 2017
 
(202
)
 
 
 
32.23

 
Vested in 2017
 
(1,018
)
 
 
 
31.09

 
Restricted stock at December 31, 2017
 
3,634

 
 
 
32.40

 
Granted in 2018
 
1,121

 
 
 
44.27

 
Canceled in 2018
 
(105
)
 
 
 
34.39

 
Vested in 2018
 
(1,243
)
 
 
 
31.64

 
Restricted stock at December 31, 2018
 
3,407

 
 
 
$
36.52

 


As of December 31, 2018, total compensation cost not yet recognized in the Company's financial statements related to restricted stock awards and restricted stock units was $36 million, of which $15 million (799 thousand shares) was related to restricted stock awards with a performance-based vesting condition. The Company expects to recognize these amounts over a weighted-average period of approximately 1.0 year. There are no other contractual terms covering restricted stock awards once vested.
v3.10.0.1
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS
 12 Months Ended
Dec. 31, 2018
Insurance [Abstract]  
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS
The Company's insurance subsidiaries are required to report their results of operations and financial position to insurance regulatory authorities on the basis of statutory accounting practices prescribed or permitted by such authorities. Statutory accounting practices primarily differ from U.S. GAAP by charging policy acquisition costs to expense as incurred, establishing future policy benefit liabilities using different actuarial assumptions as well as valuing investments and certain assets and accounting for deferred taxes on a different basis.

Aflac reports statutory financial statements that are prepared on the basis of accounting practices prescribed or permitted by the Nebraska Department of Insurance (NDOI). The NDOI recognizes statutory accounting principles and practices prescribed or permitted by the state of Nebraska for determining and reporting the financial condition and results of operations of an insurance company, and for determining a company's solvency under Nebraska insurance law. The National Association of Insurance Commissioners' (NAIC) Accounting Practices and Procedures Manual (SAP) has been adopted by the state of Nebraska as a component of those prescribed or permitted practices. Additionally, the Director of the NDOI has the right to permit other specific practices which deviate from prescribed practices. Prior to the Japan branch conversion on April 1, 2018, Aflac had been given explicit permission by the Director of the NDOI for two such permitted practices. These permitted practices, which did not impact the calculation of net income on a statutory basis or prevent the triggering of a regulatory event in the Company's RBC calculation, were as follows:

•
Aflac reported as admitted assets the refundable lease deposits on the leases of commercial office space which house Aflac Japan's sales operations. These lease deposits are unique and part of the ordinary course of doing business in the country of Japan; these assets would be non-admitted under SAP.

•
Aflac entered into a reinsurance agreement effective March 31, 2015 with a then unauthorized reinsurer. The effective date of this agreement predated the effective date of Nebraska's Amended Credit for Reinsurance statute (44-416) allowing certified reinsurers and also predated the subsequent approval of the agreement's assuming reinsurer as a Certified Reinsurer, which occurred on August 30, 2015 and December 24, 2015, respectively. Aflac obtained a permitted practice to recognize this treaty and counterparty as a Certified Reinsurer for the purpose of determining the collateral required to receive reinsurance reserve credit.

On April 1, 2018, the Company entered into a series of transactions in order to complete the conversion of the Japan branch into a Japanese insurance corporation. As a result of the conversion, the permitted practices were no longer necessary, therefore they were canceled by the NDOI effective April 2, 2018. A reconciliation of Aflac's capital and surplus between SAP and practices permitted by the state of Nebraska is shown below for the years ended December 31:
(In millions)
2018
 
2017
Capital and surplus, Nebraska state basis
 
$
2,600

 
 
 
$
11,001

 
State Permitted Practice:
 
 
 
 
 
 
 
Refundable lease deposits – Japan
 
0

 
 
 
(43
)
 
Reinsurance - Japan
 
0

 
 
 
(818
)
 
Capital and surplus, NAIC basis
 
$
2,600

 
 
 
$
10,140

 


As of December 31, 2018, Aflac's capital and surplus significantly exceeded the required company action level capital and surplus of $.5 billion. As determined on a U.S. statutory accounting basis, Aflac's net income was $1.3 billion in 2018, $2.6 billion in 2017 and $2.8 billion in 2016.

Aflac Japan must report its results of operations and financial position to the Japanese Financial Services Agency (FSA) on a Japanese regulatory accounting basis as prescribed by the FSA. Capital and surplus of Aflac Japan, based on Japanese regulatory accounting practices, was $6.4 billion at December 31, 2018, compared with $6.7 billion at December 31, 2017. Japanese regulatory accounting practices differ in many respects from U.S. GAAP. Under Japanese regulatory accounting practices, policy acquisition costs are expensed immediately; policy benefit and claim reserving methods and assumptions are different; premium income is recognized on a cash basis; different consolidation criteria apply to VIEs; reinsurance is recognized on a different basis; and investments can have a separate accounting classification and treatment referred to as policy reserve matching bonds (PRM).

The Parent Company depends on its subsidiaries for cash flow, primarily in the form of dividends and management fees. Consolidated retained earnings in the accompanying financial statements largely represent the undistributed earnings of the Company's insurance subsidiary. Amounts available for dividends, management fees and other payments
to the Parent Company by its insurance subsidiaries may fluctuate due to different accounting methods required by regulatory authorities. These payments are also subject to various regulatory restrictions and approvals related to safeguarding the interests of insurance policyholders. Aflac must maintain adequate RBC for U.S. regulatory authorities, and Aflac Japan must maintain adequate solvency margins for Japanese regulatory authorities.

The maximum amount of dividends that can be paid to the Parent Company by Aflac without prior approval of Nebraska's director of insurance is the greater of the net income from operations, which excludes net realized investment gains, for the previous year determined under statutory accounting principles, or 10% of statutory capital and surplus as of the previous year-end. Dividends declared by Aflac during 2019 in excess of $1.3 billion would require such approval. Aflac declared dividends of $12.3 billion during 2018, including non-cash extraordinary dividends of $11.0 billion which represented the statutory book value of Aflac Japan on April 2, 2018.

After the Japan branch conversion as of April 1, 2018, Aflac Japan is required to meet certain financial criteria as governed by Japanese corporate law in order to provide dividends to the Parent Company. Under these criteria, dividend capacity at Aflac Japan is basically defined as retained earnings excluding capital reserves, which represent equity generated by capital profits that are statutorily required in Japan, less net after-tax unrealized losses on available-for-sale securities based on the previous fiscal year-end. Prior to April 1, 2018, a portion of Aflac Japan earnings, as determined on a Japanese regulatory accounting basis, could be remitted each year to Aflac U.S. after complying with solvency margin provisions and satisfying various conditions imposed by Japanese regulatory authorities for protecting policyholders. Profit remittances to the United States could fluctuate due to changes in the amounts of Japanese regulatory earnings. Among other items, factors affecting regulatory earnings include Japanese regulatory accounting practices and fluctuations in currency translation of Aflac Japan's U.S. dollar-denominated investments and related investment income into yen. Profits remitted by Aflac Japan to the Parent Company, after April 1, 2018, and to Aflac U.S., prior to April 1, 2018, were as follows for the years ended December 31:
  
In Dollars
 
In Yen
(In millions of dollars and billions of yen)
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Profit remittances
 
$
808

 
 
 
$
1,150

 
 
 
$
1,286

 
 
 
89.7

 
 
 
129.3

 
 
 
138.5

 
v3.10.0.1
BENEFIT PLANS
 12 Months Ended
Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]  
BENEFIT PLANS
Pension and Other Postretirement Plans
The Company has funded defined benefit plans in Japan and the United States, however the U.S. plan was frozen to new participants effective October 1, 2013. The Company also maintains non-qualified, unfunded supplemental retirement plans that provide defined pension benefits in excess of limits imposed by federal tax law for certain Japanese, U.S. and former employees, however the U.S. plan was frozen to new participants effective January 1, 2015. U.S. employees who are not participants in the defined benefit plan receive a nonelective 401(k) employer contribution.

The Company provides certain health care benefits for eligible U.S. retired employees, their beneficiaries and covered dependents ("other postretirement benefits"). The health care plan is contributory and unfunded. Effective January 1, 2014, employees eligible for benefits included the following: (1) active employees whose age plus service, in years, equaled or exceeded 80 (rule of 80); (2) active employees who were age 55 or older and have met the 15 years of service requirement; (3) active employees who would meet the rule of 80 in the next five years; (4) active employees who were age 55 or older and who would meet the 15 years of service requirement within the next five years; and (5) current retirees. For certain employees and former employees, additional coverage is provided for all medical expenses for life.

Information with respect to the Company's benefit plans' assets and obligations as of December 31 was as follows:

 
 
Pension Benefits
 
Other
 
 
Japan
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
2017
 
2018
2017
 
2018
2017
Projected benefit obligation:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Benefit obligation, beginning of year
 
 
$
341

 
 
$
329

 
 
 
$
908

 
 
$
798

 
 
 
$
36

 
 
$
37

 
      Service cost
 
 
19

 
 
20

 
 
 
27

 
 
24

 
 
 
0

 
 
0

 
      Interest cost
 
 
7

 
 
6

 
 
 
31

 
 
40

 
 
 
1

 
 
1

 
      Actuarial (gain) loss
 
 
35

 
 
(10
)
 
 
 
(69
)
 
 
65

 
 
 
4

 
 
0

 
      Benefits and expenses paid
 
 
(11
)
 
 
(14
)
 
 
 
(22
)
 
 
(19
)
 
 
 
(4
)
 
 
(2
)
 
      Effect of foreign exchange
rate changes
 
 
5

 
 
10

 
 
 
0

 
 
0

 
 
 
0

 
 
0

 
               Benefit obligation, end of year
 
 
396

 
 
341

 
 
 
875

 
 
908

 
 
 
37

 
 
36

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Plan assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fair value of plan assets,
beginning of year
 
 
270

 
 
229

 
 
 
448

 
 
359

 
 
 
0

 
 
0

 
      Actual return on plan assets
 
 
(9
)
 
 
16

 
 
 
(30
)
 
 
61

 
 
 
0

 
 
0

 
      Employer contributions
 
 
34

 
 
32

 
 
 
69

 
 
47

 
 
 
4

 
 
2

 
      Benefits and expenses paid
 
 
(11
)
 
 
(14
)
 
 
 
(22
)
 
 
(19
)
 
 
 
(4
)
 
 
(2
)
 
      Effect of foreign exchange
rate changes
 
 
5

 
 
7

 
 
 
0

 
 
0

 
 
 
0

 
 
0

 
               Fair value of plan assets, end of year
 
 
289

 
 
270

 
 
 
465

 
 
448

 
 
 
0

 
 
0

 
Funded status of the plans(1)
 
 
$
(107
)
 
 
$
(71
)
 
 
 
$
(410
)
 
 
$
(460
)
 
 
 
$
(37
)
 
 
$
(36
)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Amounts recognized in accumulated other
comprehensive income:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Net actuarial (gain) loss
 
 
$
95

 
 
$
44

 
 
 
$
174

 
 
$
203

 
 
 
$
9

 
 
$
6

 
      Prior service (credit) cost
 
 
(2
)
 
 
(2
)
 
 
 
(4
)
 
 
(4
)
 
 
 
0

 
 
0

 
               Total included in accumulated
other comprehensive income
 
 
$
93

 
 
$
42

 
 
 
$
170

 
 
$
199

 
 
 
$
9

 
 
$
6

 
Accumulated benefit obligation
 
 
$
356

 
 
$
307

 
 
 
$
746

 
 
$
756

 
 
 
  N/A

(2) 
 
N/A

(2) 
(1) Recognized in other liabilities in the consolidated balance sheets
(2) Not applicable
 
Pension Benefits
 
Other
 
Japan
 
 
U.S.
 
 
Postretirement Benefits
 
2018
 
2017
 
2016
 
 
2018
 
2017
 
2016
 
 
2018
 
2017
 
2016
 
Weighted-average actuarial assumptions:
  
 
  
 
  
 
 
  
 
  
 
  
 
  
  
 
  
 
  
  
Discount rate - net periodic benefit cost
1.25
%
 
1.25
%
 
1.75
%
 
 
3.75
%
 
4.25
%
 
4.50
%
 
 
3.75
%
 
4.25
%
 
4.50
%
 
Discount rate - benefit obligations
1.25

 
1.25

 
1.25

 
 
4.25

 
3.75

 
4.25

 
  
4.25

 
3.75

 
4.25

  
Expected long-term return on plan assets
2.00

 
2.00

 
2.00

 
 
6.50

 
6.75

 
7.00

 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
Rate of compensation increase
N/A
(1) 
N/A
(1) 
N/A
(1) 
 
4.00

 
4.00

 
4.00

 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
Health care cost trend rates
N/A
(1) 
N/A
(1) 
N/A
(1) 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
  
7.40

(2) 
5.40

(2) 
5.20

(2) 
(1) Not applicable
(2)For the years 2018, 2017 and 2016, the health care cost trend rates are expected to trend down to 4.1% in 61 years, 4.5% in 77 years, and 4.5% in 74 years, respectively.
The Company determines its discount rate assumption for its pension retirement obligations based on indices for AA corporate bonds with an average duration of approximately 20 years for the Japan pension plans and 17 years for the U.S. pension plans, and determination of the U.S. pension plans discount rate utilizes the 85-year extrapolated yield
curve. In Japan, participant salary and future salary increases are not factors in determining pension benefit cost or the related pension benefit obligation.

The Company bases its assumption for the long-term rate of return on assets on historical trends (10-year or longer historical rates of return for the Japanese plan assets and 15-year historical rates of return for the U.S. plan assets), expected future market movement, as well as the portfolio mix of securities in the asset portfolio including, but not limited to, style, class and equity and fixed income allocations. In addition, the Company's consulting actuaries evaluate its assumptions for long-term rates of return under Actuarial Standards of Practice (ASOP). Under the ASOP, the actual portfolio type, mix and class is modeled to determine a best estimate of the long-term rate of return. The Company in turn use those results to further validate its own assumptions.

Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plan. A one-percentage point increase and decrease in assumed health care cost trend rates would have the following effects as of December 31, 2018:
(In millions)
 
 
 
 
One percentage point increase:
 
 
 
 
Increase in total service and interest costs
 
 
$
0

 
Increase in postretirement benefit obligation
 
 
1

 
 
 
 
 
 
One percentage point decrease:
 
 
 
 
Decrease in total service and interest costs
 
 
$
0

 
Decrease in postretirement benefit obligation
 
 
1

 

Components of Net Periodic Benefit Cost
Pension and other postretirement benefit expenses are included in acquisition and operating expenses in the consolidated statements of earnings, which includes $25 million, $35 million and $17 million of other components of net periodic pension cost and postretirement costs (other than services costs) for the years ended December 31, 2018, 2017 and 2016, respectively. Total net periodic benefit cost includes the following components:
 
 
Pension Benefits
 
Other
 
 
 
Japan
 
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Service cost
 
 
$
19

 
 
 
$
20

 
 
 
$
16

 
 
 
$
27

 
 
 
$
24

 
 
 
$
23

 
 
 
$
0

 
 
 
$
0

 
 
 
$
1

 
Interest cost
 
 
7

 
 
 
6

 
 
 
9

 
 
 
31

 
 
 
40

 
 
 
29

 
 
 
1

 
 
 
1

 
 
 
2

 
Expected return on plan
assets
 
 
(6
)
 
 
 
(5
)
 
 
 
(4
)
 
 
 
(26
)
 
 
 
(24
)
 
 
 
(23
)
 
 
 
0

 
 
 
0

 
 
 
0

 
Amortization of net actuarial
loss
 
 
1

 
 
 
2

 
 
 
1

 
 
 
16

 
 
 
14

 
 
 
13

 
 
 
1

 
 
 
1

 
 
 
1

 
Amortization of prior service
cost (credit)
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
(11
)
 
Net periodic (benefit) cost
 
 
$
21

 
 
 
$
23

 
 
 
$
22

 
 
 
$
48

 
 
 
$
54

 
 
 
$
42

 
 
 
$
2

 
 
 
$
2

 
 
 
$
(7
)
 


Changes in Accumulated Other Comprehensive Income
The following table summarizes the amounts recognized in other comprehensive loss (income) for the years ended December 31:
 
 
Pension Benefits
 
Other
 
 
Japan
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Net actuarial loss (gain)
 
 
$
52

 
 
 
$
(21
)
 
 
 
$
26

 
 
 
$
(13
)
 
 
 
$
28

 
 
 
$
27

 
 
 
$
4

 
 
 
$
0

 
 
 
$
(4
)
 
Amortization of net actuarial loss
 
 
(1
)
 
 
 
(2
)
 
 
 
(1
)
 
 
 
(16
)
 
 
 
(14
)
 
 
 
(13
)
 
 
 
(1
)
 
 
 
(1
)
 
 
 
(1
)
 
Amortization of prior
service cost
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
11

 
     Total
 
 
$
51

 
 
 
$
(23
)
 
 
 
$
25

 
 
 
$
(29
)
 
 
 
$
14

 
 
 
$
14

 
 
 
$
3

 
 
 
$
(1
)
 
 
 
$
6

 


No transition obligations arose during 2018, and the transition obligations amortized to expense were immaterial for the years ended December 31, 2018, 2017 and 2016. Amortization of actuarial losses to expense in 2019 is estimated to be $4 million for the Japanese plans, $11 million for the U.S. plans and $1 million for the other postretirement benefits plan. Amortization of prior service costs and credits and transition obligations for all plans is expected to be negligible in 2019.

Benefit Payments
The following table provides expected benefit payments, which reflect expected future service, as appropriate.
 
 
Pension Benefits
 
Other
(In millions)
 
Japan
U.S.
 
Postretirement Benefits
2019
 
 
$
12

 
 
$
25

 
 
 
$
3

 
2020
 
 
12

 
 
26

 
 
 
3

 
2021
 
 
12

 
 
27

 
 
 
4

 
2022
 
 
19

 
 
36

 
 
 
4

 
2023
 
 
15

 
 
34

 
 
 
4

 
2024-2028
 
 
89

 
 
199

 
 
 
17

 


Funding

The Company plans to make contributions of $33 million to the Japanese funded defined benefit plan and $10 million to the U.S. funded defined benefit plan in 2019. The funding policy for the Company's non-qualified supplemental defined benefit pension plans and other postretirement benefits plan is to contribute the amount of the benefit payments made during the year.

Plan Assets

The investment objective of the Company's Japanese and U.S. funded defined benefit plans is to preserve the purchasing power of the plan's assets and earn a reasonable inflation-adjusted rate of return over the long term. Furthermore, the Company seeks to accomplish these objectives in a manner that allows for the adequate funding of plan benefits and expenses. In order to achieve these objectives, the Company's goal is to maintain a conservative, well-diversified and balanced portfolio of high-quality equity, fixed-income and money market securities. As a part of its strategy, the Company has established strict policies covering quality, type and concentration of investment securities. For the Company's Japanese plan, these policies include limitations on investments in derivatives including futures, options and swaps, and low-liquidity investments such as real estate, venture capital investments, and privately issued securities. For the Company's U.S. plan, these policies prohibit investments in precious metals, limited partnerships, venture capital, and direct investments in real estate. The Company is also prohibited from trading on margin.

The plan fiduciaries for the Company's funded defined benefit plans have developed guidelines for asset allocations reflecting a percentage of total assets by asset class, which are reviewed on an annual basis. Asset allocation targets as of December 31, 2018 were as follows:
 
 
Japan Pension
 
U.S. Pension
Domestic equities
 
 
5
%
 
 
 
40
%
 
International equities
 
 
18

 
 
 
20

 
Fixed income securities
 
 
66

 
 
 
40

 
Other
 
 
11

 
 
 
0

 
     Total
 
 
100
%
 
 
 
100
%
 


The U.S. Pension Plan had $39 million in cash at December 31, 2018. The plan fiduciaries authorized investing a contribution made to the Plan in 2018 on a graduated basis over a period of time.

The following table presents the fair value of Aflac Japan's pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 2 in the fair value hierarchy.
(In millions)
2018
 
2017
Japan pension plan assets:
 
 
 
 
 
 
 
     Equities:
 
 
 
 
 
 
 
        Japanese equity securities
 
$
14

 
 
 
$
37

 
        International equity securities
 
50

 
 
 
50

 
     Fixed income securities:
 
 
 
 
 
 
 
        Japanese bonds
 
34

 
 
 
91

 
        International bonds
 
160

 
 
 
62

 
     Insurance contracts
 
31

 
 
 
30

 
        Total
 
$
289

 
 
 
$
270

 

The following table presents the fair value of Aflac U.S.'s pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 1 in the fair value hierarchy.
(In millions)
2018
 
2017
U.S. pension plan assets:
 
 
 
 
 
 
 
     Mutual funds:
 
 
 
 
 
 
 
        Large cap equity funds
 
$
120

 
 
 
$
124

 
        Mid cap equity funds
 
17

 
 
 
22

 
        Real estate equity funds
 
13

 
 
 
13

 
        International equity funds
 
92

 
 
 
108

 
        Fixed income bond funds
 
179

 
 
 
175

 
     Aflac Incorporated common stock
 
5

 
 
 
5

 
     Cash and cash equivalents
 
39

 
 
 
1

 
        Total
 
$
465

 
 
 
$
448

 


The fair values of the Company's pension plan investments categorized as Level 1, consisting of mutual funds and common stock, are based on quoted market prices for identical securities traded in active markets that are readily and regularly available to the Company. The fair values of the Company's pension plan investments classified as Level 2 are based on quoted prices for similar assets in markets that are not active, other inputs that are observable, such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks, and default rates, or other market-corroborated inputs.

401(k) Plan

The Company sponsors a 401(k) plan in which it matches a portion of U.S. employees' contributions. The plan provides for salary reduction contributions by employees and provides for matching contributions which, starting January 1, 2018, the Company increased to 100% of each employee's contributions which were not in excess of 4% of the employee's annual cash compensation as a result of tax reform. In 2017 and 2016, the plan provided for matching contributions by the Company of 50% of each employee's contributions which were not in excess of 6% of the employee's annual compensation. Also, as a result of U.S. tax reform legislation enacted in December 2017, the Company announced it would made a one-time contribution of $500 to the 401(k) plan to all employees active on December 31, 2017. This contribution was made by January 31, 2018. The Company also provides a nonelective contribution to the 401(k) plan of 2% of annual cash compensation for employees who opted out of the future benefits of the U. S. defined benefit plan and for new U. S. employees.

The 401(k) contributions by the Company, included in acquisition and operating expenses in the consolidated statements of earnings, were $18 million in 2018, $15 million in 2017 and $11 million in 2016. The plan trustee held approximately 2.7 million shares of the Company's common stock for plan participants at December 31, 2018.

Stock Bonus Plan

Aflac U.S. maintains a stock bonus plan for eligible U.S. sales associates. Plan participants receive shares of Aflac Incorporated common stock based on their new annualized premium sales and their first-year persistency of substantially all new insurance policies. The cost of this plan, which was capitalized as deferred policy acquisition costs, amounted to $31 million in 2018, 2017 and 2016.
v3.10.0.1
COMMITMENTS AND CONTINGENT LIABILITIES
 12 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
COMMITMENTS AND CONTINGENT LIABILITIES COMMITMENTS AND CONTINGENT LIABILITIES
The Company has two outsourcing agreements with a technology and consulting corporation. The first agreement provides mainframe computer operations, distributed mid-range server computer operations, and related support for Aflac Japan. It has a remaining term of four years and an aggregate remaining cost of 36.1 billion yen ($326 million using the December 31, 2018, exchange rate). The second agreement provides application maintenance and development services for Aflac Japan. It has a remaining term of five years and an aggregate remaining cost of 8.6 billion yen ($77 million using the December 31, 2018, exchange rate).

The Company has an outsourcing agreement with a management consulting and technology services company to provide application maintenance and development services for its Japanese operation. The agreement has a remaining term of three years with an aggregate remaining cost of 10.4 billion yen ($94 million using the December 31, 2018, exchange rate).

The Company has two outsourcing agreements with information technology and data services companies to provide application maintenance and development services for its Japanese operation. The first agreement has a remaining term of one year with an aggregate remaining cost of .6 billion yen ($5 million using the December 31, 2018, exchange rate). The second agreement has a remaining term of four years with an aggregate remaining cost of 5.8 billion yen ($52 million using the December 31, 2018, exchange rate).

The Company leases office space and equipment under agreements that expire in various years through 2028. Future minimum lease payments due under non-cancelable operating leases at December 31, 2018, were as follows:

(In millions)
 
2019
$
63

2020
47

2021
35

2022
31

2023
8

Thereafter
18

   Total future minimum lease payments
$
202




The Company is a defendant in various lawsuits considered to be in the normal course of business. Members of the Company's senior legal and financial management teams review litigation on a quarterly and annual basis. The final results of any litigation cannot be predicted with certainty. Although some of this litigation is pending in states where large punitive damages, bearing little relation to the actual damages sustained by plaintiffs, have been awarded in recent years, the Company believes the outcome of pending litigation will not have a material adverse effect on its financial position, results of operations, or cash flows.

See Note 3 of the Notes to the Consolidated Financial Statements for details on certain investment commitments.

Guaranty Fund Assessments

The United States insurance industry has a policyholder protection system that is monitored and regulated by state insurance departments. These life and health insurance guaranty associations are state entities (in all 50 states as well as Puerto Rico and the District of Columbia) created to protect policyholders of an insolvent insurance company. All insurance companies (with limited exceptions) licensed to sell life or health insurance in a state must be members of that state’s guaranty association. Under state guaranty association laws, certain insurance companies can be assessed (up to prescribed limits) for certain obligations to the policyholders and claimants of impaired or insolvent insurance companies that write the same line or similar lines of business.

In 2009, the Pennsylvania Insurance Commissioner placed long-term care insurer Penn Treaty Network America Insurance Company and its subsidiary American Network Insurance Company (collectively referred to as Penn Treaty), neither of which is affiliated with Aflac, in rehabilitation and petitioned a state court for approval to liquidate Penn Treaty. A final order of liquidation was granted by a recognized judicial authority on March 1, 2017, and as a result, Penn Treaty is in the process of liquidation. The Company estimated and recognized the impact of its share of guaranty fund assessments resulting from the liquidation using a discounted rate of 4.25%. The Company recognized a discounted liability for the assessments of $62 million (undiscounted $94 million), offset by discounted premium tax credits of $48 million (undiscounted $74 million), for a net $14 million impact to net income in the quarter ended March 31, 2017. The Company paid a majority of these assessments by March 31, 2018, and a majority of the tax credit will be realized over the next four years. The Company used the cost estimate provided as of the liquidation date by the National Organization of Life and Health Guaranty Associations (NOLHGA) to calculate its estimated assessments and tax credits. Other guaranty fund assessments for the years ended December 31, 2018, 2017, and 2016 were immaterial.
v3.10.0.1
UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA
 12 Months Ended
Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]  
UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA UNAUDITED CONSOLIDATED QUARTERLY FINANCIAL DATA

In management's opinion, the following quarterly financial information fairly presents the results of operations for such periods and is prepared on a basis consistent with the Company's annual audited financial statements.
 
(In millions, except for per-share amounts)
March 31,
2018
 
June 30,
2018
 
September 30,
2018
 
December 31,
2018
Net premium income
 
$
4,745

 
 
 
$
4,706

 
 
 
$
4,636

 
 
 
$
4,591

 
Net investment income
 
837

 
 
 
862

 
 
 
870

 
 
 
874

 
Realized investment gains (losses)
 
(134
)
 
 
 
3

 
 
 
56

 
 
 
(355
)
 
Other income (loss)
 
16

 
 
 
18

 
 
 
15

 
 
 
16

 
Total revenues
 
5,464

 
 
 
5,589

 
 
 
5,577

 
 
 
5,126

 
Total benefits and expenses
 
4,482

 
 
 
4,458

 
 
 
4,431

 
 
 
4,404

 
Earnings before income taxes
 
982

 
 
 
1,131

 
 
 
1,146

 
 
 
722

 
Total income tax
 
265

 
 
 
299

 
 
 
301

 
 
 
197

 
Net earnings
 
$
717

 
 
 
$
832

 
 
 
$
845

 
 
 
$
525

 
Net earnings per basic share
 
$
.92

 
 
 
$
1.08

 
 
 
$
1.10

 
 
 
$
.69

 
Net earnings per diluted share
 
.91

 
 
 
1.07

 
 
 
1.09

 
 
 
.69

 
Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(In millions, except for per-share amounts)
March 31,
2017
 
June 30,
2017
 
September 30,
2017
 
December 31,
2017
Net premium income
 
$
4,638

 
 
 
$
4,665

 
 
 
$
4,648

 
 
 
$
4,580

 
Net investment income
 
794

 
 
 
802

 
 
 
811

 
 
 
812

 
Realized investment gains (losses)
 
(140
)
 
 
 
(56
)
 
 
 
30

 
 
 
15

 
Other income (loss)
 
17

 
 
 
17

 
 
 
17

 
 
 
17

 
Total revenues
 
5,309

 
 
 
5,428

 
 
 
5,506

 
 
 
5,424

 
Total benefits and expenses
 
4,411

 
 
 
4,383

 
 
 
4,431

 
 
 
4,425

 
Earnings before income taxes
 
898

 
 
 
1,045

 
 
 
1,075

 
 
 
999

 
Total income tax
 
306

 
 
 
332

 
 
 
359

 
 
 
(1,585
)
 
Net earnings
 
$
592

 
 
 
$
713

 
 
 
$
716

 
 
 
$
2,584

 
Net earnings per basic share
 
$
.74

 
 
 
$
.90

 
 
 
$
.91

 
 
 
$
3.29

 
Net earnings per diluted share
 
.73

 
 
 
.89

 
 
 
.90

 
 
 
3.27

 

Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.
v3.10.0.1
SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT
 12 Months Ended
Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]  
SCHEDULE II CONDENSED FINANCIAL INFORMATION OF REGISTRANT SCHEDULE II
CONDENSED FINANCIAL INFORMATION OF REGISTRANT

Aflac Incorporated (Parent Only)
Condensed Statements of Earnings
 
Years ended December 31,
(In millions)
2018
    
2017
    
2016
Revenues:
 
 
 
    
 
 
 
    
 
 
 
   Management and service fees from subsidiaries(1)
 
$
190

 
    
 
$
297

 
    
 
$
265

 
   Net investment income
 
69

 
    
 
30

 
    
 
18

 
   Interest from subsidiaries(1)
 
4

 
    
 
5

 
    
 
5

 
   Realized investment gains (losses)
 
90

 
    
 
67

 
    
 
84

 
   Change in fair value of the cross-currency interest rate swaps
 
(106
)
 
    
 
(68
)
 
    
 
(159
)
 
     Total revenues
 
247

 
    
 
331

 
    
 
213

 
Operating expenses:
 
 
 
    
 
 
 
    
 
 
 
   Interest expense
 
188

 
    
 
197

 
    
 
213

 
   Other operating expenses(2)
 
225

 
    
 
180

 
    
 
277

 
     Total operating expenses
 
413

 
    
 
377

 
    
 
490

 
   Earnings before income taxes and equity in earnings of
subsidiaries
 
(166
)
 
    
 
(46
)
 
    
 
(277
)
 
Income tax expense (benefit)
 
(12
)
 
    
 
(23
)
 
    
 
(102
)
 
   Earnings before equity in earnings of subsidiaries
 
(154
)
 
    
 
(23
)
 
    
 
(175
)
 
Equity in earnings of subsidiaries(1)
 
3,074

 
    
 
4,627

 
    
 
2,834

 
     Net earnings
 
$
2,920

 
    
 
$
4,604

 
    
 
$
2,659

 
(1)Eliminated in consolidation
(2)Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt
See the accompanying Notes to Condensed Financial Statements.
See the accompanying Report of Independent Registered Public Accounting Firm.SCHEDULE II
CONDENSED FINANCIAL INFORMATION OF REGISTRANT
Aflac Incorporated (Parent Only)
Condensed Statements of Comprehensive Income (Loss)
  
Years ended December 31,
(In millions)
2018
 
2017
 
2016
Net earnings
 
$
2,920

 
 
 
$
4,604

 
 
 
$
2,659

 
Other comprehensive income (loss) before income taxes:
 
 
 
 
 
 
 
 
 
 
 
Unrealized foreign currency translation gains (losses) during period
 
232

 
 
 
286

 
 
 
283

 
Unrealized gains (losses) on fixed maturity securities during period (1)
 
(3,109
)
 
 
 
1,733

 
 
 
2,799

 
Unrealized gains (losses) on derivatives during period
 
2

 
 
 
1

 
 
 
3

 
Pension liability adjustment during period
 
(25
)
 
 
 
9

 
 
 
(45
)
 
Total other comprehensive income (loss) before
income taxes
 
(2,900
)
 
 
 
2,029

 
 
 
3,040

 
Income tax expense (benefit) related to items of other comprehensive
income (loss)
 
(797
)
 
 
 
631

 
 
 
1,035

 
Other comprehensive income (loss), net of income taxes
 
(2,103
)
 
 
 
1,398

 
 
 
2,005

 
Total comprehensive income (loss)
 
$
817

 
 
 
$
6,002

 
 
 
$
4,664

 

(1) See Note 1 of Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
See the accompanying Notes to Condensed Financial Statements.
See the accompanying Report of Independent Registered Public Accounting Firm.SCHEDULE II
CONDENSED FINANCIAL INFORMATION OF REGISTRANT
Aflac Incorporated (Parent Only)
Condensed Balance Sheets
  
December 31,
(In millions, except for share and per-share amounts)
2018
 
2017
Assets:
 
 
 
 
 
 
 
Investments and cash:
 
 
 
 
 
 
 
Fixed maturity securities available for sale, at fair value
(amortized cost $1,209 in 2018 and $1,163 in 2017)
 
$
1,222

 
 
 
$
1,213

 
Investments in subsidiaries(1)
 
26,230

 
 
 
26,869

 
Other investments
 
21

 
 
 
51

 
Cash and cash equivalents
 
1,767

 
 
 
1,725

 
Total investments and cash
 
29,240

 
 
 
29,858

 
Due from subsidiaries(1)
 
98

 
 
 
90

 
Income taxes receivable
 
176

 
 
 
121

 
Other assets
 
390

 
 
 
366

 
Total assets
 
$
29,904

 
 
 
$
30,435

 
 
 
 
 
 
 
 
 
Liabilities and shareholders' equity:
 
 
 
 
 
 
 
Liabilities:
 
 
 
 
 
 
 
Employee benefit plans
 
$
310

 
 
 
$
341

 
Notes payable
 
5,765

 
 
 
5,267

 
Other liabilities
 
367

 
 
 
229

 
Total liabilities
 
6,442

 
 
 
5,837

 
Shareholders' equity:
 
 
 
 
 
 
 
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2018 and 2017; issued 1,347,540 shares in 2018 and 1,345,762 shares in 2017
 
135

 
 
 
135

 
Additional paid-in capital
 
2,177

 
 
 
2,052

 
Retained earnings
 
31,788

 
 
 
29,895

 
Accumulated other comprehensive income (loss):
 
 
 
 
 
 
 
Unrealized foreign currency translation gains (losses)
 
(1,847
)
 
 
 
(1,750
)
 
Unrealized gains (losses) on fixed maturity securities (2)
 
4,234

 
 
 
5,964

 
Unrealized gains (losses) on derivatives
 
(24
)
 
 
 
(23
)
 
Pension liability adjustment
 
(212
)
 
 
 
(163
)
 
Treasury stock, at average cost
 
(12,789
)
 
 
 
(11,512
)
 
Total shareholders' equity
 
23,462

 
 
 
24,598

 
Total liabilities and shareholders' equity
 
$
29,904

 
 
 
$
30,435

 

(1)Eliminated in consolidation
(2) See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
See the accompanying Notes to Condensed Financial Statements.
See the accompanying Report of Independent Registered Public Accounting Firm.SCHEDULE II
CONDENSED FINANCIAL INFORMATION OF REGISTRANT
Aflac Incorporated (Parent Only)
Condensed Statements of Cash Flows
  
Years ended December 31,
(In millions)
2018
 
2017
 
2016
Cash flows from operating activities:
 
 
 
 
 
 
 
 
 
 
 
Net earnings
 
$
2,920

 
 
 
$
4,604

 
 
 
$
2,659

 
Adjustments to reconcile net earnings to net cash provided from
operating activities:
 
 
 
 
 
 
 
 
 
 
 
              Equity in earnings of subsidiaries(1)
 
(3,074
)
 
 
 
(4,627
)
 
 
 
(2,834
)
 
 Cash dividends received from subsidiaries
 
1,820

 
 
 
2,001

 
 
 
2,020

 
 Other, net
 
99

 
 
 
(46
)
 
 
 
294

(2) 
Net cash provided (used) by operating activities
 
1,765

 
 
 
1,932

 
 
 
2,139

 
Cash flows from investing activities:
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities sold
 
207

 
 
 
263

 
 
 
225

 
Fixed maturity securities purchased
 
(254
)
 
 
 
(329
)
 
 
 
(229
)
 
Other investments sold (purchased)
 
31

 
 
 
(47
)
 
 
 
6

 
Settlement of derivatives
 
(2
)
 
 
 
223

 
 
 
0

 
Additional capitalization of subsidiaries(1)
 
(62
)
 
 
 
(69
)
 
 
 
(36
)
 
Other, net
 
(107
)
 
 
 
(218
)
 
 
 
(25
)
 
Net cash provided (used) by investing activities
 
(187
)
 
 
 
(177
)
 
 
 
(59
)
 
Cash flows from financing activities:
 
 
 
 
 
 
 
 
 
 
 
Purchases of treasury stock
 
(1,301
)
 
 
 
(1,351
)
 
 
 
(1,422
)
 
Proceeds from borrowings
 
1,020

 
 
 
1,040

 
 
 
986

 
Principal payments under debt obligations
 
(550
)
 
 
 
(1,161
)
 
 
 
(621
)
 
Dividends paid to shareholders
 
(793
)
 
 
 
(661
)
 
 
 
(658
)
 
Treasury stock reissued
 
58

 
 
 
33

 
 
 
46

 
Proceeds from exercise of stock options
 
34

 
 
 
38

 
 
 
36

 
       Net change in amount due to/from subsidiaries(1)
 
(4
)
 
 
 
(5
)
 
 
 
(6
)
 
Other, net
 
0

 
 
 
0

 
 
 
(125
)
(2) 
Net cash provided (used) by financing activities
 
(1,536
)
 
 
 
(2,067
)
 
 
 
(1,764
)
 
Net change in cash and cash equivalents
 
42

 
 
 
(312
)
 
 
 
316

 
Cash and cash equivalents, beginning of period
 
1,725

 
 
 
2,037

 
 
 
1,721

 
Cash and cash equivalents, end of period
 
$
1,767

 
 
 
$
1,725

 
 
 
$
2,037

 

(1)Eliminated in consolidation
(2)Operating activities excludes and financing activities includes a cash outflow of $137 in 2016 for the payment associated with the early extinguishment of debt
See the accompanying Notes to Condensed Financial Statements.
See the accompanying Report of Independent Registered Public Accounting Firm.(A) Notes Payable
A summary of notes payable as of December 31 follows:
(In millions)
2018
 
2017
2.40% senior notes paid November 2018
 
$
0

 
 
 
$
548

 
4.00% senior notes due February 2022
 
348

 
 
 
348

 
3.625% senior notes due June 2023
 
698

 
 
 
697

 
3.625% senior notes due November 2024
 
746

 
 
 
745

 
3.25% senior notes due March 2025
 
447

 
 
 
446

 
2.875% senior notes due October 2026
 
297

 
 
 
297

 
6.90% senior notes due December 2039
 
220

 
 
 
220

 
6.45% senior notes due August 2040
 
254

 
 
 
254

 
4.00% senior notes due October 2046
 
394

 
 
 
394

 
4.750% senior notes due January 2049
 
540

 
 
 
0

 
Yen-denominated senior notes and subordinated debentures:
 
 
 
 
 
 
 
.932% senior notes due January 2027 (principal amount 60.0 billion yen)
 
538

  
  
 
528

  
1.159% senior notes due October 2030 (principal amount 29.3 billion yen)
 
262

 
 
 
0

 
1.488% senior notes due October 2033 (principal amount 15.2 billion yen)
 
136

 
 
 
0

 
1.750% senior notes due October 2038 (principal amount 8.9 billion yen)
 
79

 
 
 
0

 
2.108% subordinated debentures due October 2047 (principal amount 60.0 billion yen)
 
536

 
 
 
526

 
Yen-denominated loans:
 
 
 
 
 
 
 
Variable interest rate loan due September 2021 (.32% in 2018 and 2017, principal amount 5.0 billion yen)
 
45

 
 
 
44

 
Variable interest rate loan due September 2023 (.47% in 2018 and 2017, principal amount 25.0 billion yen)
 
225

 
 
 
220

 
Total notes payable
 
$
5,765

  
  
 
$
5,267

  

Amounts in the table above are reported net of debt issuance costs and issuance premiums or discounts, if applicable, that are being amortized over the life of the notes.

In October 2018, the Parent Company issued $550 million of senior notes through a U.S. public debt offering. The notes bear interest at a fixed rate of 4.750% per annum, payable semi-annually, and have a 30-year maturity. These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date. In November 2018, the Parent Company used the net proceeds from the October 2018 issuance of senior notes to redeem $550 million of the Parent Company's 2.40% senior notes due in 2020.

In October 2018, the Parent Company issued three series of senior notes totaling 53.4 billion yen through a public debt offering under its U.S. shelf registration statement. The first series, which totaled 29.3 billion yen, bears interest at a fixed rate of 1.159% per annum, payable semi-annually, and has a 12-year maturity. The second series, which totaled 15.2 billion yen, bears interest at a fixed rate of 1.488% per annum, payable semi-annually, and has a 15-year maturity.
The third series, which totaled 8.9 billion yen, bears interest at a fixed rate of 1.750% per annum, payable semi-annually, and has a 20-year maturity. These notes may only be redeemed before maturity, in whole but not in part, upon the occurrence of certain changes affecting U.S. taxation, as specified in the indenture governing the terms of the issuance.

The aggregate contractual maturities of notes payable during each of the years after December 31, 2018, are as follows:
(In millions)
 
 
2019
$
0

 
2020
0

 
2021
45

 
2022
350

 
2023
925

 
Thereafter
4,493

 
Total
$
5,813

 

For further information regarding notes payable, see Note 9 of the Notes to the Consolidated Financial Statements.(B) DerivativesAt December 31, 2018, the Parent Company's outstanding freestanding derivative contracts were swaps associated with its notes payable, consisting of cross-currency interest rate swaps, also referred to as foreign currency swaps, associated with the Parent Company's senior notes due in February 2022, June 2023, November 2024 and March 2025. The Parent Company does not use derivative financial instruments for trading purposes, nor does it engage in leveraged derivative transactions. For further information regarding these derivatives, see Notes 1, 4 and 9 of the Notes to the Consolidated Financial Statements.(C) Income TaxesThe Parent Company and its eligible U.S. subsidiaries file a consolidated U.S. federal income tax return. Income tax liabilities or benefits are recorded by each principal subsidiary based upon separate return calculations, and any difference between the consolidated provision and the aggregate amounts recorded by the subsidiaries is reflected in the Parent Company financial statements. For further information on income taxes, see Note 10 of the Notes to the Consolidated Financial Statements.(D) Dividend Restrictions

See Note 13 of the Notes to the Consolidated Financial Statements for information regarding dividend restrictions.(E) Supplemental Disclosures of Cash Flow Information
(In millions)
2018
 
2017
 
2016
Interest paid
 
$
179

 
 
 
$
195

 
 
 
$
209

 
Noncash financing activities:
 
 
 
 
 
 
 
 
 
 
 
Treasury stock issued for shareholder dividend reinvestment
 
8

 
 
 
29

 
 
 
26

 
v3.10.0.1
SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION
 12 Months Ended
Dec. 31, 2018
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]  
SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION SCHEDULE III
SUPPLEMENTARY INSURANCE INFORMATION
Aflac Incorporated and Subsidiaries
Years ended December 31,
(In millions)
Deferred Policy
Acquisition
Costs
 
Future Policy
Benefits & Unpaid
Policy Claims
 
Unearned
Premiums
 
Other
Policyholders'
Funds
2018:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
6,384

 
 
 
$
80,672

 
 
 
$
4,977

 
 
 
$
7,145

 
Aflac U.S.
 
3,491

 
 
 
10,864

 
 
 
117

 
 
 
0

 
All other
 
0

 
 
 
183

 
 
 
0

 
 
 
1

 
Intercompany eliminations
 
0

 
 
 
(767
)
 
 
 
(4
)
 
 
 
0

 
Total
 
$
9,875

 
 
 
$
90,952

 
 
 
$
5,090

 
 
 
$
7,146

 
2017:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
6,150

 
 
 
$
76,353

 
 
 
$
5,840

 
 
 
$
6,939

 
Aflac U.S.
 
3,355

 
 
 
10,506

 
 
 
119

 
 
 
0

 
All other
 
0

 
 
 
138

 
 
 
0

 
 
 
0

 
Intercompany eliminations
 
0

 
 
 
(748
)
 
 
 
0

 
 
 
0

 
Total
 
$
9,505

 
 
 
$
86,249

 
 
 
$
5,959

 
 
 
$
6,939

 
Segment amounts may not agree in total to the corresponding consolidated amounts due to rounding.
Years Ended December 31,
(In millions)
Net
Premium
Revenue
 
Net
Investment
Income
 
Benefits and
Claims, net
 
Amortization of
Deferred Policy
Acquisition Costs
 
Other
Operating
Expenses
 
Premiums
Written
2018:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
$
12,762

 
 
$
2,639

 
 
 
$
8,913

 
 
 
$
710

 
 
 
$
2,374

 
 
$
12,298

Aflac U.S.
5,708

 
 
727

 
 
 
2,887

 
 
 
534

 
 
 
1,736

 
 
5,707

All other
207

 
 
76

 
 
 
200

 
 
 
1

 
 
 
420

 
 
0

Total
$
18,677

 
 
$
3,442

 
 
 
$
12,000

 
 
 
$
1,245

 
 
 
$
4,530

 
 
$
18,005

2017:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
$
12,752

 
 
$
2,463

 
 
 
$
9,087

 
 
 
$
630

 
 
 
$
2,257

 
 
$
12,092

Aflac U.S.
5,563

 
 
721

 
 
 
2,885

 
 
 
502

 
 
 
1,658

 
 
5,565

All other
216

 
 
36

 
 
 
209

 
 
 
0

 
 
 
421

 
 
0

Total
$
18,531

 
 
$
3,220

 
 
 
$
12,181

 
 
 
$
1,132

 
 
 
$
4,336

 
 
$
17,657

2016:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
$
13,537

 
 
$
2,554

 
 
 
$
9,828

 
 
 
$
644

 
 
 
$
2,326

 
 
$
12,762

Aflac U.S.
5,454

 
 
703

 
 
 
2,869

 
 
 
497

 
 
 
1,593

 
 
5,452

All other
234

 
 
21

 
 
 
222

 
 
 
0

 
 
 
513

 
 
0

Total
$
19,225

 
 
$
3,278

 
 
 
$
12,919

 
 
 
$
1,141

 
 
 
$
4,432

 
 
$
18,214


Segment amounts may not agree in total to the corresponding consolidated amounts due to rounding.
See the accompanying Report of Independent Registered Public Accounting Firm.
v3.10.0.1
SCHEDULE IV REINSURANCE
 12 Months Ended
Dec. 31, 2018
Reinsurance Disclosures [Abstract]  
SCHEDULE IV REINSURANCE SCHEDULE IV
REINSURANCE
Aflac Incorporated and Subsidiaries
Years Ended December 31,
(In millions)
Gross
Amount
 
Ceded to
Other
Companies
 
Assumed
from Other
companies
 
Net
Amount
 
Percentage
of Amount
Assumed
to Net
2018:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Life insurance in force
$
151,457

 
 
$
4,702

 
 
 
$
0

 
 
$
146,755

 
 
0
%
 
Premiums:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Health insurance
$
15,330

 
 
$
541

 
 
 
$
214

 
 
$
15,003

 
 
1
%
 
Life insurance
3,688

 
 
14

 
 
 
0

 
 
3,674

 
 
0

 
Total earned premiums
$
19,018

 
 
$
555

 
 
 
$
214

 
 
$
18,677

 
 
1
%
 
2017:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Life insurance in force
$
152,502

 
 
$
4,121

 
 
 
$
0

 
 
$
148,381

 
 
0
%
 
Premiums:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Health insurance
$
14,829

 
 
$
554

 
 
 
$
222

 
 
$
14,497

 
 
1
%
 
Life insurance
4,046

 
 
12

 
 
 
0

 
 
4,034

 
 
0

 
Total earned premiums
$
18,875

 
 
$
566

 
 
 
$
222

 
 
$
18,531

 
 
1
%
 
2016:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Life insurance in force
$
151,093

 
 
$
3,741

 
 
 
$
0

 
 
$
147,352

 
 
0
%
 
Premiums:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Health insurance
$
14,839

 
 
$
595

 
 
 
$
241

 
 
$
14,485

 
 
1
%
 
Life insurance
4,753

 
 
13

 
 
 
0

 
 
4,740

 
 
0

 
Total earned premiums
$
19,592

 
 
$
608

 
 
 
$
241

 
 
$
19,225

 
 
1
%
 

Premiums by type may not agree in total to the corresponding consolidated amounts due to rounding.
See the accompanying Report of Independent Registered Public Accounting Firm.
v3.10.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)
 12 Months Ended
Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Description of Business and Basis of Presentation Description of Business 
Aflac Incorporated (the Parent Company) and its subsidiaries (collectively, the Company) primarily sell supplemental health and life insurance in the United States and Japan. The Company's insurance business is marketed and administered through American Family Life Assurance Company of Columbus (Aflac) in the United States (Aflac U.S.) and, effective April 1, 2018, through Aflac Life Insurance Japan Ltd. in Japan (Aflac Japan). Prior to April 1, 2018, the Company's insurance business was marketed in Japan as a branch of Aflac. American Family Life Assurance Company of New York (Aflac New York) is a wholly owned subsidiary of Aflac. Most of Aflac's policies are individually underwritten and marketed through independent agents. Additionally, Aflac U.S. markets and administers group products through Continental American Insurance Company (CAIC), branded as Aflac Group Insurance. The Company's insurance operations in the United States and Japan service the two markets for the Company's insurance business. Aflac Japan's revenues, including realized gains and losses on its investment portfolio, accounted for 70% of the Company's total revenues in 2018, compared with 70% in 2017 and 71% in 2016. The percentage of the Company's total assets attributable to Aflac Japan was 84% at December 31, 2018, compared with 83% at December 31, 2017.

Basis of Presentation
The Company prepares its financial statements in accordance with U.S. generally accepted accounting principles (U.S. GAAP). These principles are established primarily by the Financial Accounting Standards Board (FASB). In these Notes to the Consolidated Financial Statements, references to U.S. GAAP issued by the FASB are derived from the FASB Accounting Standards CodificationTM (ASC). The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates based on currently available information when recording transactions resulting from business operations. The most significant items on the Company's balance sheet that involve a greater degree of accounting estimates and actuarial determinations subject to changes in the future are the valuation of investments and derivatives, deferred policy acquisition costs (DAC), liabilities for future policy benefits and unpaid policy claims, and income taxes. These accounting estimates and actuarial determinations are sensitive to market conditions, investment yields, mortality, morbidity, commission and other acquisition expenses, and terminations by policyholders. As additional information becomes available, or actual amounts are determinable, the recorded estimates will be revised and reflected in operating results. Although some variability is inherent in these estimates, the Company believes the amounts provided are adequate.

The consolidated financial statements include the accounts of the Parent Company, its subsidiaries, and those entities required to be consolidated under applicable accounting standards. All material intercompany accounts and transactions have been eliminated.
Translation of Foreign Currencies Foreign Currency Translation: The functional currency of Aflac Japan is the Japanese yen. The Company translates its yen-denominated financial statement accounts into U.S. dollars as follows. Assets and liabilities are translated at end-of-period exchange rates. Realized gains and losses on security transactions are translated at the exchange rate on the trade date of each transaction. Other revenues, expenses, and cash flows are translated using average exchange rates for the period. The resulting currency translation adjustments are reported in accumulated other comprehensive income. The Company includes in earnings the realized currency exchange gains and losses resulting from foreign currency transactions.

The Parent Company has designated a majority of its yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedges and from time-to-time may designate certain foreign currency forwards and options as derivative hedges of the foreign currency exposure of the Company's net investment in Aflac Japan. Outstanding principal and related accrued interest on these Parent Company liabilities and the fair value of these derivatives are translated into U.S. dollars at end-of-period exchange rates. Currency translation adjustments and changes in the fair value of these derivatives are recorded as unrealized foreign currency translation gains (losses) in other comprehensive income and are included in accumulated other comprehensive income.
Insurance Revenue and Expense Recognition Insurance Revenue and Expense Recognition: Substantially all of the supplemental health and life insurance policies the Company issues are classified as long-duration contracts. The contract provisions generally cannot be
changed or canceled during the contract period; however, the Company may adjust premiums for supplemental health policies issued in the United States within prescribed guidelines and with the approval of state insurance regulatory authorities.

Insurance premiums for most of the Company's health and life policies, including cancer, accident, hospital, critical illness, dental, vision, term life, whole life, long-term care and disability, are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. When revenues are reported, the related amounts of benefits and expenses are charged against such revenues, so that profits are recognized in proportion to premium revenues during the period the policies are expected to remain in force. This association is accomplished by means of annual additions to the liability for future policy benefits and the deferral and subsequent amortization of policy acquisition costs.

Premiums from the Company's products with limited-pay features, including term life, whole life, WAYS, and child endowment, are collected over a significantly shorter period than the period over which benefits are provided. Premiums for these products are recognized as revenue over the premium-paying periods of the contracts when due from policyholders. Any gross premium in excess of the net premium is deferred and recorded in earnings, such that profits are recognized in a constant relationship with insurance in force. Benefits are recorded as an expense when they are incurred. A liability for future policy benefits is recorded when premiums are recognized using the net premium method.

At the policyholder's option, customers can also pay discounted advanced premiums for certain of the Company's products. Advanced premiums are deferred and recognized when due from policyholders over the regularly scheduled premium payment period.

The calculation of DAC and the liability for future policy benefits requires the use of estimates based on sound actuarial valuation techniques. For new policy issues, the Company reviews its actuarial assumptions and deferrable acquisition costs each year and revises them when necessary to more closely reflect recent experience and studies of actual acquisition costs. For policies in force, the Company evaluates DAC by major product groupings to determine that they are recoverable from future revenues, and any amounts determined not to be recoverable are charged against net earnings. The Company has not had any material charges to earnings for DAC that was determined not to be recoverable in any of the years presented in this Form 10-K.
Advertising Cost, Policy, Expensed Advertising Cost Advertising expense is reported as incurred in insurance expenses in the consolidated statements of earnings.
Cash and Cash Equivalents Cash and Cash Equivalents: Cash and cash equivalents include cash on hand, money market instruments, and other debt instruments with a maturity of 90 days or less when purchased.
Investments Investments: The Company's debt securities consist of fixed maturity securities, which are classified as either held to maturity or available for sale. Securities classified as held to maturity are securities that the Company has the ability and intent to hold to maturity or redemption and are carried at amortized cost. All other fixed maturity debt securities are classified as available for sale and are carried at fair value. If the fair value is higher than the amortized cost for debt securities, the excess is an unrealized gain, and if lower than cost, the difference is an unrealized loss. The net unrealized gains and losses on securities available for sale, less related deferred income taxes, are recorded through other comprehensive income and included in accumulated other comprehensive income.

Amortized cost of debt securities is based on the Company's purchase price adjusted for accrual of discount, or amortization of premium, and recognition of impairment charges, if any. The amortized cost of debt securities the Company purchases at a discount or premium will equal the face or par value at maturity or the call date, if applicable. Interest is reported as income when earned and is adjusted for amortization of any premium or discount.

The Company has investments in equity securities which are carried at fair value. Effective January 1, 2018 upon the adoption of new accounting guidance, changes in fair value of equity securities are recorded in earnings as a component of realized investment gains and losses. Prior to January 1, 2018, equity securities were carried at fair value with unrealized gains and losses, less related deferred income taxes, recorded in other comprehensive income and included in accumulated other comprehensive income.

The Company has investments in variable interest entities (VIEs). Criteria for evaluating VIEs for consolidation focuses on identifying which enterprise has the power to direct the activities of a variable interest entity that most significantly impact the entity's economic performance and (1) the obligation to absorb losses of the entity or (2) the right to receive benefits from the entity. The Company is the primary beneficiary of certain VIEs, and therefore consolidates these entities in its financial statements. While the consolidated VIEs generally operate within a defined set of contractual
terms, there are certain powers that are retained by the Company that are considered significant in the conclusion that the Company is the primary beneficiary. These powers vary by structure but generally include the initial selection of the underlying collateral; the ability to obtain the underlying collateral in the event of default; and, the ability to appoint or dismiss key parties in the structure. In particular, the Company's powers surrounding the underlying collateral were considered to be the most significant powers because those most significantly impact the economics of the VIE. The Company has no obligation to provide any continuing financial support to any of the entities in which it is the primary beneficiary. The Company's maximum loss is limited to its original investment. Neither the Company nor any of its creditors have the ability to obtain the underlying collateral, nor does the Company have control over the instruments held in the VIEs, unless there is an event of default. For those entities where the Company is the primary beneficiary, the consolidated entity's assets are segregated on the balance sheet by the caption "consolidated variable interest entities," and consist of fixed maturity securities, equity securities, loan receivables, limited partnerships and derivative instruments.

For the mortgage- and asset-backed securities held in the Company's fixed maturity portfolio, the Company recognizes income using a constant effective yield, which is based on anticipated prepayments and the estimated economic life of the securities. When estimates of prepayments change, the effective yield is recalculated to reflect actual payments to date and anticipated future payments. The net investment in mortgage- and asset-backed securities is adjusted to the amount that would have existed had the new effective yield been applied at the time of acquisition. This adjustment is reflected in net investment income.

The Company uses the specific identification method to determine the gain or loss from securities transactions and report the realized gain or loss in the consolidated statements of earnings. Securities transactions are accounted for based on values as of the trade date of the transaction.

An investment in a fixed maturity security is impaired if the fair value falls below amortized cost. The Company regularly reviews its fixed maturity security investments portfolio for declines in fair value. The Company's fixed maturity security investments are evaluated for other-than-temporary impairment using its debt impairment model. The Company's debt impairment model focuses on the ultimate collection of the cash flows from its investments and whether the Company has the intent to sell or if it is more likely than not the Company would be required to sell the security prior to recovery of its amortized cost. The determination of the amount of impairments under this model is based upon the Company's periodic evaluation and assessment of known and inherent risks associated with the respective securities. Such evaluations and assessments are revised as conditions change and new information becomes available.
When determining the Company's intention to sell a security prior to recovery of its fair value to amortized cost, the Company evaluates facts and circumstances such as, but not limited to, future cash flow needs, decisions to reposition its security portfolio, and risk profile of individual investment holdings. The Company performs ongoing analyses of its liquidity needs, which includes cash flow testing of its policy liabilities, debt maturities, projected dividend payments, and other cash flow and liquidity needs.

The determination of whether an impairment in value of the Company's fixed maturity securities is other than temporary is based largely on the Company's evaluation of the issuer's creditworthiness. The Company must apply considerable judgment in determining the likelihood of its fixed maturity securities recovering in value. Factors that may influence this include the overall level of interest rates, credit spreads, the credit quality of the underlying issuer, and other factors. This process requires consideration of risks which can be controlled to a certain extent, such as credit risk, and risks which cannot be controlled, such as interest rate risk and foreign currency risk.

If, after monitoring and analyses, management believes that fair value will not recover to amortized cost, the Company recognizes an other-than-temporary impairment of the security. Once a security is considered to be other-than-temporarily impaired, the impairment loss is separated into two components: the portion of the impairment related to credit and the portion of the impairment related to factors other than credit. The Company recognizes a charge to earnings for the credit-related portion of other-than-temporary impairments. Impairments related to factors other than credit are charged to earnings in the event the Company intends to sell the security prior to the recovery of its amortized cost or if it is more likely than not that the Company would be required to dispose of the security prior to recovery of its amortized cost; otherwise, non-credit-related other-than-temporary impairments are charged to other comprehensive income.

The Company lends fixed maturity and public equity securities to financial institutions in short-term security-lending transactions. These securities continue to be carried as investment assets on the Company's balance sheet during the terms of the loans and are not reported as sales. The Company receives cash or other securities as collateral for such loans. For loans involving unrestricted cash or securities as collateral, the collateral is reported as an asset with a corresponding liability for the return of the collateral. For loans where the Company receives as collateral securities that the Company is not permitted to sell or repledge, the collateral is not reported as an asset.

Other investments include transitional real estate loans (TREs), commercial mortgage loans (CMLs), middle market loans (MMLs), policy loans, limited partnerships, and short-term investments with maturities at the time of purchase of one year or less, but greater than 90 days. The Company's investments in TREs, CMLs, and MMLs are accounted for as loan receivables and are recorded at amortized cost on the acquisition date. The Company has the intent and ability to hold these loan receivables for the foreseeable future or until they mature and therefore, they are considered held for investment and are carried at amortized cost in the other investments line in its consolidated balance sheets. The amortized cost of the loan receivables reflects allowances for expected incurred losses estimated based on past events and current economic conditions as of each reporting date. Limited partnership investments are accounted for using the equity method of accounting. Under the equity method of accounting, the Company reports its portion of partnership earnings as a component of net investment income in its consolidated statements of earnings. The underlying investments held by the Company’s limited partnerships primarily consist of private equity and real estate. Short-term investments are stated at amortized cost, which approximates fair value.
Derivatives and Hedging Derivatives and Hedging: Freestanding derivative instruments are reported in the consolidated balance sheet at fair value and are reported in other assets and other liabilities, with changes in value reported in earnings and/or other comprehensive income. These freestanding derivatives are foreign currency forwards, foreign currency options, foreign currency swaps, interest rate swaps, interest rate swaptions, and, in prior year periods, credit default swaps (CDSs). Foreign currency forwards and options are used in hedging foreign exchange risk on U.S. dollar-denominated investments in Aflac Japan's portfolio. Foreign currency forwards and options are also used to economically hedge certain portions of forecasted cash flows denominated in yen and hedge the Company's long term exposure to a weakening yen. Cross-currency interest rate swaps, also referred to as foreign currency swaps, are used to economically convert certain U.S. dollar-denominated note obligations into yen-denominated principal and interest obligations. Foreign currency swaps are used within special-purpose entities, including VIEs where the Company is the primary beneficiary, to hedge the risk arising from interest rate and currency exchange risk. Interest rate swaps are used to economically hedge interest rate fluctuations in certain variable-rate investments. Interest rate swaptions, which are options to enter into interest rate swaps, are used to hedge interest rate fluctuations on certain U.S. dollar-denominated available-for-sale securities in Aflac Japan's portfolio. The Company does not use derivatives for trading purposes, nor does the Company engage in leveraged derivative transactions.

From time to time, the Company purchases certain investments that contain an embedded derivative. The Company assesses whether this embedded derivative is clearly and closely related to the asset that serves as its host contract. If the Company deems that the embedded derivative's terms are not clearly and closely related to the host contract, and a separate instrument with the same terms would qualify as a derivative instrument, the derivative is separated from that contract, held at fair value, and reported with the host instrument in the consolidated balance sheet, with changes in fair value reported in earnings. If the Company has elected the fair value option, the embedded derivative is not bifurcated, and the entire investment is held at fair value with changes in fair value reported in earnings.
See Note 5 for a discussion on how the Company determines the fair value of its derivatives. Accruals on derivatives are typically recorded in accrued investment income or within other liabilities in the consolidated balance sheets.

To qualify for hedge accounting treatment, a derivative must be highly effective in mitigating the designated risk attributable to the hedged item. At the inception of hedging relationships the Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objectives and strategies for undertaking the respective hedging relationship, and the methodology that will be used to assess the effectiveness of the hedge relationship at and subsequent to hedge inception. The Company documents the designation of each hedge as either (i) a hedge of the variability of cash flows to be received or paid related to a recognized asset or liability or the hedge of a forecasted transaction ("cash flow hedge"); (ii) a hedge of the estimated fair value of a recognized asset or liability ("fair value hedge"); or (iii) a hedge of a net investment in a foreign operation. The documentation process includes linking derivatives and non-derivative financial instruments that are designated as hedges to specific assets or groups of assets or liabilities in the statement of financial position or to specific forecasted transactions and defining the effectiveness testing methods to be used. At the hedge inception and on an ongoing quarterly basis, the Company also formally assesses whether the derivatives and non-derivative financial instruments used in hedging activities have been, and are expected to continue to be, highly effective in offsetting their designated risk. Hedge effectiveness is assessed using qualitative and quantitative methods. The assessment of hedge effectiveness determines the accounting treatment of changes in fair value.
For assessing hedge effectiveness, qualitative methods may include the comparison of critical terms of the derivative to the hedged item, and quantitative methods may include regression, dollar offset, or other statistical analysis of changes in fair value or cash flows associated with the hedge relationship. For derivative instruments that are designated and
qualify as cash flow hedges, the gain or loss on the derivative is reported as a component of other comprehensive income (loss) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. In cash flow hedges, all components of each derivative's gain or loss are included in the assessment of hedge effectiveness and are recorded in the line item of the consolidated statements of earnings in which the cash flows of the hedged item are recorded.
For derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the hedged item and the portion of the hedging instrument included in the assessment of effectiveness are recorded in the line item of the consolidated statements of earnings in which gain or loss on the hedged item is recorded. When assessing the effectiveness of the Company's fair value hedges, the Company excludes the changes in fair value related to the difference between the spot and the forward rate on its foreign currency forwards and the time value of foreign exchange options and interest rate swaptions.
For hedges of the Company's net investment in Aflac Japan, the Company has designated the majority of the Parent Company's yen-denominated liabilities (notes payable and yen-denominated loans) as non-derivative hedging instruments and from time to time may designate certain foreign currency forwards and options as derivative hedging instruments. The Company makes its net investment hedge designation at the beginning of each quarter. For assessing hedge effectiveness of net investment hedges, if the total of the designated Parent Company non-derivative and derivatives notional is equal to or less than its net investment in Aflac Japan, the hedge is deemed to be effective. If the hedge is effective, the related exchange effect on the yen-denominated liabilities is reported in the unrealized foreign currency component of other comprehensive income. For derivative hedging instruments designated as net investment hedges, Aflac follows the forward-rate method. According to that method, all changes in fair value, including changes related to the forward-rate component of foreign currency forward contracts and the time value of foreign currency options, are reported in the unrealized foreign currency component of other comprehensive income. Should these designated net investment hedge positions exceed the Company's net investment in Aflac Japan, the foreign exchange effect on the portion that exceeds its investment in Aflac Japan would be recognized in current earnings within derivative and other gains (losses).
The Company discontinues hedge accounting prospectively when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the estimated cash flows or fair value of a hedged item; (2) the derivative is de-designated as a hedging instrument; or (3) the derivative expires or is sold, terminated or exercised.
When hedge accounting is discontinued on a cash flow hedge or fair value hedge, the derivative is carried in the consolidated balance sheets at its estimated fair value, with changes in estimated fair value recognized in current period earnings. For discontinued cash flow hedges, including those where the derivative is sold, terminated or exercised, amounts previously deferred in other comprehensive income (loss) are reclassified into earnings when earnings are impacted by the cash flow of the hedged item.
If a derivative is not designated as an accounting hedge or its use in managing risk does not qualify for hedge accounting, changes in the estimated fair value of the derivative are generally reported within derivative and other gains (losses), which is a component of realized investment gains (losses). The fluctuations in estimated fair value of derivatives that have not been designated for hedge accounting can result in volatility in net earnings.

The Company receives and pledges cash or other securities as collateral on open derivative positions. Cash received as collateral is reported as an asset with a corresponding liability for the return of the collateral. Cash pledged as collateral is recorded as a reduction to cash, and a corresponding receivable is recognized for the return of the cash collateral. The Company generally can repledge or resell collateral obtained from counterparties, although the Company does not typically exercise such rights. Securities received as collateral are not recognized unless the Company was to exercise its right to sell that collateral or exercise remedies on that collateral upon a counterparty default. Securities that the Company has pledged as collateral continue to be carried as investment assets on its balance sheet.

Deferred Policy Acquisition Costs Deferred Policy Acquisition Costs: Certain direct and incremental costs of acquiring new business are deferred and amortized with interest over the premium payment periods in proportion to the ratio of annual premium income to total anticipated premium income. Anticipated premium income is estimated by using the same mortality, persistency and interest assumptions used in computing liabilities for future policy benefits. In this manner, the related acquisition expenses are matched with revenues. Deferred costs include the excess of current-year commissions over ultimate renewal-year commissions and certain incremental direct policy issue, underwriting and sales expenses. All of these incremental costs are directly related to successful policy acquisition.

For some products, policyholders can elect to modify product benefits, features, rights or coverages by exchanging a contract for a new contract or by amendment, endorsement, or rider to a contract, or by the election of a feature or coverage within a contract. These transactions are known as internal replacements. The Company performs a two-stage analysis of the internal replacements to determine if the modification is substantive to the base policy. The stages of evaluation are as follows: 1) determine if the modification is integrated with the base policy, and 2) if it is integrated, determine if the resulting contract is substantially changed.
For internal replacement transactions where the resulting contract is substantially unchanged, the policy is accounted for as a continuation of the replaced contract. Unamortized deferred acquisition costs from the original policy continue to be amortized over the expected life of the new policy, and the costs of replacing the policy are accounted for as policy maintenance costs and expensed as incurred. Examples include conversions of same age bands, certain family coverage changes, pricing era changes (decrease), and ordinary life becomes reduced paid-up and certain reinstatements.
An internal replacement transaction that results in a policy that is substantially changed is accounted for as an extinguishment of the original policy and the issuance of a new policy. Unamortized deferred acquisition costs on the original policy are immediately expensed, and the costs of acquiring the new policy are capitalized and amortized in accordance with the Company's accounting policies for deferred acquisition costs. Further, the policy reserves are evaluated based on the new policy features, and any change (up or down) necessary is recognized at the date of contract change/modification. Examples include conversions to higher age bands, certain family coverage changes, pricing era changes (increase), lapse & re-issue, certain reinstatements and certain other contract conversions.
Riders can be considered internal replacements that are either integrated or non-integrated resulting in either substantially changed or substantially unchanged treatment. Riders are evaluated based on the specific facts and circumstances of the rider and are considered an expansion of the existing benefits with additional premium required. Non-integrated riders to existing contracts do not change the Company's profit expectations for the related products and are treated as a new policy establishment for incremental coverage.
The Company measures the recoverability of DAC and the adequacy of its policy reserves annually by performing gross premium valuations on its business. (See the following discussion for further information regarding policy reserves.)
Policy Liabilities - Future Policy Benefits Policy Liabilities: Future policy benefits represent claims that are expected to occur in the future and are computed following a net level premium method using estimated future investment yields, persistency and recognized morbidity and mortality tables modified to reflect the Company's experience, including a provision for adverse deviation. These assumptions are generally established and considered locked at policy inception. These assumptions may only be unlocked in certain circumstances based on the results of periodic DAC recoverability and premium deficiency testing.
Policy Liabilities - Unpaid Policy Claims Unpaid policy claims are estimates computed on an undiscounted basis using statistical analyses of historical claims experience adjusted for current trends and changed conditions. The ultimate liability may vary significantly from such estimates. The Company regularly adjusts these estimates as new claims experience emerges and reflects the changes in operating results in the year such adjustments are made.
Other Policy Liabilities Other policy liabilities consist primarily of discounted advance premiums on deposit from policyholders in conjunction with their purchase of certain Aflac Japan limited-pay insurance products. These advanced premiums are deferred upon collection and recognized as premium revenue over the contractual premium payment period.
Internal Replacements of Insurance Contracts For internal replacements that are determined to not be substantially unchanged, policy liabilities related to the original policy that was replaced are immediately released, and policy liabilities are established for the new insurance contract; however, for internal replacements that are considered substantially unchanged, no changes to the reserves are recognized.
Reinsurance Accounting Policy Reinsurance: The Company enters into reinsurance agreements with other companies in the normal course of business. For each reinsurance agreement, the Company determines if the agreement provides indemnification against loss or liability relating to insurance risk in accordance with applicable accounting standards. Reinsurance premiums and benefits paid or provided are accounted for on bases consistent with those used in accounting for the original policies issued and the terms of the reinsurance contracts. Premiums, benefits and DAC are reported net of insurance ceded.
Income Taxes Income Taxes: Income tax provisions are generally based on pretax earnings reported for financial statement purposes, which differ from those amounts used in preparing the Company's income tax returns. Deferred income taxes are recognized for temporary differences between the financial reporting basis and income tax basis of assets and liabilities, based on enacted tax laws and statutory tax rates applicable to the periods in which the Company expects the temporary differences to reverse. The Company records deferred tax assets for tax positions taken based on its assessment of whether the tax position is more likely than not to be sustained upon examination by taxing authorities. A valuation allowance is established for deferred tax assets when it is more likely than not that an amount will not be realized.
Policyholder Protection Corporation and State Guaranty Association Assessments Policyholder Protection Corporation and State Guaranty Association Assessments: In Japan, the government has required the insurance industry to contribute to a policyholder protection corporation. The Company recognizes a charge for its estimated share of the industry's obligation once it is determinable. The Company reviews the estimated liability for policyholder protection corporation contributions on an annual basis and reports any adjustments in Aflac Japan's expenses.

In the United States, each state has a guaranty association that supports insolvent insurers operating in those states. See Note 15 of the Notes to the Consolidated Financial Statements for further discussion of the guaranty fund assessments charged to the Company.
Treasury Stock Treasury Stock: Treasury stock is reflected as a reduction of shareholders' equity at cost. The Company uses the weighted-average purchase cost to determine the cost of treasury stock that is reissued. The Company includes any gains and losses in additional paid-in capital when treasury stock is reissued.
Share-Based Compensation Share-Based Compensation: The Company measures compensation cost related to its share-based payment transactions at fair value on the grant date, and the Company recognizes those costs in the financial statements over the vesting period during which the employee provides service in exchange for the award. The Company has formalized its entity-wide accounting policy election to estimate the number of awards that are expected to vest and the corresponding forfeitures.
Earnings Per Share Earnings Per Share: The Company computes basic earnings per share (EPS) by dividing net earnings by the weighted-average number of unrestricted shares outstanding for the period. Diluted EPS is computed by dividing net earnings by the weighted-average number of shares outstanding for the period plus the shares representing the dilutive effect of share-based awards.
Reclassifications Stock Split: On February 13, 2018, the Board of Directors of the Parent Company declared a two-for-one stock split of the Company’s common stock in the form of a 100% stock dividend payable on March 16, 2018 to shareholders of record at the close of business on March 2, 2018. The stock split was payable in the form of one additional common stock share for every share of common stock held. All equity and share-based data, including the number of shares outstanding and per share amounts, have been adjusted to reflect the stock split for all periods presented in this Annual Report on Form 10-K.

Reclassifications: Certain reclassifications have been made to prior-year amounts to conform to current-year reporting classifications. These reclassifications had no impact on net earnings or total shareholders' equity.

Perpetual securities have been reclassified in prior periods from a separate line item to fixed maturity securities to conform to current period reporting classifications. This reclassification had no impact on net earnings or total shareholder’s equity.
Recently Adopted Accounting Pronouncements New Accounting Pronouncements

Recently Adopted Accounting Pronouncements
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
Accounting Standard Update (ASU) 2018-16 Derivatives and Hedging Inclusion of the Secured Overnight Financing Rate (SOFR) Overnight Index Swap (OIS) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes
In October 2018, the FASB issued amendments to permit use of the Overnight Index Swap (OIS) rate based on the Secured Overnight Financing Rate (SOFR) as a U.S. benchmark interest rate for hedge accounting purposes under Topic 815 in addition to the Treasury obligations of the U.S. government (UST), the London Interbank Offered Rate (LIBOR) swap rate, the OIS rate based on the Fed Funds Effective Rate, and the Securities Industry and Financial Markets Association (SIFMA) Municipal Swap Rate.
Early adopted as of October 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations or disclosures.
ASU 2018-03
Technical Corrections and Improvements to Financial Instruments - Overall Recognition and Measurement of Financial Assets and Financial Liabilities
In February 2018, the FASB issued amendments to clarify certain aspects of the guidance issued in the original Financial Instruments - Overall - Recognition and Measurement pronouncement summarized below. Specifically, for entities who have chosen the measurement alternative approach for equity securities without readily determinable fair values, the amendments clarify that entities may change from a measurement alternative approach to a fair value method through an irrevocable election that would apply to a specific equity security and all identical or similar investments of the same issuer; entities should use an observable price at the date of the transaction rather than reporting date for the measurement alternative calculation; and insurance companies should use a prospective transition method when applying the measurement alternative.
Early adopted as of January 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations, or disclosures.
ASU 2018-02 
Income Statement - Reporting Comprehensive Income: Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income
In February 2018, the FASB issued amendments which allow a reclassification from accumulated other comprehensive income (AOCI) to retained earnings of the effects of the change in the U.S. federal income tax rate resulting from the Tax Cuts and Jobs Act (Tax Act) on the gross deferred tax amounts and the corresponding valuation allowances related to items remaining in AOCI. The amendments eliminate the stranded tax effects resulting from the Tax Act and also require certain disclosures about the reclassified tax effects.
Early adopted as of January 1, 2018
The amounts reclassified from
AOCI to retained earnings include the income tax effects of the change in the federal corporate tax rate enacted by the Tax Act. The Company’s policy is to follow the portfolio approach for releasing income tax effects from AOCI. The adoption of this guidance resulted in an increase to beginning 2018 AOCI of $374 million with a corresponding decrease to beginning 2018 retained earnings as of January 1, 2018.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2017-12
Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities
In August 2017, the FASB issued guidance which improves and simplifies the accounting rules around hedge accounting and creates more transparency around how economic results are presented in financial statements. Issues addressed in this new guidance include: 1) risk component hedging, 2) accounting for the hedged item in fair value hedges of interest rate risk, 3) recognition and presentation of the effects of hedging instruments, and 4) amounts excluded from the assessment of hedge effectiveness.
Early adopted as of October 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-09 Compensation - Stock Compensation: Scope of Modification Accounting
In May 2017, the FASB issued amendments to provide guidance clarifying when changes to the terms or conditions of a share-based payment award must be accounted for as modifications. An entity should apply modification accounting if the fair value, vesting conditions or classification of the award (as an equity instrument or liability instrument) changes as a result of the change in terms or conditions of the award.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-08 
Receivables - Nonrefundable Fees and Other Costs: Premium Amortization on Purchased Callable Debt Securities

In March 2017, the FASB issued amendments to shorten the amortization period for certain callable debt securities held at a premium. Specifically, the amendments require the premium to be amortized to the earliest call date. The amendments do not require an accounting change for securities held at a discount.
Early adopted as of July 1, 2018
The adoption of this guidance did not have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2017-07 
Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost
In March 2017, the FASB issued amendments requiring that an employer report the service cost component of net periodic pension cost and net periodic postretirement benefit cost in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net periodic pension cost and net periodic postretirement benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. If a separate line item or items are used to present the other components of net benefit cost, that line item or items must be appropriately described. If a separate line item or items are not used, the line item or items used in the income statement to present the other components of net benefit cost must be disclosed. The amendments in this update also allow only the service cost component to be eligible for capitalization when applicable.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2017-05
Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets: Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets
In February 2017, the FASB issued amendments that clarify the scope and accounting guidance for the derecognition of a nonfinancial asset or a financial asset that meets the definition of an "in substance nonfinancial asset." The amendments define an "in substance nonfinancial asset" and provide additional accounting guidance for partial sales of nonfinancial assets.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-01
Business Combinations: Clarifying the Definition of a Business
In January 2017, the FASB issued amendments clarifying when a set of assets and activities is a business. The amendments provide a screen to exclude transactions where substantially all the fair value of the transferred set is concentrated in a single asset, or group of similar assets, from being evaluated as a business.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-18 
Statement of Cash Flows: Restricted Cash
In November 2016, the FASB issued amendments requiring that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, statements of cash flows, or disclosures.
ASU 2016-17
Consolidation - Interests Held through Related Parties That Are under Common Control
In October 2016, the FASB issued amendments which clarify the consolidation guidance on how a reporting entity that is the single decision maker of a variable interest entity (VIE) should treat indirect interests in the entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of that VIE.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-16 
Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory
In October 2016, the FASB issued amendments that require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-15 Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments
In August 2016, the FASB issued amendments that provide guidance on eight specific statement of cash flow classification issues, including distributions received from equity method investees.
January 1, 2018
The Company elected nature of distribution for distributions received from equity method investees. The adoption of this guidance did not have a significant impact on the Company's financial position, statement of cash flows, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2016-09
Compensation - Stock Compensation: Improvements to Employee Share-Based Payment Accounting

In March 2016, the FASB issued amendments which simplify several aspects for share-based payment award transactions, including the income tax consequences, classification of awards as either liability or equity, classification of taxes paid on the statement of cash flows and treatment of forfeitures.


January 1, 2017
As a result of applying this requirement, the Company believes that recognition of excess tax benefits will increase volatility in its statement of operations and the Company made an entity-wide accounting policy election to estimate the number of awards that are expected to vest (consistent with the Company's prior policy), but the adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, statements of cash flows, or disclosures.
ASU 2016-07
Investments - Equity Method and Joint Ventures - Simplifying the Transition to the Equity Method of
Accounting
In March 2016, the FASB issued amendments which eliminate the requirement that when an investment
qualifies for use of the equity method as a result of an increase in the level of ownership interest or degree of influence, an investor must adjust the investment, results of operations, and retained earnings retroactively on a step-by-step basis as if the equity method had been in effect during all previous periods that the investment had been held. Per the amendments, upon qualifying for the equity method of accounting, no retroactive adjustment of the investment is required.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-06
Derivatives and Hedging - Contingent Put and Call Options in Debt Instruments
In March 2016, the FASB issued amendments which clarify what steps are required when assessing whether the economic characteristics and risks of call (put) options are clearly and closely related to the economic characteristics and risks of their debt hosts, which is one of the criteria for bifurcating an embedded derivative. Consequently, when a call (put) option is contingently exercisable, an entity does not have to assess whether the event that triggers the ability to exercise a call (put) option is related to interest rates or credit risks.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2016-05
Derivatives and Hedging - Effect of Derivative Contract Novations on Existing Hedge Accounting
Relationships
In March 2016, the FASB issued amendments which clarify that a change in the counterparty to a derivative instrument that has been designated as the hedging instrument does not, in and of itself, require dedesignation of that hedging relationship provided that all other hedge accounting criteria remain intact.
January 1, 2017
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2016-01 
Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities
In January 2016, the FASB issued guidance to address certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. The main provisions of this guidance require certain equity investments to be measured at fair value with changes in fair value recognized in net earnings; separate presentation in other comprehensive income for changes in fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk; and changes in disclosures associated with the fair value of financial instruments. The guidance also clarifies that entities should evaluate the need for a valuation allowance on a deferred tax asset (DTA) related to available-for-sale (AFS) securities in combination with the entity's other DTAs.
January 1, 2018
The Company recorded a cumulative effect adjustment with an increase to beginning 2018 retained earnings and a decrease to beginning 2018 AOCI of $148 million, net of taxes.
ASU 2015-16
Business Combinations - Simplifying the Accounting for Measurement-Period Adjustments
In September 2015, the FASB issued guidance requiring that an acquirer recognize adjustments to estimated amounts that are identified during the measurement period in the reporting period in which the adjustments are determined. In the same period’s financial statements, the acquirer is required to record income effects of the adjustments as if the accounting had been completed at the acquisition date. The acquirer is also required to present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the estimated amounts had been recognized as of the acquisition date.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2015-09
Financial Services - Insurance - Disclosures about Short-Duration Contracts
In May 2015, the FASB issued updated guidance requiring enhanced disclosures by all insurance entities that issue short-duration contracts. The amendments require insurance entities to disclose for annual reporting periods information about the liability for unpaid claims and claim adjustment expenses. The amendments also require insurance entities to disclose information about significant changes in methodologies and assumptions used to calculate the liability for unpaid claims and claim adjustment expenses. In addition, the amendments require insurance entities to disclose for annual and interim reporting periods a roll-forward of the liability for unpaid claims and claim adjustment expenses. For health insurance claims, the amendments require the disclosure of the total of incurred-but-not-reported liabilities and expected development on reported claims included in the liability for unpaid claims and claim adjustment expenses.
December 31, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2015-07
Fair Value Measurement - Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)
In May 2015, the FASB issued updated guidance that removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The amendments also remove the requirement to make certain disclosures for all investments that are eligible to be measured at fair value using the net asset value per share practical expedient. Rather, those disclosures are limited to investments for which the entity has elected to measure the fair value using that practical expedient.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2015-03
Interest - Imputation of Interest - Simplifying the Presentation of Debt Issuance Costs
In April 2015, the FASB issued updated guidance to simplify presentation of debt issuance costs. The updated guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this amendment. In August 2015, the FASB issued updated Securities and Exchange Commission (SEC) Staff guidance pertaining to the presentation of debt issuance costs related to line-of-credit arrangements. The guidance states that an entity may defer and present debt issuance costs as an asset, subsequently amortizing the deferred debt issuance costs ratably over the term of the line-of-credit arrangement, regardless of whether there are any outstanding borrowings on the line-of-credit arrangement.
January 1, 2016
The retrospective adoption of this accounting standard resulted in a $40 million reduction to notes payable and other assets as of December 31, 2015, the earliest balance sheet date presented in the period of adoption, but did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2015-02
Consolidation - Amendments to the Consolidation Analysis
In February 2015, the FASB issued updated guidance that affects evaluation of whether limited partnerships and similar legal entities (limited liability corporations and securitization structures, etc.) are VIEs, evaluation of whether fees paid to a decision maker or a service provider are a variable interest, and evaluation of the effect of fee arrangements and the effect of related parties on the determination of the primary beneficiary under the VIE model for consolidation. The updated guidance eliminates the presumption that a general partner should consolidate a limited partnership. Limited partnership and similar legal entities that provide partners with either substantive kick-out rights or substantive participating rights over the general partner will now be evaluated under the voting interest model rather than the VIE model for consolidation. In situations where no single party has a controlling financial interest in a VIE, the related party relationships under common control should be considered in their entirety in determining whether that common control group has a controlling financial interest in the VIE.
January 1, 2016
The adoption of this guidance impacted the Company's footnote disclosures, but did not have a significant impact on its financial position or results of operations.

ASU 2014-16
Derivatives and Hedging - Determining Whether the Host Contract in a Hybrid Financial Instrument Issued in the Form of a Share Is More Akin to Debt or to Equity
In November 2014, the FASB issued guidance to clarify how to evaluate the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The guidance also clarifies that an entity should assess the substance of the relevant terms and features when considering how to weight those terms and features.
January 1, 2016
The adoption of this guidance impacted the Company's footnote disclosures, but did not have a significant impact on its financial position or results of operations.

ASU 2014-15
Presentation of Financial Statements - Going Concern - Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern
In August 2014, the FASB issued this amendment that provides U.S. GAAP guidance on management’s responsibility in evaluating whether there is substantial doubt about a company’s ability to continue as a going concern and about related footnote disclosures. For each reporting period, management will be required to evaluate whether there are conditions or events that raise substantial doubt about a company’s ability to continue as a going concern within one year from the date the financial statements are issued. The new guidance requires a formal assessment of going concern by management based on criteria prescribed in the new guidance.
December 31, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations or disclosures and no substantial doubt currently exists about the Company's ability to continue as a going concern.
Standard
Description
Date of Adoption
Effect on Financial Statements or Other Significant Matters
ASU 2014-12
Compensation - Stock Compensation - Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period
In June 2014, the FASB issued this amendment that provides guidance on certain share-based payment awards that require a specific performance target that affects vesting and that could be achieved after the requisite service period be treated as a performance condition. A reporting entity should apply existing guidance to awards with performance conditions that affect vesting to account for such awards. Compensation cost should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. The total amount of compensation cost recognized during and after the requisite service period should reflect the number of awards that are expected to vest and should be adjusted to reflect those awards that ultimately vest.
January 1, 2016
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2014-09
Revenue from Contracts with Customers
In May 2014, the FASB issued updated guidance that affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). The core principle of the guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.
January 1, 2018
The adoption of this guidance did not have a significant impact on the Company's financial position, results of operations, or disclosures.
Description of Accounting Pronouncements Pending Adoption Accounting Pronouncements Pending Adoption
Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-20 Leases: Narrow-Scope Improvements for Lessors
In December 2018, the FASB issued narrow-scope improvements for lessors which 1) provide an accounting policy election for lessors to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price; 2) require lessors to exclude the costs from variable lease revenue and the associated expense when the amount of those costs is not readily determinable by the lessor; and 3) require lessors to allocate (rather than recognize) certain variable payments to the lease and nonlease components when the changes in facts and circumstances on which the variable payment is based occur. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted.
The Company has made an accounting policy election to exclude amounts collected from customers for all sales (and other similar) taxes from the transaction price. The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-17 Consolidation: Targeted Improvements to Related Party Guidance for Variable Interest Entities
In October 2018, the FASB issued targeted improvements which provide that indirect interests held through related parties under common control should be considered on a proportional basis for determining whether fees paid to decision makers and service providers are variable interests. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations or disclosures.
ASU 2018-15
Intangibles - Goodwill and Other - Internal-Use Software, Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract
In August 2018, the FASB issued amendments to align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted.

The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations or disclosures.

ASU 2018-14
Compensation - Retirement Benefits - Defined Benefit Plans - General, Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans
In August 2018, the FASB issued amendments to modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. Accordingly, six disclosure requirements were removed, two added and two clarified. The amendments are effective for public business entities for fiscal years beginning after December 15, 2020. Early adoption is permitted.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-13
Fair Value Measurement, Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement
In August 2018, the FASB issued amendments to the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement. The amendments remove, modify, and add certain disclosures. The amendments are effective for all entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted upon issuance of this Update. An entity is permitted to early adopt any removed or modified disclosures upon issuance of this update and delay adoption of the additional disclosures until their effective date.
The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-12
Financial Services - Insurance, Targeted Improvements to the Accounting for Long-Duration Contracts

In August 2018, the FASB issued amendments that will significantly change how insurers account for long-duration contracts. The amendments will change existing recognition, measurement, presentation, and disclosure requirements. Issues addressed in the new guidance include: 1) a requirement to review and, if there is a change, update assumptions for the liability for future policy benefits at least annually, and to update the discount rate assumption quarterly, 2) accounting for market risk benefits at fair value, 3) simplified amortization for deferred acquisition costs, and 4) enhanced financial statement presentation and disclosures. The amendments are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. Early application of the amendments is permitted.

The Company is thoroughly evaluating the impact of adoption and expects that the adoption will have a significant impact on the Company’s financial position, results of operations, and disclosures. The Company anticipates that the requirement to update assumptions for liability for future policy benefits will have a significant impact on its results of operations, systems, processes and controls while the requirement to update the discount rate will have a significant impact on its equity. The Company does not expect to early adopt the updated standard.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2018-11
Leases, Targeted Improvements

In July 2018, the FASB issued targeted improvements to Topic 842 Leases. The amendments in the update provide entities with an optional transition method to adopt the new leases standard by recording a cumulative effect adjustment to beginning retained earnings. Additionally, the amendments provide lessors with a practical expedient to not separate nonlease components from associated lease components and instead account for those components as a single component under certain conditions. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted.
The Company has elected the optional transition method. The adoption of this guidance is not expected to have a significant impact on the Company’s financial position, results of operations, or disclosures.

ASU 2018-10
Codification Improvements to Topic 842, Leases

In July 2018, the FASB issued guidance which clarifies, corrects errors in, or makes minor improvements to the Codification related to ASU 2016-02, Leases (Topic 842). The amendments in this ASU affect narrow aspects of the guidance issued in the amendments to ASU 2016-02, including but not limited to, Residual Value Guarantees, Rate Implicit in the Lease, Lessee Reassessment of Lease Classification and Variable Lease Payments that Depend on an Index or a Rate. Amendments within this ASU follow the effective dates of Topic 842, which are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years.
The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2018-01
Leases: Land Easement Practical Expedient for Transition to Topic 842
In January 2018, the FASB issued guidance which provides an entity with the option to elect a transition practical expedient to not evaluate, under Topic 842, land easements that exist or expired before the entity's adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. The amendments clarify that new or modified land easements should be evaluated under the new leases standard once an entity has adopted the new standard. The amendments are effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption is permitted.
As of December 31, 2018, the Company did not have land easements, but has elected this practical expedient as a safe harbor. The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.
ASU 2017-04
Intangibles - Goodwill and Other: Simplifying the Test for Goodwill Impairment
In January 2017, the FASB issued amendments simplifying the subsequent measurement of goodwill. An entity is no longer required to perform a hypothetical purchase price allocation to measure goodwill impairment. Instead, the entity should perform its annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. The amendments are effective for public business entities that are SEC filers for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for any goodwill impairment tests performed on testing dates after January 1, 2017.
The adoption of this guidance is not expected to have a significant impact on the Company's financial position, results of operations, or disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2016-13
Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Instruments
In June 2016, the FASB issued amendments that require a financial asset (or a group of financial assets) measured on an amortized cost basis to be presented net of an allowance for credit losses in order to reflect the amount expected to be collected on the financial asset(s). The measurement of expected credit losses is amended by replacing the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform about a credit loss. Credit losses on available-for-sale debt securities will continue to be measured in a manner similar to current U.S. GAAP; however, the amendments require that credit losses be presented as an allowance rather than as a write-down. Other amendments include changes to the balance sheet presentation and interest income recognition of purchased financial assets with a more-than-insignificant amount of credit deterioration since origination (PCD financial assets). The amendments are effective for public companies for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Companies may early adopt this guidance as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. The amendments will be adopted following a modified-retrospective approach resulting in a cumulative effect adjustment in retained earnings as of the beginning of the year of adoption. Two exceptions to this adoption method are for PCD financial assets and debt securities for which other-than-temporary impairment (OTTI) will have been recognized before the effective date. Loans purchased with credit deterioration accounted for under current U.S. GAAP as "purchased credit impaired" (PCI) financial assets will be classified as PCD financial assets at transition and PCD guidance will be applied prospectively. Debt securities that have experienced OTTI before the effective date will follow a prospective adoption method which allows an entity to maintain the same amortized cost basis before and after the effective date.
The Company has identified certain financial instruments in scope of this guidance to include certain fixed maturity securities, loans and loan receivables and reinsurance recoverables (See Notes 3 and 7 for current balances of instruments in scope). The Company is continuing its progress towards updating its credit loss projection models and accounting systems in order to comply with the required changes in measurement of credit losses. The Company currently expects loans and loan receivables and held-to-maturity fixed maturity securities to be the asset classes most significantly impacted upon adoption of the guidance. The Company continues to evaluate the impact of adoption of this guidance on its financial position, results of operations, and disclosures.

Standard
Description
Effect on Financial Statements or Other Significant Matters
ASU 2016-02
Leases
In February 2016, the FASB issued updated guidance for accounting for leases. Per the amendments, lessees will be required to recognize all leases on the balance sheet with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new standard is effective for the Company on January 1, 2019. A modified retrospective transition approach is required, applying the new standard to all leases existing at the date of initial application. The Company is electing to use its effective date as its date of initial application. Because the Company expects to adopt the new standard on January 1, 2019 and use the effective date as the date of initial application, financial information is not required to be updated and the disclosures required under the new standard are not required to be provided for dates and periods before January 1, 2019. The new standard provides a number of optional practical expedients. The Company has elected the "package of practical expedients," which permits the Company not to reassess under the new standard its prior conclusions about lease identification, lease classification and initial direct costs. Under the new guidance, lessor accounting is largely unchanged. The amendments are effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period.
The Company has identified certain operating leases in scope of this guidance to include office space and equipment leases (See Note 15). The leases within scope of this guidance will increase the Company's right-of-use assets and lease liabilities recorded on its statement of financial position by approximately $100 to $200 million. The Company estimates that the adoption of this guidance will not have a significant impact on its financial position, results of operations, or disclosures.
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION (Tables)
 12 Months Ended
Dec. 31, 2018
Segment Reporting [Abstract]  
Reconciliation of Revenue from Segments to Consolidated Information regarding operations by segment for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
Revenues:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan:
 
 
 
 
 
 
 
 
 
 
 
   Net earned premiums:
 
 
 
 
 
 
 
 
 
 
 
             Cancer
 
$
5,849

 
 
 
$
5,612

 
 
 
$
5,639

 
             Medical and other health
 
3,516

 
 
 
3,379

 
 
 
3,429

 
             Life insurance
 
3,397

 
 
 
3,761

 
 
 
4,469

 
   Net investment income, less amortized hedge costs
 
2,403

 
 
 
2,235

 
 
 
2,368

 
   Other income
 
41

 
 
 
41

 
 
 
40

 
               Total Aflac Japan
 
15,206

 
 
 
15,028

 
 
 
15,945

 
Aflac U.S.:
 
 
 
 
 
 
 
 
 
 
 
   Net earned premiums:
 
 
 
 
 
 
 
 
 
 
 
             Accident/disability
 
2,611

 
 
 
2,537

 
 
 
2,469

 
             Cancer
 
1,311

 
 
 
1,308

 
 
 
1,299

 
             Other health
 
1,508

 
 
 
1,445

 
 
 
1,415

 
             Life insurance
 
278

 
 
 
273

 
 
 
271

 
   Net investment income
 
727

 
 
 
721

 
 
 
703

 
   Other income
 
8

 
 
 
5

 
 
 
10

 
           Total Aflac U.S.
 
6,443

 
 
 
6,289

 
 
 
6,167

 
Corporate and other
 
339

 
 
 
272

 
 
 
275

 
           Total adjusted revenues
 
21,988

 
 
 
21,589

 
 
 
22,387

 
Realized investment gains (losses) (1),(2),(3)
 
(230
)
 
 
 
78

 
 
 
172

 
           Total revenues
 
$
21,758

 
 
 
$
21,667

 
 
 
$
22,559

 

(1) Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from net investment income when analyzing segment operations.
(2) Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in net investment income when analyzing operations.
(3) An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
Reconciliation of Adjusted Profit (Loss) from Segments to Consolidated
(In millions)
2018
 
2017
 
2016
Pretax earnings:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
3,208

 
 
 
$
3,054

 
 
 
$
3,148

 
Aflac U.S.
 
1,285

 
 
 
1,245

 
 
 
1,208

 
Corporate and other
 
(139
)
 
 
 
(212
)
 
 
 
(239
)
 
    Pretax adjusted earnings
 
4,354

 
 
 
4,087

 
 
 
4,117

 
Realized investment gains (losses) (1),(2),(3),(4)
 
(297
)
 
 
 
0

 
 
 
87

 
Other income (loss) (5)
 
(74
)

 
 
(69
)
 
 
 
(137
)

    Total earnings before income taxes
 
$
3,983

 
 
 
$
4,018

 
 
 
$
4,067

 
Income taxes applicable to pretax adjusted earnings
 
$
1,129

 
 
 
$
1,370

 
 
 
$
1,426

 
Effect of foreign currency translation on after-tax
adjusted earnings
 
28

 
 
 
(41
)
 
 
 
141

 

(1) Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from pretax adjusted earnings when analyzing segment operations.
(2) Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in pretax adjusted earnings when analyzing operations.
(3) An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
(4) Excluding a gain of $67 in 2018, $77 in 2017 and $85 in 2016, related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is included in adjusted earnings when analyzing segment operations
(5) Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt

Reconciliation of Assets from Segment to Consolidated Assets as of December 31 were as follows:
(In millions)
2018
 
2017
 
Assets:
 
 
 
 
 
 
 
 
Aflac Japan
 
$
118,342

 
 
 
$
114,402

 
 
Aflac U.S.
 
19,100

 
 
 
19,893

 
 
Corporate and other
 
2,964

 
 
 
2,922

 
 
    Total assets
 
$
140,406

 
 
 
$
137,217

 
 
Foreign Currency Disclosure Yen-Translation Effects: The following table shows the yen/dollar exchange rates used for or during the periods ended December 31. Exchange effects were calculated using the same yen/dollar exchange rate for the current year as for each respective prior year.
 
2018
 
2017
 
2016
Statements of Earnings:
 
 
 
 
 
 
 
 
 
 
 
Weighted-average yen/dollar exchange rate(1)
 
110.39

 
 
 
112.16

 
 
 
108.70

 
Yen percent strengthening (weakening)
 
1.6
%
 
 
 
(3.1
)%
 
 
 
11.3
%
 
Exchange effect on pretax operating earnings (in millions)
 
$
38

 
 
 
$
(63
)
 
 
 
$
218

 

 
2018
 
2017
Balance Sheets:
 
 
 
 
 
 
 
Yen/dollar exchange rate at December 31(1)
 
111.00

 
 
 
113.00

 
Yen percent strengthening (weakening)
 
1.8
%
 
 
 
3.1
%
 
Exchange effect on total assets (in millions)
 
$
1,362

 
 
 
$
2,593

 
Exchange effect on total liabilities (in millions)
 
1,270

 
 
 
2,848

 

(1) Rates are based on the published MUFG Bank, Ltd. telegraphic transfer middle rate (TTM)
Schedule of Intercompany Transfers of Funds Information on transfers for each of the years ended December 31 is shown below. See Note 13 for information concerning restrictions on transfers from Aflac Japan.
(In millions)
2018
 
2017
 
2016
Management fees
 
$
136

 
 
 
$
93

 
 
 
$
79

 
Allocated expenses
 
24

 
 
 
109

 
 
 
106

 
Profit remittances
 
808

 
 
 
1,150

 
 
 
1,286

 
Total transfers from Aflac Japan
 
$
968

 
 
 
$
1,352

 
 
 
$
1,471

 
Property, Plant and Equipment Classes of property and equipment as of December 31 were as follows:
(In millions)
2018
 
2017
Property and equipment:
 
 
 
 
 
 
 
Land
 
$
168

 
 
 
$
168

 
Buildings
 
456

 
 
 
441

 
Equipment and furniture
 
400

 
 
 
372

 
Total property and equipment
 
1,024

 
 
 
981

 
Less accumulated depreciation
 
581

 
 
 
547

 
Net property and equipment
 
$
443

 
 
 
$
434

 
v3.10.0.1
INVESTMENTS (Tables)
 12 Months Ended
Dec. 31, 2018
Schedule Of Net Investment Income The components of net investment income for the years ended December 31 were as follows:
(In millions)
2018
 
2017
 
2016
Fixed maturity securities
 
$
3,142

 
 
 
$
3,173

 
 
 
$
3,308

 
Equity securities
 
38

 
 
 
42

 
 
 
35

 
Other investments
 
369

 
 
 
94

 
 
 
31

 
Short-term investments and cash equivalents
 
41

 
 
 
25

 
 
 
11

 
Gross investment income
 
3,590

 
 
 
3,334

 
 
 
3,385

 
Less investment expenses
 
148

 
 
 
114

 
 
 
107

 
Net investment income
 
$
3,442

 
 
 
$
3,220

 
 
 
$
3,278

 
Available-for-Sale Debt Securities The amortized cost for the Company's investments in fixed maturity securities, the cost for equity securities and the fair values of these investments at December 31 are shown in the following tables.
  
2018
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
  Fair
  Value
Securities available for sale, carried at fair value
through other comprehensive income:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
30,637

 
 
 
$
3,700

 
 
 
$
140

 
 
 
$
34,197

 
Municipalities
 
385

 
 
 
32

 
 
 
9

 
 
 
408

 
Mortgage- and asset-backed securities
 
155

 
 
 
22

 
 
 
0

 
 
 
177

 
Public utilities
 
1,732

 
 
 
280

 
 
 
4

 
 
 
2,008

 
Sovereign and supranational
 
826

 
 
 
123

 
 
 
0

 
 
 
949

 
Banks/financial institutions
 
5,440

 
 
 
502

 
 
 
238

 
 
 
5,704

 
Other corporate
 
4,852

 
 
 
649

 
 
 
44

 
 
 
5,457

 
Total yen-denominated
 
44,027

 
 
 
5,308

 
 
 
435

 
 
 
48,900

 
  U.S. dollar-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government and agencies
 
137

 
 
 
9

 
 
 
1

 
 
 
145

 
Municipalities
 
1,343

 
 
 
120

 
 
 
8

 
 
 
1,455

 
Mortgage- and asset-backed securities
 
155

 
 
 
8

 
 
 
1

 
 
 
162

 
Public utilities
 
4,772

 
 
 
496

 
 
 
105

 
 
 
5,163

 
Sovereign and supranational
 
251

 
 
 
60

 
 
 
0

 
 
 
311

 
Banks/financial institutions
 
2,860

 
 
 
389

 
 
 
35

 
 
 
3,214

 
Other corporate
 
23,311

 
 
 
1,343

 
 
 
1,109

 
 
 
23,545

 
Total U.S. dollar-denominated
 
32,829

 
 
 
2,425

 
 
 
1,259

 
 
 
33,995

 
Total securities available for sale
 
$
76,856

(1) 
 
 
$
7,733

 
 
 
$
1,694

 
 
 
$
82,895

(1) 

(1) Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
Held-to-Maturity Securities
  
2017
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
21,331

 
 
 
$
5,160

 
 
 
$
0

 
 
 
$
26,491

 
Municipalities
 
357

 
 
 
105

 
 
 
0

 
 
 
462

 
Mortgage- and asset-backed securities
 
26

 
 
 
1

 
 
 
0

 
 
 
27

 
Public utilities
 
3,300

 
 
 
398

 
 
 
0

 
 
 
3,698

 
Sovereign and supranational
 
1,523

 
 
 
312

 
 
 
0

 
 
 
1,835

 
Banks/financial institutions
 
2,206

 
 
 
190

 
 
 
9

 
 
 
2,387

 
Other corporate
 
2,687

 
 
 
485

 
 
 
0

 
 
 
3,172

 
Total yen-denominated
 
31,430

 
 
 
6,651

 
 
 
9

 
 
 
38,072

 
Total securities held to maturity
 
$
31,430

 
 
 
$
6,651

 
 
 
$
9

 
 
 
$
38,072

 
  
2018
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
Fair  
Value  
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
21,712

 
 
 
$
5,326

 
 
 
$
0

 
 
 
$
27,038

 
Municipalities
 
359

 
 
 
110

 
 
 
0

 
 
 
469

 
Mortgage- and asset-backed securities
 
14

 
 
 
1

 
 
 
0

 
 
 
15

 
Public utilities
 
2,727

 
 
 
254

 
 
 
8

 
 
 
2,973

 
Sovereign and supranational
 
1,551

 
 
 
289

 
 
 
0

 
 
 
1,840

 
Banks/financial institutions
 
1,445

 
 
 
158

 
 
 
20

 
 
 
1,583

 
Other corporate
 
2,510

 
 
 
332

 
 
 
38

 
 
 
2,804

 
Total yen-denominated
 
30,318

 
 
 
6,470

 
 
 
66

 
 
 
36,722

 
Total securities held to maturity
 
$
30,318

 
 
 
$
6,470

 
 
 
$
66

 
 
 
$
36,722

 
Equity Securities, FV-NI
  
2018
(In millions)
 
 
 
 
 
 
Fair  
Value  
Equity securities, carried at fair value through
net earnings:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Equity securities: (1) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Yen-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
$
641

 
      U.S. dollar-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
346

 
Total equity securities
 
 
 
 
 
 
 
 
 
 
 
 
 
$
987

(1) 
(1) Includes perpetual securities ($62 at fair value)
Available-for-sale Securities
  
2017
(In millions)
 
 
 
 
 
 
Fair
Value
Equity securities, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Equity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Yen-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
$
695

 
      U.S. dollar-denominated
 
 
 
 
 
 
 
 
 
 
 
 
 
328

 
Total equity securities
 
 
 
 
 
 
 
 
 
 
 
 
 
$
1,023

 
 
2017
(In millions)
Cost or
Amortized
Cost
 
Gross
Unrealized
Gains
 
Gross
Unrealized
Losses
 
  Fair
  Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Japan government and agencies
 
$
27,980

 
 
 
$
3,363

 
 
 
$
271

 
 
 
$
31,072

 
Municipalities
 
314

 
 
 
28

 
 
 
12

 
 
 
330

 
Mortgage- and asset-backed securities
 
242

 
 
 
29

 
 
 
0

 
 
 
271

 
Public utilities
 
1,635

 
 
 
352

 
 
 
6

 
 
 
1,981

 
Sovereign and supranational
 
1,380

 
 
 
190

 
 
 
1

 
 
 
1,569

 
Banks/financial institutions
 
4,742

 
 
 
811

 
 
 
53

 
 
 
5,500

 
Other corporate
 
4,085

 
 
 
809

 
 
 
7

 
 
 
4,887

 
Total yen-denominated
 
40,378

 
 
 
5,582

 
 
 
350

 
 
 
45,610

 
  U.S dollar-denominated:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S. government and agencies
 
146

 
 
 
13

 
 
 
1

 
 
 
158

 
Municipalities
 
872

 
 
 
168

 
 
 
0

 
 
 
1,040

 
Mortgage- and asset-backed securities
 
161

 
 
 
12

 
 
 
0

 
 
 
173

 
Public utilities
 
5,116

 
 
 
884

 
 
 
27

 
 
 
5,973

 
Sovereign and supranational
 
267

 
 
 
73

 
 
 
0

 
 
 
340

 
Banks/financial institutions
 
2,808

 
 
 
633

 
 
 
8

 
 
 
3,433

 
Other corporate
 
25,384

 
 
 
2,620

 
 
 
418

 
 
 
27,586

 
Total U.S. dollar-denominated
 
34,754

 
 
 
4,403

 
 
 
454

 
 
 
38,703

 
Total securities available for sale
 
$
75,132

(1) 
 
 
$
9,985

 
 
 
$
804

 
 
 
$
84,313

(1) 

(1) Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
Investments Classified by Contractual Maturity Date The contractual maturities of the Company's investments in fixed maturity securities at December 31, 2018, were as follows:
(In millions)
Amortized
Cost
 
Fair
Value
Available for sale: (1)
 
 
 
 
 
 
Due in one year or less
 
$
810

 
 
 
$
861

Due after one year through five years
 
8,313

 
 
 
8,312

Due after five years through 10 years
 
9,805

 
 
 
10,355

Due after 10 years
 
57,618

 
 
 
63,028

Mortgage- and asset-backed securities
 
310

 
 
 
339

Total fixed maturity securities available for sale
 
$
76,856

 
 
 
$
82,895

Held to maturity:
 
 
 
 
 
 
Due in one year or less
 
$
180

 
 
 
$
182

Due after one year through five years
 
915

 
 
 
948

Due after five years through 10 years
 
927

 
 
 
1,004

Due after 10 years
 
28,282

 
 
 
34,573

Mortgage- and asset-backed securities
 
14

 
 
 
15

Total fixed maturity securities held to maturity
 
$
30,318

 
 
 
$
36,722


(1) Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
Investment Exposures Exceeding 10 Percent Shareholders Equity Investment exposures that individually exceeded 10% of shareholders' equity as of December 31 were as follows:
 
2018
 
2017
(In millions)
Credit
Rating
 
Amortized
Cost
 
Fair
Value
 
Credit
Rating
 
Amortized
Cost
 
Fair
Value
Japan National Government(1)
A+
 
$51,207
 
$59,945
 
A
 
$48,399
 
$56,532
(1)Japan Government Bonds (JGBs) or JGB-backed securities
Gain (Loss) on Investments Information regarding pretax realized gains and losses from investments for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
 
Realized investment gains (losses):
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
Available for sale:
 
 
 
 
 
 
Gross gains from sales
$
101

 
$
51

 
$
177

 
Gross losses from sales
(156
)
 
(68
)
 
(62
)
 
Foreign currency gains (losses) on sales and redemptions
73

 
(48
)
 
4

 
Other-than-temporary impairment losses
(64
)
 
(7
)
 
(26
)
 
Total fixed maturity securities
(46
)
 
(72
)
 
93

 
Equity securities (1),(2)
(131
)
 
71

(3) 
(35
)
(3) 
Loan receivables:
 
 
 
 
 
 
Loan loss reserves
(17
)
 
(8
)
 
(2
)
 
Other gains (losses) on loans
(2
)
 
0

 
0

 
Total loan receivables
(19
)
 
(8
)
 
(2
)
 
Derivatives and other:
 
 
 
 
 
 
Derivative gains (losses)
(224
)
 
(109
)
 
(255
)
 
Foreign currency gains (losses)
(10
)
 
(33
)
 
185

 
Total derivatives and other
(234
)
 
(142
)
 
(70
)
 
Total realized investment gains (losses)
$
(430
)
 
$
(151
)
 
$
(14
)
 

(1) Includes perpetual securities
(2) See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
(3) Includes impairments of $22 in 2017 and $57 in 2016
Unrealized Gain (Loss) on Investments Information regarding changes in unrealized gains and losses from investments recorded in AOCI for the years ended December 31 follows:
(In millions)
2018
 
2017
 
2016
Changes in unrealized gains (losses):
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
(3,142
)
 
 
 
$
1,657

 
 
 
$
2,711

 
Equity securities (2)
 
0

 
 
 
71

 
 
 
88

 
Total change in unrealized gains (losses)
 
$
(3,142
)
 
 
 
$
1,728

 
 
 
$
2,799

 

(1) Includes perpetual securities
(2) See Note 1 and Note 11 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance and the cumulative effect of the change in accounting principle related to financial instruments effective January 1, 2018.
Net Effect on Shareholders' Equity of Unrealized Gains and Losses from Investment Securities The net effect on shareholders' equity of unrealized gains and losses from investment securities at December 31 was as follows:
(In millions)
2018
 
2017
Unrealized gains (losses) on securities available for sale
 
$
6,039

 
 
 
$
9,358

 
Deferred income taxes
 
(1,805
)
 
 
 
(3,394
)
 
Shareholders’ equity, unrealized gains (losses) on investment securities
 
$
4,234

 
 
 
$
5,964

 

See Notes 1 and 10 for discussion of the accounting treatment of tax on amounts recorded in accumulated other comprehensive income pursuant to the Tax Act and Note 1 for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
Investments Gross Unrealized Loss Aging The following tables show the fair values and gross unrealized losses of the Company's available-for-sale and held-to-maturity investments that were in an unrealized loss position, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position at December 31.
 
  
2018
  
Total
 
Less than 12 months
 
12 months or longer
(In millions)
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
$
67

 
 
 
$
1

 
 
 
$
67

 
 
 
$
1

 
 
 
$
0

 
 
 
$
0

 
  Japan government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
3,604

 
 
 
140

 
 
 
3,604

 
 
 
140

 
 
 
0

 
 
 
0

 
  Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
515

 
 
 
8

 
 
 
515

 
 
 
8

 
 
 
0

 
 
 
0

 
  Yen-denominated
 
148

 
 
 
9

 
 
 
148

 
 
 
9

 
 
 
0

 
 
 
0

 
Mortgage- and asset-
backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
74

 
 
 
1

 
 
 
74

 
 
 
1

 
 
 
0

 
 
 
0

 
  Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
1,585

 
 
 
105

 
 
 
892

 
 
 
48

 
 
 
693

 
 
 
57

 
  Yen-denominated
 
604

 
 
 
12

 
 
 
604

 
 
 
12

 
 
 
0

 
 
 
0

 
  Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
625

 
 
 
35

 
 
 
340

 
 
 
19

 
 
 
285

 
 
 
16

 
  Yen-denominated
 
3,057

 
 
 
258

 
 
 
3,057

 
 
 
258

 
 
 
0

 
 
 
0

 
  Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
12,899

 
 
 
1,109

 
 
 
5,782

 
 
 
407

 
 
 
7,117

 
 
 
702

 
  Yen-denominated
 
1,306

 
 
 
82

 
 
 
1,306

 
 
 
82

 
 
 
0

 
 
 
0

 
  Total
 
$
24,484

 
 
 
$
1,760

 
 
 
$
16,389

 
 
 
$
985

 
 
 
$
8,095

 
 
 
$
775

 

(1) Includes perpetual securities



  
2017
  
Total
 
Less than 12 months
 
12 months or longer
(In millions)
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
 
Fair
Value
 
Unrealized
Losses
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
$
74

 
 
 
$
1

 
 
 
$
74

 
 
 
$
1

 
 
 
$
0

 
 
 
$
0

 
  Japan government and
agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
5,255

 
 
 
271

 
 
 
1,264

 
 
 
9

 
 
 
3,991

 
 
 
262

 
  Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
129

 
 
 
12

 
 
 
10

 
 
 
0

 
 
 
119

 
 
 
12

 
  Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
785

 
 
 
27

 
 
 
221

 
 
 
3

 
 
 
564

 
 
 
24

 
  Yen-denominated
 
83

 
 
 
6

 
 
 
0

 
 
 
0

 
 
 
83

 
 
 
6

 
  Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Yen-denominated
 
309

 
 
 
1

 
 
 
309

 
 
 
1

 
 
 
0

 
 
 
0

 
  Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
362

 
 
 
8

 
 
 
316

 
 
 
5

 
 
 
46

 
 
 
3

 
  Yen-denominated
 
1,507

 
 
 
62

 
 
 
394

 
 
 
4

 
 
 
1,113

 
 
 
58

 
  Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  U.S. dollar-denominated
 
7,741

 
 
 
418

 
 
 
2,839

 
 
 
50

 
 
 
4,902

 
 
 
368

 
  Yen-denominated
 
440

 
 
 
7

 
 
 
349

 
 
 
4

 
 
 
91

 
 
 
3

 
  Total
 
$
16,685

 
 
 
$
813

 
 
 
$
5,776

 
 
 
$
77

 
 
 
$
10,909

 
 
 
$
736

 

(1) Includes perpetual securities
Other Investments Other Investments

The table below reflects the composition of the carrying value for other investments as of December 31.
(In millions)
2018
 
2017
Other investments:
 
 
 
 
 
 
 
Transitional real estate loans
 
$
4,377

 
 
 
$
1,235

 
Commercial mortgage loans
 
1,064

 
 
 
908

 
Middle market loans
 
1,478

 
 
 
859

 
Policy loans
 
232

 
 
 
210

 
Short-term investments
 
152

 
 
 
57

 
Other
 
403

 
 
 
133

 
Total other investments
 
$
7,706

 
 
 
$
3,402

 
Securities Lending Transactions Accounted for as Secured Borrowings Details of our securities lending activities as of December 31 were as follows:
Securities Lending Transactions Accounted for as Secured Borrowings
2018
Remaining Contractual Maturity of the Agreements
(In millions)
Overnight
and
Continuous(1)
 
Up to 30
days
 
Greater
than 90
days
 
Total
Securities lending transactions:
 
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
 
Japan government and agencies
$
0

 
$
387

 
$
1,190

 
$
1,577

Municipalities
5

 
0

 
0

 
5

Public utilities
27

 
0

 
0

 
27

Banks/financial institutions
74

 
0

 
0

 
74

Other corporate
549

 
0

 
0

 
549

Equity securities
10

 
0

 
0

 
10

          Total borrowings
$
665

 
$
387

 
$
1,190

 
$
2,242

Gross amount of recognized liabilities for securities lending transactions
 
 
$
1,052

Amounts related to agreements not included in offsetting disclosure in Note 4
 
 
$
1,190

(1) These securities are pledged as collateral under the Company's U.S. securities lending program and can be called at its discretion; therefore, they are classified as Overnight and Continuous.
Securities Lending Transactions Accounted for as Secured Borrowings
2017
Remaining Contractual Maturity of the Agreements
(In millions)
Overnight
and
Continuous(1)
 
Up to 30
days
 
 
Total
Securities lending transactions:
 
 
 
 
 
 
Fixed maturity securities:
 
 
 
 
 
 
Japan government and agencies
$
0

 
$
49

 
 
$
49

Public utilities
73

 
0

 
 
73

Banks/financial institutions
54

 
0

 
 
54

Other corporate
415

 
0

 
 
415

Equity securities
15

 
0

 
 
15

          Total borrowings
$
557

 
$
49

 
 
$
606

Gross amount of recognized liabilities for securities lending transactions
 
$
606

Amounts related to agreements not included in offsetting disclosure in Note 4
 
$
0


(1) These securities are pledged as collateral under the Company's U.S. securities lending program and can be called at its discretion; therefore, they are classified as Overnight and Continuous.
Variable Interest Entity, Consolidated  
Investments in Variable Interest Entities The following table presents the cost or amortized cost, fair value and balance sheet caption in which the assets and liabilities of consolidated VIEs are reported as of December 31.
Investments in Consolidated Variable Interest Entities
  
2018
 
2017
(In millions)
Cost or Amortized
Cost
 
Fair
Value
 
Cost or Amortized
Cost
 
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
3,849

 
 
 
$
4,466

 
 
 
$
4,538

 
 
 
$
5,509

 
Equity securities
 
160

 
 
 
160

 
 
 
606

 
 
 
753

 
Other investments (2)
 
5,856

 
 
 
5,834

 
 
 
2,341

 
 
 
2,328

 
Other assets (3)
 
182

 
 
 
182

 
 
 
151

 
 
 
151

 
Total assets of consolidated VIEs
 
$
10,047

 
 
 
$
10,642

 
 
 
$
7,636

 
 
 
$
8,741

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities (3)
 
$
102

 
 
 
$
102

 
 
 
$
128

 
 
 
$
128

 
Total liabilities of consolidated VIEs
 
$
102

 
 
 
$
102

 
 
 
$
128

 
 
 
$
128

 

(1) Includes perpetual securities
(2) Consists of TREs, CMLs, MMLs, and alternative investments in limited partnerships
(3) Consists entirely of derivatives
Variable Interest Entity, Not Consolidated  
Investments in Variable Interest Entities The table below reflects the amortized cost, fair value and balance sheet caption in which the Company's investment in VIEs not consolidated are reported as of December 31.

Investments in Variable Interest Entities Not Consolidated
 
2018
 
2017
(In millions)
Amortized
Cost
 
Fair
Value
 
Amortized
Cost
 
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities, available for sale (1)
 
$
4,575

 
 
 
$
4,982

 
 
 
$
5,004

 
 
 
$
5,724

 
Fixed maturity securities, held to maturity
 
2,007

 
 
 
2,254

 
 
 
2,549

 
 
 
2,929

 
Other investments
 
49

 
 
 
49

 
 
 
55

 
 
 
55

 
Total investments in VIEs not consolidated
 
$
6,631

 
 
 
$
7,285

 
 
 
$
7,608

 
 
 
$
8,708

 

(1) Includes perpetual securities
v3.10.0.1
DERIVATIVE INSTRUMENTS (Tables)
 12 Months Ended
Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value

2018
 
2017
(In millions)
 
 
 
 
Asset
Derivatives
 
Liability
Derivatives
 
 
Asset
Derivatives
 
Liability
Derivatives
Hedge Designation/ Derivative
Type
Notional
Amount
 
Fair Value
 
Fair Value
Notional
Amount
 
Fair Value
 
Fair Value
Cash flow hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
75

 
 
 
$
1

 
 
 
$
(4
)
 
 
$
75

 
 
 
$
0

 
 
 
$
(8
)
 
Total cash flow hedges
 
75

 
 
 
1

 
 
 
(4
)
 
 
75

 
 
 
0

 
 
 
(8
)
 
Fair value hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency forwards
 
2,086

 
 
 
0

 
 
 
(34
)
 
 
7,640

 
 
 
2

 
 
 
(221
)
 
Foreign currency options
 
9,070

 
 
 
3

 
 
 
(1
)
 
 
7,670

 
 
 
0

 
 
 
(2
)
 
Interest rate swaptions
 
500

 
 
 
0

 
 
 
(1
)
 
 
0

 
 
 
0

 
 
 
0

 
Total fair value hedges
 
11,656

 
 
 
3

 
 
 
(36
)
 
 
15,310

 
 
 
2

 
 
 
(223
)
 
Net investment hedge:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency forwards
 
0

 
 
 
0

 
 
 
0

 
 
5

 
 
 
0

 
 
 
0

 
Foreign currency options
 
0

 
 
 
0

 
 
 
0

 
 
434

 
 
 
12

 
 
 
(1
)
 
Total net investment hedge
 
0

 
 
 
0

 
 
 
0

 
 
439

 
 
 
12

 
 
 
(1
)
 
Non-qualifying strategies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
5,387

 
 
 
284

 
 
 
(230
)
 
 
5,386

 
 
 
296

 
 
 
(189
)
 
Foreign currency forwards
 
16,057

 
 
 
126

 
 
 
(117
)
 
 
3,683

 
 
 
20

 
 
 
(53
)
 
Foreign currency options
 
430

 
 
 
0

 
 
 
0

 
 
770

 
 
 
0

 
 
 
0

 
Credit default swaps
 
0

 
 
 
0

 
 
 
0

 
 
88

 
 
 
1

 
 
 
0

 
Interest rate swaps
 
4,750

 
 
 
3

 
 
 
0

 
 
0

 
 
 
0

 
 
 
0

 
Total non-qualifying strategies
 
26,624

 
 
 
413

 
 
 
(347
)
 
 
9,927

 
 
 
317

 
 
 
(242
)
 
Total derivatives
 
$
38,355

 
 
 
$
417

 
 
 
$
(387
)
 
 
$
25,751

 
 
 
$
331

 
 
 
$
(474
)
 
Balance Sheet Location
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other assets
 
$
23,713

 
 
 
$
417

 
 
 
$
0

 
 
$
10,948

 
 
 
$
331

 
 
 
$
0

 
Other liabilities
 
14,642

 
 
 
0

 
 
 
(387
)
 
 
14,803

 
 
 
0

 
 
 
(474
)
 
Total derivatives
 
$
38,355

 
 
 
$
417

 
 
 
$
(387
)
 
 
$
25,751

 
 
 
$
331

 
 
 
$
(474
)
 
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location The following table presents the gains and losses on derivatives and the related hedged items in fair value hedges for the years ended December 31.

Fair Value Hedging Relationships
(In millions)
 
 
Hedging Derivatives
 
Hedged Items
 
 
Hedging Derivatives
Hedged Items
 
Total
Gains
(Losses)
 
Gains (Losses)
Excluded from Effectiveness Testing(2)
 
Gains (Losses)
Included in Effectiveness Testing(1)
 
 Gains (Losses) (1)
 
Net Realized Gains (Losses) Recognized for Fair Value Hedge
2018:
 
 
 
 
 
 
 
 
 
 
Foreign currency
forwards
Fixed maturity securities
 
$
126

 
$
(104
)
 
$
230

 
$
(242
)
 
$
(12
)
Foreign currency
options
Fixed maturity securities
 
4

 
4

 
0

 
0

 
0

Interest rate
swaptions
Fixed maturity securities
 
(1
)
 
(1
)
 
0

 
0

 
0

   Total gains (losses)
 
$
129

 
$
(101
)
 
$
230

 
$
(242
)
 
$
(12
)
2017:
 
 
 
 
 
 
 
Foreign currency forwards
Fixed maturity and equity securities
 
$
98

 
$
(202
)
 
$
300

 
$
(278
)
 
$
22

Foreign currency options
Fixed maturity securities
 
21

 
10

 
11

 
(10
)
 
1

    Total gains (losses)
 
$
119

 
$
(192
)
 
$
311

 
$
(288
)
 
$
23

2016:
 
 
 
 
 
 
 
Foreign currency forwards
Fixed maturity and equity securities
 
$
207

 
$
(338
)
 
$
545

 
$
(566
)
 
$
(21
)
Foreign currency options
Fixed maturity securities
 
(95
)
 
(18
)
 
(77
)
 
70

 
(7
)
    Total gains (losses)
 
$
112

 
$
(356
)
 
$
468

 
$
(496
)
 
$
(28
)

(1) Gains and losses on foreign currency forwards and options and related hedged items are reported in the consolidated statement of earnings as realized investment gains (losses). For interest rate swaptions and related hedged items, gains and losses included in the hedge assessment are reported within net investment income. For the year ended December 31, 2018, those gains and losses on interest rate swaptions and related hedged items were immaterial.
(2) Gains (losses) excluded from effectiveness testing includes the forward point on foreign currency forwards and time value change on foreign currency options which are reported in the consolidated statement of earnings as realized investment gains (losses). It also includes the change in the fair value of the interest rate swaptions related to the time value of the swaptions which is recognized as a component of other comprehensive income (loss).
Schedule of Interest Rate Fair Value Hedges Hedged Items The following table shows the December 31, 2018 carrying amounts of assets designated and qualifying as hedged items in fair value hedges of interest rate risk and the related cumulative hedge adjustment included in the carrying amount.
(In millions)
Carrying Amount of the Hedged Assets/(Liabilities)(1)
 
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Assets/(Liabilities)
 
 
2018
 
 
 
2018
 
Fixed maturity securities
 
$
6,593

 
 
 
$
294

 
(1) The balance includes $294 million of hedging adjustment on discontinued hedging relationships.
As of December 31, 2018, the total notional amount of the Company's interest rate swaptions was $500 million. The hedging adjustment related to these derivatives was immaterial.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance The following table summarizes the impact to realized investment gains (losses) and other comprehensive income (loss) from all derivatives and hedging instruments for the years ended December 31.
 
2018
2017
2016
(In millions)
Realized Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Realized Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Realized
Investment
Gains (Losses)
Other
Comprehensive
Income (Loss)(1)
Qualifying hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Cash flow hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
$
0

 
 
$
3

 
 
$
0

 
 
$
1

 
 
$
1

 
 
$
3

 
  Total cash flow hedges
 
0

(2) 
 
3

 
 
0

(2) 
 
1

 
 
1

(2) 
 
3

 
  Fair value hedges:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency forwards (3)
 
(116
)
 
 
 
 
 
(180
)
 
 
 
 
 
(359
)
 
 
 
 
       Foreign currency options (3)
 
4

 
 
 
 
 
11

 
 
 
 
 
(25
)
 
 
 
 
       Interest rate swaptions (3)
 
0

 
 
(1
)
 
 
0

 
 
0

 
 
0

 
 
0

 
  Total fair value hedges
 
(112
)
 
 
(1
)
 
 
(169
)
 
 
0

 
 
(384
)
 
 
0

 
  Net investment hedge:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Non-derivative hedging
instruments
 
0

 
 
(32
)
 
 
0

 
 
(15
)
 
 
0

 
 
0

 
       Foreign currency forwards
 
0

 
 
0

 
 
0

 
 
(25
)
 
 
0

 
 
(118
)
 
       Foreign currency options
 
0

 
 
(8
)
 
 
0

 
 
5

 
 
0

 
 
73

 
   Total net investment hedge
 
0

 
 
(40
)
 
 
0

 
 
(35
)
 
 
0

 
 
(45
)
 
  Non-qualifying strategies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
20

 
 
 
 
 
53

 
 
 
 
 
117

 
 
 
 
       Foreign currency forwards
 
(135
)
 
 
 
 
 
8

 
 
 
 
 
9

 
 
 
 
       Credit default swaps
 
0

 
 
 
 
 
(1
)
 
 
 
 
 
2

 
 
 
 
       Interest rate swaps
 
3

 
 
 
 
 
0

 
 
 
 
 
0

 
 
 
 
  Total non- qualifying strategies
 
(112
)
 
 
 
 
 
60

 
 
 
 
 
128

 
 
 
 
          Total
 
$
(224
)
 
 
$
(38
)
 
 
$
(109
)
 
 
$
(34
)
 
 
$
(255
)
 
 
$
(42
)
 
(1) Cash flow hedge items and the change in the fair value of interest rate swaptions related to the time value of the swaptions in fair value hedges are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss).
(2) Impact of cash flow hedges reported as realized investment gains (losses) includes an immaterial amount of gains or losses reclassified from accumulated other comprehensive income (loss) into earnings. It also includes an immaterial amount excluded from effectiveness testing during the years ended December 31, 2018 and 2017 and $1 million during the year ended December 31, 2016.
(3)Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail)
Fair Value and Notional Amount of Derivatives with Counterparty Credit Risk The counterparties to these derivatives are financial institutions with the following credit ratings as of December 31:
 
2018
2017
(In millions)
Notional Amount
of Derivatives
Asset Derivatives
Fair Value
Liability Derivatives
Fair Value
Notional Amount
of Derivatives
Asset Derivatives
Fair Value
Liability Derivatives
Fair Value
Counterparties' credit rating:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
AA
 
$
5,399

 
 
$
63

 
 
$
(23
)
 
 
$
4,708

 
 
$
52

 
 
$
(37
)
 
A
 
32,513

 
 
350

 
 
(311
)
 
 
20,604

 
 
271

 
 
(370
)
 
BBB
 
443

 
 
4

 
 
(53
)
 
 
439

 
 
8

 
 
(67
)
 
Total
 
$
38,355

 
 
$
417

 
 
$
(387
)
 
 
$
25,751

 
 
$
331

 
 
$
(474
)
 
Offsetting Assets Offsetting of Financial Assets and Derivative Assets
2018
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Assets
 
Gross Amount
Offset in
Balance Sheet
 
Net Amount of Assets Presented
 in Balance Sheet
 
Financial Instruments
 
Securities
Collateral
 
Cash Collateral Received
 
Net Amount
Derivative
  assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      assets subject to a
      master netting
      agreement or
      offsetting
      arrangement
 

 
 
 

 
 
 

 
 
 

 
 


 
 

 
 
 

 
          OTC - bilateral
 
$
231

 
 
 
$
0

 
 
 
$
231

 
 
 
$
(152
)
 
 
$
(23
)
 
 
$
(55
)
 
 
 
$
1

 
          OTC - cleared
 
3

 
 
 
0

 
 
 
3

 
 
 
0

 
 
0

 
 
(3
)
 
 
 
0

 
    Total derivative
assets subject to a
master netting
agreement or
offsetting
arrangement
 
234

 
 
 
0

 
 
 
234

 
 
 
(152
)
 
 
(23
)
 
 
(58
)
 
 
 
1

 
    Derivative
      assets not subject
      to a master netting
      agreement or
      offsetting
      arrangement
 

 
 
 

 
 
 

 
 
 

 
 


 
 

 
 
 

 
          OTC - bilateral
 
183

 
 
 
 
 
 
 
183

 
 
 
 
 
 
 
 
 
 
 
 
 
183

 
    Total derivative
assets not subject
to a master netting
agreement or
offsetting
arrangement
 
183

 
 
 
 
 
 
 
183

 
 
 
 
 
 
 
 
 
 
 
 
 
183

 
    Total derivative
      assets
 
417

 
 
 
0

 
 
 
417

 
 
 
(152
)
 
 
(23
)
 
 
(58
)
 
 
 
184

 
Securities lending
   and similar
   arrangements
 
1,029

 
 
 
0

 
 
 
1,029

 
 
 
0

 
 
0

 
 
(1,029
)
 
 
 
0

 
    Total
 
$
1,446

 
 
 
$
0

 
 
 
$
1,446

 
 
 
$
(152
)
 
 
$
(23
)
 
 
$
(1,087
)
 
 
 
$
184

 


2017
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Assets
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Assets Presented in Balance Sheet
 
Financial
Instruments
Securities Collateral
Cash Collateral Received
 
Net Amount
Derivative
  assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      assets subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
$
180

 
 
 
$
0

 
 
 
$
180

 
 
 
$
(82
)
 
 
$
0

 
 
$
(98
)
 
 
 
$
0

 
    Total derivative
assets subject to a
master netting
agreement or
offsetting
arrangement
 
180

 
 
 
0

 
 
 
180

 
 
 
(82
)
 
 
0

 
 
(98
)
 
 
 
0

 
    Derivative
      assets not subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
151

 
 
 
 
 
 
 
151

 
 
 
 
 
 
 
 
 
 
 
 
 
151

 
    Total derivative
assets not subject
to a master netting
agreement or
offsetting
arrangement
 
151

 
 
 
 
 
 
 
151

 
 
 
 
 
 
 
 
 
 
 
 
 
151

 
    Total derivative
      assets
 
331

 
 
 
0

 
 
 
331

 
 
 
(82
)
 
 
0

 
 
(98
)
 
 
 
151

 
Securities lending
   and similar
   arrangements
 
592

 
 
 
0

 
 
 
592

 
 
 
0

 
 
0

 
 
(592
)
 
 
 
0

 
    Total
 
$
923

 
 
 
$
0

 
 
 
$
923

 
 
 
$
(82
)
 
 
$
0

 
 
$
(690
)
 
 
 
$
151

 
Offsetting Liabilities Offsetting of Financial Liabilities and Derivative Liabilities
2018
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Liabilities
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Liabilities Presented in Balance Sheet
 
Financial Instruments
 
Securities Collateral
 
Cash Collateral Pledged
 
Net Amount
Derivative
  liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      liabilities subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 


 
          OTC - bilateral
 
$
(285
)
 
 
 
$
0

 
 
 
$
(285
)
 
 
 
$
152

 
 
$
37

 
 
$
68

 
 
 
$
(28
)
 
    Total derivative
liabilities subject
to a master netting
agreement or
offsetting
arrangement
 
(285
)
 
 
 
0

 
 
 
(285
)
 
 
 
152

 
 
37

 
 
68

 
 
 
(28
)
 
    Derivative
      liabilities not
      subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 
 
 
 
 
 
 
 
 
 
 


 
          OTC - bilateral
 
(102
)
 
 
 
 
 
 
 
(102
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(102
)
 
    Total derivative
liabilities not
subject to a
master netting
agreement or
offsetting
arrangement
 
(102
)
 
 
 
 
 
 
 
(102
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(102
)
 
    Total derivative
      liabilities
 
(387
)
 
 
 
0

 
 
 
(387
)
 
 
 
152

 
 
37

 
 
68

 
 
 
(130
)
 
Securities lending
   and similar
   arrangements
 
(1,052
)
 
 
 
0

 
 
 
(1,052
)
 
 
 
1,029

 
 
0

 
 
0

 
 
 
(23
)
 
    Total
 
$
(1,439
)
 
 
 
$
0

 
 
 
$
(1,439
)
 
 
 
$
1,181

 
 
$
37

 
 
$
68

 
 
 
$
(153
)
 


2017
 
 
 
Gross Amounts Not Offset
in Balance Sheet
 
 
(In millions)
Gross Amount of Recognized Liabilities
 
Gross Amount Offset in Balance Sheet
 
Net Amount of Liabilities Presented in Balance Sheet
 
Financial Instruments
 
Securities Collateral
 
Cash Collateral Pledged
 
Net Amount
Derivative
  liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
    Derivative
      liabilities subject
      to a master netting
      agreement or
      offsetting
      arrangement
 


 
 
 


 
 
 


 
 
 


 
 


 
 


 
 
 

 
          OTC - bilateral
 
$
(346
)
 
 
 
$
0

 
 
 
$
(346
)
 
 
 
$
82

 
 
$
245

 
 
$
10

 
 
 
$
(9
)
 
    Total derivative
liabilities subject
to a master netting
agreement or
offsetting
arrangement
 
(346
)
 
 
 
0

 
 
 
(346
)
 
 
 
82

 
 
245

 
 
10

 
 
 
(9
)
 
    Derivative
      liabilities not
      subject to a
      master netting
      agreement or
      offsetting
      arrangement
 


 
 
 
 
 
 
 


 
 
 
 
 
 
 
 
 
 
 
 
 

 
          OTC - bilateral
 
(128
)
 
 
 
 
 
 
 
(128
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(128
)
 
    Total derivative
liabilities not
subject to a
master netting
agreement or
offsetting
arrangement
 
(128
)
 
 
 
 
 
 
 
(128
)
 
 
 
 
 
 
 
 
 
 
 
 
 
(128
)
 
    Total derivative
      liabilities
 
(474
)
 
 
 
0

 
 
 
(474
)
 
 
 
82

 
 
245

 
 
10

 
 
 
(137
)
 
Securities lending
   and similar
   arrangements
 
(606
)
 
 
 
0

 
 
 
(606
)
 
 
 
592

 
 
0

 
 
0

 
 
 
(14
)
 
    Total
 
$
(1,080
)
 
 
 
$
0

 
 
 
$
(1,080
)
 
 
 
$
674

 
 
$
245

 
 
$
10

 
 
 
$
(151
)
 
v3.10.0.1
FAIR VALUE MEASUREMENTS (Tables)
 12 Months Ended
Dec. 31, 2018
Fair Value Disclosures [Abstract]  
Fair Value Hierarchy, Assets and Liabilities Measured on Recurring Basis The following tables present the fair value hierarchy levels of the Company's assets and liabilities that are measured and carried at fair value on a recurring basis as of December 31.
  
2018
(In millions)
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities available for sale, carried at
fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
32,993

 
 
 
$
1,349

 
 
 
$
0

 
 
 
$
34,342

 
Municipalities
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
Mortgage- and asset-backed securities
 
0

 
 
 
162

 
 
 
177

 
 
 
339

 
Public utilities
 
0

 
 
 
7,062

 
 
 
109

 
 
 
7,171

 
Sovereign and supranational
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
Banks/financial institutions
 
0

 
 
 
8,895

 
 
 
23

 
 
 
8,918

 
Other corporate
 
0

 
 
 
28,789

 
 
 
213

 
 
 
29,002

 
Total fixed maturity securities
 
32,993

 
 
 
49,380

 
 
 
522

 
 
 
82,895

(1) 
Equity securities (1)
 
874

 
 
 
67

 
 
 
46

 
 
 
987

(1) 
Other investments
 
152

 
 
 
0

 
 
 
0

 
 
 
152

 
Cash and cash equivalents
 
4,337

 
 
 
0

 
 
 
0

 
 
 
4,337

 
Other assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
0

 
 
 
103

 
 
 
182

 
 
 
285

 
Foreign currency forwards
 
0

 
 
 
126

 
 
 
0

 
 
 
126

 
Foreign currency options
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Interest rate swaps
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Total other assets
 
0

 
 
 
235

 
 
 
182

 
 
 
417

 
Total assets
 
$
38,356

 
 
 
$
49,682

 
 
 
$
750

 
 
 
$
88,788

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
0

 
 
 
$
132

 
 
 
$
102

 
 
 
$
234

 
Foreign currency forwards
 
0

 
 
 
151

 
 
 
0

 
 
 
151

 
Foreign currency options
 
0

 
 
 
1

 
 
 
0

 
 
 
1

 
Interest rate swaptions
 
0

 
 
 
1

 
 
 
0

 
 
 
1

 
Total liabilities
 
$
0

 
 
 
$
285

 
 
 
$
102

 
 
 
$
387

 

(1) Includes perpetual securities

  
2017
(In millions)
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities available for sale, carried at
fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
30,109

 
 
 
$
1,121

 
 
 
$
0

 
 
 
$
31,230

 
Municipalities
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
Mortgage- and asset-backed securities
 
0

 
 
 
269

 
 
 
175

 
 
 
444

 
Public utilities
 
0

 
 
 
7,886

 
 
 
68

 
 
 
7,954

 
Sovereign and supranational
 
0

 
 
 
1,909

 
 
 
0

 
 
 
1,909

 
Banks/financial institutions
 
0

 
 
 
8,908

 
 
 
25

 
 
 
8,933

 
Other corporate
 
0

 
 
 
32,327

 
 
 
146

 
 
 
32,473

 
Total fixed maturity securities
 
30,109

 
 
 
53,790

 
 
 
414

 
 
 
84,313

(1) 
Equity securities
 
1,001

 
 
 
6

 
 
 
16

 
 
 
1,023

 
Other investments
 
57

 
 
 
0

 
 
 
0

 
 
 
57

 
Cash and cash equivalents
 
3,491

 
 
 
0

 
 
 
0

 
 
 
3,491

 
Other assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
0

 
 
 
146

 
 
 
150

 
 
 
296

 
Foreign currency forwards
 
0

 
 
 
22

 
 
 
0

 
 
 
22

 
Foreign currency options
 
0

 
 
 
12

 
 
 
0

 
 
 
12

 
Credit default swaps
 
0

 
 
 
0

 
 
 
1

 
 
 
1

 
Total other assets
 
0

 
 
 
180

 
 
 
151

 
 
 
331

 
Total assets
 
$
34,658

 
 
 
$
53,976

 
 
 
$
581

 
 
 
$
89,215

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Foreign currency swaps
 
$
0

 
 
 
$
69

 
 
 
$
128

 
 
 
$
197

 
Foreign currency forwards
 
0

 
 
 
274

 
 
 
0

 
 
 
274

 
Foreign currency options
 
0

 
 
 
3

 
 
 
0

 
 
 
3

 
Total liabilities
 
$
0

 
 
 
$
346

 
 
 
$
128

 
 
 
$
474

 

(1) Includes perpetual securities
Fair Value Hierarchy Levels of Assets and Liabilities Carried at Cost or Amortized Cost The following tables present the carrying amount and fair value categorized by fair value hierarchy level for the Company's financial instruments that are not carried at fair value as of December 31.
 
2018
(In millions)
Carrying
Value
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
Total
Fair
Value
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities held to maturity,
carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
21,712

 
 
$
27,030

 
 
 
$
8

 
 
 
$
0

 
 
 
$
27,038

 
Municipalities
 
359

 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
Mortgage and asset-backed
securities
 
14

 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
Public utilities
 
2,727

 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
Sovereign and
supranational
 
1,551

 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
Banks/financial institutions
 
1,445

 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
Other corporate
 
2,510

 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
Other investments (1)
 
6,945

 
 
0

 
 
 
26

 
 
 
6,893

 
 
 
6,919

 
 Total assets
 
$
37,263

 
 
$
27,030

 
 
 
$
9,703

 
 
 
$
6,908

 
 
 
$
43,641

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other policyholders’ funds
 
$
7,146

 
 
$
0

 
 
 
$
0

 
 
 
$
7,067

 
 
 
$
7,067

 
Notes payable
(excluding capital leases)
 
5,765

 
 
0

 
 
 
5,606

 
 
 
270

 
 
 
5,876

 
Total liabilities
 
$
12,911

 
 
$
0

 
 
 
$
5,606

 
 
 
$
7,337

 
 
 
$
12,943

 
(1) Excludes policy loans of $232 and equity method investments of $377, at carrying value

 
 
 
 
2017
(In millions)
Carrying
Value
Quoted Prices in
Active Markets
for Identical
Assets
(Level 1)
 
Significant
Observable
Inputs
(Level 2)
 
Significant
Unobservable
Inputs
(Level 3)
 
Total
Fair
Value
Assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Securities held to maturity,
carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Government and agencies
 
$
21,331

 
 
$
26,491

 
 
 
$
0

 
 
 
$
0

 
 
 
$
26,491

 
Municipalities
 
357

 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
Mortgage and asset-backed
securities
 
26

 
 
0

 
 
 
8

 
 
 
19

 
 
 
27

 
Public utilities
 
3,300

 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
Sovereign and
supranational
 
1,523

 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
Banks/financial institutions
 
2,206

 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
Other corporate
 
2,687

 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
Other investments (1)
 
3,017

 
 
0

 
 
 
15

 
 
 
2,987

 
 
 
3,002

 
  Total assets
 
$
34,447

 
 
$
26,491

 
 
 
$
11,577

 
 
 
$
3,006

 
 
 
$
41,074

 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Other policyholders’ funds
 
$
6,939

 
 
$
0

 
 
 
$
0

 
 
 
$
6,841

 
 
 
$
6,841

 
Notes payable
(excluding capital leases)
 
5,267

 
 
0

 
 
 
5,288

 
 
 
265

 
 
 
5,553

 
Total liabilities
 
$
12,206

 
 
$
0

 
 
 
$
5,288

 
 
 
$
7,106

 
 
 
$
12,394

 

(1) Excludes policy loans of $210 and equity method investments of $118, at carrying value
Fair Value Assets Securities Carried At Fair Value Primary Pricing Sources The following tables present the pricing sources for the fair values of the Company's fixed maturity and equity securities as of December 31.
 
 
2018
(In millions)
 
Quoted Prices in Active Markets for Identical Assets
(Level 1)
 
Significant Observable Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
32,993

 
 
 
$
1,349

 
 
 
$
0

 
 
 
$
34,342

 
               Total government and agencies
 
 
32,993

 
 
 
1,349

 
 
 
0

 
 
 
34,342

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
               Total municipalities
 
 
0

 
 
 
1,863

 
 
 
0

 
 
 
1,863

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
162

 
 
 
0

 
 
 
162

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
177

 
 
 
177

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
162

 
 
 
177

 
 
 
339

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
7,062

 
 
 
0

 
 
 
7,062

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
109

 
 
 
109

 
               Total public utilities
 
 
0

 
 
 
7,062

 
 
 
109

 
 
 
7,171

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
               Total sovereign and supranational
 
 
0

 
 
 
1,260

 
 
 
0

 
 
 
1,260

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8,895

 
 
 
0

 
 
 
8,895

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
23

 
 
 
23

 
               Total banks/financial institutions
 
 
0

 
 
 
8,895

 
 
 
23

 
 
 
8,918

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
28,789

 
 
 
0

 
 
 
28,789

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
213

 
 
 
213

 
               Total other corporate
 
 
0

 
 
 
28,789

 
 
 
213

 
 
 
29,002

 
                  Total securities available for sale
 
 
$
32,993

 
 
 
$
49,380

 
 
 
$
522

 
 
 
$
82,895

(1) 
Equity securities, carried at fair value: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
874

 
 
 
$
67

 
 
 
$
0

 
 
 
$
941

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
46

 
 
 
46

 
               Total equity securities
 
 
$
874

 
 
 
$
67

 
 
 
$
46

 
 
 
$
987

(1) 

(1) Includes perpetual securities
 
 
2017
(In millions)
 
Quoted Prices in Active Markets
for Identical Assets
(Level 1)
 
Significant Observable
Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities: (1)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
30,109

 
 
 
$
1,121

 
 
 
$
0

 
 
 
$
31,230

 
               Total government and agencies
 
 
30,109

 
 
 
1,121

 
 
 
0

 
 
 
31,230

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
               Total municipalities
 
 
0

 
 
 
1,370

 
 
 
0

 
 
 
1,370

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
269

 
 
 
0

 
 
 
269

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
175

 
 
 
175

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
269

 
 
 
175

 
 
 
444

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
7,886

 
 
 
0

 
 
 
7,886

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
68

 
 
 
68

 
               Total public utilities
 
 
0

 
 
 
7,886

 
 
 
68

 
 
 
7,954

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,807

 
 
 
0

 
 
 
1,807

 
            Broker/other
 
 
0

 
 
 
102

 
 
 
0

 
 
 
102

 
               Total sovereign and supranational
 
 
0

 
 
 
1,909

 
 
 
0

 
 
 
1,909

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8,908

 
 
 
0

 
 
 
8,908

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
25

 
 
 
25

 
               Total banks/financial institutions
 
 
0

 
 
 
8,908

 
 
 
25

 
 
 
8,933

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
32,327

 
 
 
0

 
 
 
32,327

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
146

 
 
 
146

 
               Total other corporate
 
 
0

 
 
 
32,327

 
 
 
146

 
 
 
32,473

 
                  Total securities available for sale
 
 
$
30,109

 
 
 
$
53,790

 
 
 
$
414

 
 
 
$
84,313

(1) 
Equity securities, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
1,001

 
 
 
$
6

 
 
 
$
0

 
 
 
$
1,007

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
16

 
 
 
16

 
               Total equity securities
 
 
$
1,001

 
 
 
$
6

 
 
 
$
16

 
 
 
$
1,023

 

(1) Includes perpetual securities

Fair Value Assets Held-To-Maturity Securities Primary Pricing Sources
 
 
2018
(In millions)
 
Quoted Prices in Active Markets for Identical Assets
(Level 1)
 
Significant Observable Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
27,030

 
 
 
$
8

 
 
 
$
0

 
 
 
$
27,038

 
               Total government and agencies
 
 
27,030

 
 
 
8

 
 
 
0

 
 
 
27,038

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
               Total municipalities
 
 
0

 
 
 
469

 
 
 
0

 
 
 
469

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Broker/other
 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
0

 
 
 
15

 
 
 
15

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
               Total public utilities
 
 
0

 
 
 
2,973

 
 
 
0

 
 
 
2,973

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
               Total sovereign and supranational
 
 
0

 
 
 
1,840

 
 
 
0

 
 
 
1,840

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
               Total banks/financial institutions
 
 
0

 
 
 
1,583

 
 
 
0

 
 
 
1,583

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
               Total other corporate
 
 
0

 
 
 
2,804

 
 
 
0

 
 
 
2,804

 
                  Total securities held to maturity
 
 
$
27,030

 
 
 
$
9,677

 
 
 
$
15

 
 
 
$
36,722

 
 
 
2017
(In millions)
 
Quoted Prices in Active Markets
for Identical Assets
(Level 1)
 
Significant Observable
Inputs
(Level 2)
 
Significant Unobservable Inputs
(Level 3)
 
Total
Fair
Value
Securities held to maturity, carried at amortized cost:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
         Government and agencies:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
$
26,491

 
 
 
$
0

 
 
 
$
0

 
 
 
$
26,491

 
               Total government and agencies
 
 
26,491

 
 
 
0

 
 
 
0

 
 
 
26,491

 
         Municipalities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
               Total municipalities
 
 
0

 
 
 
462

 
 
 
0

 
 
 
462

 
         Mortgage- and asset-backed securities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
8

 
 
 
0

 
 
 
8

 
            Broker/other
 
 
0

 
 
 
0

 
 
 
19

 
 
 
19

 
               Total mortgage- and asset-backed securities
 
 
0

 
 
 
8

 
 
 
19

 
 
 
27

 
         Public utilities:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
               Total public utilities
 
 
0

 
 
 
3,698

 
 
 
0

 
 
 
3,698

 
         Sovereign and supranational:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
               Total sovereign and supranational
 
 
0

 
 
 
1,835

 
 
 
0

 
 
 
1,835

 
         Banks/financial institutions:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
               Total banks/financial institutions
 
 
0

 
 
 
2,387

 
 
 
0

 
 
 
2,387

 
         Other corporate:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
            Third party pricing vendor
 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
               Total other corporate
 
 
0

 
 
 
3,172

 
 
 
0

 
 
 
3,172

 
                  Total securities held to maturity
 
 
$
26,491

 
 
 
$
11,562

 
 
 
$
19

 
 
 
$
38,072

 
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation The following tables present the changes in fair value of the Company's investments and derivatives carried at fair value classified as Level 3 as of December 31.
2018
 
 
Fixed Maturity Securities
 
Equity
Securities
 
Derivatives(1)
 
 
 
(In millions)
Mortgage-
and
Asset-
Backed
Securities
 
Public
Utilities
 
Banks/
Financial
Institutions
 
Other
Corporate
 
 
 
Foreign
Currency
Swaps
 
Credit
Default
Swaps
 
Total
 
Balance, beginning of period
$
175

 
$
68

 
$
25

 
$
146

 
$
16

 
$
22

 
$
1

 
$
453

 
Realized investment gains (losses) included
in earnings
0

 
0

 
0

 
0

 
(1
)
 
54

 
(1
)
 
52

 
Unrealized gains (losses) included in other
comprehensive income (loss)
2

 
1

 
(2
)
 
1

 
0

 
4

 
0

 
6

 
Purchases, issuances, sales and settlements:
 
 
 
 
 
 
 
 
 
 

 

 

 
Purchases
0

 
40

 
0

 
56

 
31

 
0

 
0

 
127

 
Issuances
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Sales
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Settlements
0

 
0

 
0

 
(6
)
 
0

 
0

 
0

 
(6
)
 
Transfers into Level 3
0

 
0

 
0

 
16

 
0

 
0

 
0

 
16

 
Transfers out of Level 3
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Balance, end of period
$
177

 
$
109

 
$
23

 
$
213

 
$
46

 
$
80

 
$
0

 
$
648

 
Changes in unrealized gains (losses) relating
to Level 3 assets and liabilities still held at
the end of the period included in realized
investment gains (losses)
$
0

 
$
0

 
$
0

 
$
0

 
$
(1
)
 
$
54

 
$
(1
)
 
$
52

 

(1) Derivative assets and liabilities are presented net


2017
 
  
Fixed Maturity Securities
 
 
 
Equity
Securities
 
Derivatives(1)
 
  
 
(In millions)
Mortgage-
and
Asset-
Backed
Securities
 
Public
Utilities
 
Banks/
Financial
Institutions
 
Other
Corporate
 
 
 
Foreign
Currency
Swaps
 
Credit
Default
Swaps
 
Total
 
Balance, beginning of period
$
198

 
$
16

 
$
25

 
$
0

 
$
3

 
$
(21
)
 
$
2

 
$
223

 
Realized investment gains (losses) included in
earnings
0

 
0

 
0

 
0

 
0

 
43

 
(1
)
 
42

 
Unrealized gains (losses) included in other
comprehensive income (loss)
3

 
0

 
0

 
2

 
0

 
0

 
0

 
5

 
Purchases, issuances, sales and settlements:


 
 
 


 
 
 


 


 


 


 
Purchases
0

 
76

 
0

 
122

 
16

 
0

 
0

 
214

 
Issuances
0

 
0

 
0

 
0

 
0

 
0

 
0

 
0

 
Sales
0

 
0

 
0

 
(2
)
 
(1
)
 
0

 
0

 
(3
)
 
Settlements
(26
)
 
0

 
0

 
0

 
0

 
0

 
0

 
(26
)
 
Transfers into Level 3
0

 
0

 
0

 
24

(2) 
0

 
0

 
0

 
24

 
Transfers out of Level 3
0

 
(24
)
(2) 
0

 
0

 
(2
)
(3) 
0

 
0

 
(26
)
 
Balance, end of period
$
175

 
$
68

 
$
25

 
$
146

 
$
16

 
$
22

 
$
1

 
$
453

 
Changes in unrealized gains (losses) relating
to Level 3 assets and liabilities still held at
the end of the period included in realized
investment gains (losses)
$
0

 
$
0

 
$
0

 
$
0

 
$
0

 
$
43

 
$
(1
)
 
$
42

 

(1) Derivative assets and liabilities are presented net
(2) Transfer due to sector classification change
(3) Transfer due to change in accounting method
Fair Value Measurement Inputs and Valuation Techniques Level 3 Significant Unobservable Input Sensitivity

The following tables summarize the significant unobservable inputs used in the valuation of the Company's Level 3 investments and derivatives carried at fair value as of December 31. Included in the tables are the inputs or range of possible inputs that have an effect on the overall valuation of the financial instruments.
2018
(In millions)
 
Fair Value
 
Valuation Technique(s)
 
Unobservable Input
 
Range
(Weighted Average)
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
  Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
    Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
       Mortgage- and asset-backed securities
 
 
$
177

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Public utilities
 
 
109

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
       Banks/financial institutions
 
 
23

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Other corporate
 
 
213

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
  Equity securities
 
 
46

 
 
Net asset value
 
Offered quotes
 
N/A
(a) 
  Other assets:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
125

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
19 - 120 bps
 
 
 
 
57

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
            Total assets
 
 
$
750

 
 
 
 
 
 
 
 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
  Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
$
98

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
28 - 211 bps
 
 
 
 
4

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.75% - 2.84%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.18% - .71%
(c) 
            Total liabilities
 
 
$
102

 
 
 
 
 
 
 
 

(a) N/A represents securities where the Company receives unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs.
(b) Inputs derived from U.S. long-term rates to accommodate long maturity nature of the Company's swaps
(c) Inputs derived from Japan long-term rates to accommodate long maturity nature of the Company's swaps





2017
(In millions)
 
Fair Value
 
Valuation Technique(s)
 
Unobservable Input
 
Range
(Weighted Average)
 
Assets:
 
 
 
 
 
 
 
 
 
 
 
  Securities available for sale, carried at fair value:
 
 
 
 
 
 
 
 
 
 
 
    Fixed maturity securities:
 
 
 
 
 
 
 
 
 
 
 
       Mortgage- and asset-backed securities
 
 
$
175

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Public utilities
 
 
68

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
       Banks/financial institutions
 
 
25

 
 
Consensus pricing
 
Offered quotes
 
N/A
(a) 
       Other corporate
 
 
146

 
 
Discounted cash flow
 
Credit spreads
 
N/A
(a) 
  Equity securities
 
 
16

 
 
Net asset value
 
Offered quotes
 
N/A
(a) 
  Other assets:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
80

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
9 - 90 bps
 
 
 
 
70

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
       Credit default swaps
 
 
1

 
 
Discounted cash flow
 
Base correlation
 
    46.33% - 49.65%
(d) 
 
 
 
 
 
 
 
 
CDS spreads
 
25 bps
 
 
 
 
 
 
 
 
 
Recovery rate
 
37.24%
 
            Total assets
 
 
$
581

 
 
 
 
 
 
 
 
Liabilities:
 
 
 
 
 
 
 
 
 
 
 
  Other liabilities:
 
 
 
 
 
 
 
 
 
 
 
       Foreign currency swaps
 
 
$
120

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
 
 
 
 
 
 
 
 
CDS spreads
 
13 - 157 bps
 
 
 
 
8

 
 
Discounted cash flow
 
Interest rates (USD)
 
2.40% - 2.54%
(b) 
 
 
 
 
 
 
 
 
Interest rates (JPY)
 
.26% - .85%
(c) 
            Total liabilities
 
 
$
128

 
 
 
 
 
 
 
 

(a) N/A represents securities where the Company receives unadjusted broker quotes and for which there is no transparency into the providers' valuation techniques or unobservable inputs.
(b) Inputs derived from U.S. long-term rates to accommodate long maturity nature of the Company's swaps
(c) Inputs derived from Japan long-term rates to accommodate long maturity nature of the Company's swaps
(d) Range of base correlation for the Company's bespoke tranche for attachment and detachment points corresponding to market indices
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES (Tables)
 12 Months Ended
Dec. 31, 2018
Deferred Policy Acquisition Costs Disclosures [Abstract]  
Schedule of Deferred Policy Acquisition Costs The following table presents a rollforward of deferred policy acquisition costs by segment for the years ended December 31.
  
2018
 
2017
(In millions)
Japan
 
U.S.
 
Japan
 
U.S.
Deferred policy acquisition costs:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Balance, beginning of year
 
$
6,150

 
 
 
$
3,355

 
 
 
$
5,765

 
 
 
$
3,228

 
Capitalization
 
833

 
 
 
669

 
 
 
839

 
 
 
629

 
Amortization
 
(710
)
 
 
 
(534
)
 
 
 
(630
)
 
 
 
(502
)
 
Foreign currency translation and other
 
111

 
 
 
1

 
 
 
176

 
 
 
0

 
Balance, end of year
 
$
6,384

 
 
 
$
3,491

 
 
 
$
6,150

 
 
 
$
3,355

 
Advertising Expense Advertising expense, which is included in insurance expenses in the consolidated statements of earnings, was as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Advertising expense:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
108

 
 
 
$
100

 
 
 
$
100

 
Aflac U.S.
 
110

 
 
 
110

 
 
 
124

 
          Total advertising expense
 
$
218

 
 
 
$
210

 
 
 
$
224

 
Schedule Of Depreciation And Amortization Expense Depreciation and other amortization expenses, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Depreciation expense
 
$
48

 
 
 
$
50

 
 
 
$
48

 
Other amortization expense
 
1

 
 
 
3

 
 
 
6

 
          Total depreciation and other amortization expense
 
$
49

 
 
 
$
53

 
 
 
$
54

 
Schedule of Lease Expenses Lease and rental expense, which are included in insurance expenses in the consolidated statements of earnings, were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Lease and rental expense:
 
 
 
 
 
 
 
 
 
 
 
Aflac Japan
 
$
53

 
 
 
$
52

 
 
 
$
53

 
Aflac U.S.
 
16

 
 
 
21

 
 
 
21

 
Other
 
4

 
 
 
2

 
 
 
1

 
          Total lease and rental expense
 
$
73

 
 
 
$
75

 
 
 
$
75

 
v3.10.0.1
POLICY LIABILITIES (Tables)
 12 Months Ended
Dec. 31, 2018
Insurance Loss Reserves [Abstract]  
Liability for Future Policy Benefits by Product Segment The liability for future policy benefits as of December 31 consisted of the following:
  
  
 
Liability Amounts
 
 
Interest Rates
(In millions)
Policy
Issue Year
 
2018
 
2017
 
 
Year of
Issue
 
In 20
Years
Health insurance:
 
 
 
 
 
 
 
 
 
 
 
 
Japan:
1992 - 2018
 
$
11,598

 
$
10,167

 
 
1.0 - 2.5
%
 
1.0 - 2.5
%
 
1974 - 2013
 
1,161

 
1,133

 
 
2.7 - 2.75
 
 
2.25 - 2.75
 
 
1998 - 2018
 
12,764

 
12,386

 
 
3.0
 
 
3.0
 
 
1997 - 1999
 
2,452

 
2,454

 
 
3.5
 
 
3.5
 
 
1994 - 1996
 
3,056

 
3,046

 
 
4.0 - 4.5
 
 
4.0 - 4.5
 
 
1987 - 1994
 
14,722

 
14,829

 
 
5.5
 
 
5.5
 
 
1985 - 1991
 
1,779

 
1,816

 
 
5.25 - 6.75
 
 
5.25 - 5.5
 
 
1978 - 1984
 
1,964

 
2,037

 
 
6.5
 
 
5.5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S.:
2013 - 2018
 
96

 
82

 
 
3.0 - 3.5
 
 
3.0 - 3.5
 
 
2012 - 2018
 
1,682

 
1,366

 
 
3.75
 
 
3.75
 
 
2011
 
353

 
343

 
 
4.75
 
 
4.75
 
 
2005 - 2010
 
2,946

 
2,944

 
 
5.5
 
 
5.5
 
 
1988 - 2004
 
641

 
656

 
 
8.0
 
 
6.0
 
 
1986 - 2004
 
1,245

 
1,296

 
 
6.0
 
 
6.0
 
 
1981 - 1986
 
151

 
159

 
 
6.5 - 7.0
 
 
5.5 - 6.5
 
 
1998 - 2004
 
1,311

 
1,310

 
 
7.0
 
 
7.0
 
 
Other
 
17

 
18

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Intercompany eliminations:
2015
 
(583
)
(1) 
(609
)
(1) 
 
2.0
 
 
2.0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Life insurance:
 
 
 
 
 
 
 
 
 
 
 
 
Japan:
2001 - 2018
 
10,296

 
8,850

 
 
1.0 - 1.85
 
 
1.0 - 1.85
 
 
2011 - 2017
 
5,116

 
4,763

 
 
2.0
 
 
2.0
 
 
2009 - 2011
 
3,867

 
3,393

 
 
2.25
 
 
2.25
 
 
1992 - 2006
 
5

 
5

 
 
2.19
 
 
1.55
 
 
2005 - 2011
 
1,769

 
1,642

 
 
2.5
 
 
2.5
 
 
1985 - 2006
 
2,057

 
2,048

 
 
2.7
 
 
2.25
 
 
2007 - 2011
 
1,380

 
1,319

 
 
2.75
 
 
2.75
 
 
1999 - 2011
 
2,249

 
2,189

 
 
3.0
 
 
3.0
 
 
1996 - 2009
 
678

 
675

 
 
3.5
 
 
3.5
 
 
1994 - 1996
 
901

 
908

 
 
4.0 - 4.5
 
 
4.0 - 4.5
 
 
 
 
 
 
 
 
 
 
 
 
 
 
U.S.:
1956 - 2018
 
695

 
632

 
 
3.5 - 6.0
 
 
3.5 - 6.0
 
Total
 
 
$
86,368

 
$
81,857

 
 
 
 
 
 
 
(1) Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements
Schedule of Liability for Unpaid Claims Adjustment Expense Changes in the liability for unpaid policy claims were as follows for the years ended December 31:
(In millions)
2018
 
2017
 
2016
Unpaid supplemental health claims, beginning of period
 
$
3,884

 
 
 
$
3,707

 
 
 
$
3,548

 
Less reinsurance recoverables
 
30

 
 
 
27

 
 
 
26

 
Net balance, beginning of period
 
3,854

 
 
 
3,680

 
 
 
3,522

 
Add claims incurred during the period related to:
 
 
 
 
 
 
 
 
 
 
 
Current year
 
7,101

 
 
 
6,979

 
 
 
7,037

 
Prior years
 
(563
)
 
 
 
(518
)
 
 
 
(465
)
 
Total incurred
 
6,538

 
 
 
6,461

 
 
 
6,572

 
Less claims paid during the period on claims incurred during:
 
 
 
 
 
 
 
 
 
 
 
Current year
 
4,612

 
 
 
4,530

 
 
 
4,613

 
Prior years
 
1,898

 
 
 
1,822

 
 
 
1,865

 
Total paid
 
6,510

 
 
 
6,352

 
 
 
6,478

 
Effect of foreign exchange rate changes on unpaid claims
 
43

 
 
 
65

 
 
 
64

 
Net balance, end of period
 
3,925

 
 
 
3,854

 
 
 
3,680

 
Add reinsurance recoverables
 
27

 
 
 
30

 
 
 
27

 
Unpaid supplemental health claims, end of period
 
3,952

 
 
 
3,884

 
 
 
3,707

 
Unpaid life claims, end of period
 
632

 
 
 
508

 
 
 
338

 
Total liability for unpaid policy claims
 
$
4,584

 
 
 
$
4,392

 
 
 
$
4,045

 
v3.10.0.1
REINSURANCE (Tables)
 12 Months Ended
Dec. 31, 2018
Reinsurance Disclosures [Abstract]  
Effects of Reinsurance The following table reconciles direct premium income and direct benefits and claims to net amounts after the effect of reinsurance for the years ended December 31.
(In millions)
2018
2017
2016
Direct premium income
 
$
19,018

 
 
$
18,875

 
 
$
19,592

 
Ceded to other companies:
 
 
 
 
 
 
 
 
 
    Ceded Aflac Japan closed blocks
 
(497
)
 
 
(515
)
 
 
(560
)
 
    Other
 
(58
)
 
 
(51
)
 
 
(48
)
 
Assumed from other companies:
 
 
 
 
 
 
 
 
 
    Retrocession activities
 
208

 
 
216

 
 
234

 
    Other
 
6

 
 
6

 
 
7

 
Net premium income
 
$
18,677

 
 
$
18,531

 
 
$
19,225

 
 
 
 
 
 
 
 
 
 
 
Direct benefits and claims
 
$
12,293

 
 
$
12,486

 
 
$
13,240

 
Ceded benefits and change in reserves for future benefits:
 
 
 
 
 
 
 
 
 
    Ceded Aflac Japan closed blocks
 
(450
)
 
 
(473
)
 
 
(509
)
 
    Eliminations
 
43

 
 
51

 
 
58

 
    Other
 
(44
)
 
 
(44
)
 
 
(38
)
 
Assumed from other companies:
 
 
 
 
 
 
 
 
 
    Retrocession activities
 
209

 
 
209

 
 
222

 
    Eliminations
 
(53
)
 
 
(51
)
 
 
(58
)
 
    Other
 
2

 
 
3

 
 
4

 
Benefits and claims, net
 
$
12,000

 
 
$
12,181

 
 
$
12,919

 
v3.10.0.1
NOTES PAYABLE (Tables)
 12 Months Ended
Dec. 31, 2018
Debt Disclosure [Abstract]  
Schedule of Long-term Debt Instruments A summary of notes payable as of December 31 follows:
(In millions)
2018
 
2017
2.40% senior notes paid November 2018
 
$
0

 
 
 
$
548

 
4.00% senior notes due February 2022
 
348

 
 
 
348

 
3.625% senior notes due June 2023
 
698

 
 
 
697

 
3.625% senior notes due November 2024
 
746

 
 
 
745

 
3.25% senior notes due March 2025
 
447

 
 
 
446

 
2.875% senior notes due October 2026
 
297

 
 
 
297

 
6.90% senior notes due December 2039
 
220

 
 
 
220

 
6.45% senior notes due August 2040
 
254

 
 
 
254

 
4.00% senior notes due October 2046
 
394

 
 
 
394

 
4.750% senior notes due January 2049
 
540

 
 
 
0

 
Yen-denominated senior notes and subordinated debentures:
 
 
 
 
 
 
 
.932% senior notes due January 2027 (principal amount 60.0 billion yen)
 
538

 
 
 
528

 
1.159% senior notes due October 2030 (principal amount 29.3 billion yen)
 
262

 
 
 
0

 
1.488% senior notes due October 2033 (principal amount 15.2 billion yen)
 
136

 
 
 
0

 
1.750% senior notes due October 2038 (principal amount 8.9 billion yen)
 
79

 
 
 
0

 
2.108% subordinated debentures due October 2047 (principal amount 60.0 billion yen)
 
536

 
 
 
526

 
Yen-denominated loans:
 
 
 
 
 
 
 
Variable interest rate loan due September 2021 (.32% in 2018 and 2017, principal amount 5.0 billion yen)
 
45

 
 
 
44

 
Variable interest rate loan due September 2023 (.47% in 2018 and 2017, principal amount 25.0 billion yen)
 
225

 
 
 
220

 
Capitalized lease obligations payable through 2025
 
13

 
 
 
22

 
Total notes payable
 
$
5,778

 
 
 
$
5,289

 

Amounts in the table above are reported net of debt issuance costs and issuance premiums or discounts, if applicable, that are being amortized over the life of the notes.
Schedule of Maturities of Long Term Debt The aggregate contractual maturities of notes payable during each of the years after December 31, 2018, are as follows:
(In millions)
Long-term
Debt
 
Capitalized
Lease
Obligations
 
Total
Notes
Payable
2019
 
$
0

 
 
 
$
5

 
 
 
$
5

 
2020
 
0

 
 
 
3

 
 
 
3

 
2021
 
45

 
 
 
2

 
 
 
47

 
2022
 
350

 
 
 
1

 
 
 
351

 
2023
 
925

 
 
 
1

 
 
 
926

 
Thereafter
 
4,493

 
 
 
1

 
 
 
4,494

 
Total
 
$
5,813

 
 
 
$
13

 
 
 
$
5,826

 
Schedule of Line of Credit Facilities A summary of the Company's lines of credit as of December 31, 2018 follows:
Borrower
Type
Original Term
Expiration Date
Capacity
Amount Outstanding
Interest Rate on Borrowed Amount
Maturity Period
Commitment Fee
Business Purpose
Aflac Incorporated
and Aflac
uncommitted bilateral
364 days
December 27, 2019
$100 million
$0 million
The rate quoted by the bank and agreed upon at the time of borrowing
Up to 3 months
None
General corporate purposes
Aflac Incorporated
unsecured revolving
3 years
March 31, 2019, or the date commitments are terminated pursuant to an event of default
100.0 billion yen
0.0 billion yen
A rate per annum equal to (a) Tokyo interbank market rate (TIBOR) plus, the alternative applicable TIBOR margin during the availability period from the closing date to the commitment termination date or (b) the TIBOR rate offered by the agent to major banks in yen for the applicable period plus, the applicable alternative TIBOR margin during the term out period
No later than
March 31, 2019
.30% to .50%, depending on the Parent Company's debt ratings as of the date of determination
General corporate purposes, including a capital contingency plan for the operations of the Parent Company
Aflac Incorporated
and Aflac
unsecured revolving
5 years
April 4, 2023, or the date commitments are terminated pursuant to an event of default
55.0 billion yen, or the equivalent amount in U.S. dollars
0.0 billion yen
A rate per annum equal to, at the Company's option, either, (a) London Interbank Offered Rate (LIBOR) adjusted for certain costs or (b) a base rate determined by reference to the highest of (1) the federal funds rate plus 1/2 of 1%, (2) the rate of interest for such day announced by Mizuho Bank, Ltd. as its prime rate, or (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin
No later than April 4, 2023
.085% to
.225%, depending on the Parent Company's debt ratings as of the date of determination
General corporate purposes, including a capital contingency plan for the operations of the Parent Company
Aflac Incorporated
and Aflac
uncommitted bilateral
None specified
None specified
$50 million
$0 million
A rate per annum equal to, at the Parent Company's option, either (a) a eurocurrency rate determined by reference to the agent's LIBOR for the interest period relevant to such borrowing or (b) the base rate determined by reference to the greater of (i) the prime rate as determined by the agent, and (ii) the sum of 0.50% and the federal funds rate for such day
Up to 3 months
None
General corporate purposes
Aflac(1)
uncommitted revolving
364 days
November 29, 2019
$250 million
$0 million
USD three-month LIBOR plus 75 basis points per annum
3 months
None
General corporate purposes
Aflac Incorporated(1)
uncommitted revolving
364 days
April 2, 2019
50.0 billion yen
0.0 billion yen
Three-month TIBOR plus 80 basis points per annum
3 months
None
General corporate purposes
v3.10.0.1
INCOME TAXES (Tables)
 12 Months Ended
Dec. 31, 2018
Income Tax Disclosure [Abstract]  
Schedule of Components of Income Tax Expense (Benefit) The components of income tax expense (benefit) applicable to pretax earnings for the years ended December 31 were as follows:
(In millions)
Foreign
 
U.S.
 
Total
2018:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
771

 
 
 
$
608

 
 
 
$
1,379

 
Deferred
 
93

 
 
 
(409
)
 
 
 
(316
)
 
Total income tax expense
 
$
864

 
 
 
$
199

 
 
 
$
1,063

 
2017:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
722

 
 
 
$
(91
)
 
 
 
$
631

 
Deferred
 
(24
)
 
 
 
(1,193
)
 
 
 
(1,217
)
 
Total income tax expense
 
$
698

 
 
 
$
(1,284
)
 
 
 
$
(586
)
 
2016:
 
 
 
 
 
 
 
 
 
 
 
Current
 
$
650

 
 
 
$
234

 
 
 
$
884

 
Deferred
 
136

 
 
 
388

 
 
 
524

 
Total income tax expense
 
$
786

 
 
 
$
622

 
 
 
$
1,408

 
Schedule of Effective Income Tax Rate Reconciliation The principal reasons for the differences and the related tax effects for the years ended December 31 were as follows:
(In millions)
2018
 
2017
 
2016
Income taxes based on U.S. statutory rates
 
$
836

 
 
 
$
1,406

 
 
 
$
1,424

 
Foreign rate differential
 
220


 

0

 
 
 
0

 
Write-down of U.S. deferred tax liabilities for tax reform change
 
0

 
 
 
(1,933
)
 
 
 
0

 
Utilization of foreign tax credit
 
(3
)
 
 
 
(27
)
 
 
 
(30
)
 
Nondeductible expenses
 
21

 
 
 
10

 
 
 
8

 
Other, net
 
(11
)
 
 
 
(42
)
 
 
 
6

 
Income tax expense
 
$
1,063

 
 
 
$
(586
)
 
 
 
$
1,408

 
Schedule of Income Tax Expense Benefit Intraperiod Tax Allocation Total income tax expense for the years ended December 31 was allocated as follows:
(In millions)
2018
 
2017
 
2016
Statements of earnings
 
$
1,063

 
 
 
$
(586
)
 
 
 
$
1,408

 
Other comprehensive income (loss):
 
 
 
 
 
 
 
 
 
 
 
Unrealized foreign currency translation gains (losses) during period
 
10

 
 
 
52

 
 
 
70

 
Unrealized gains (losses) on investment securities:
 
 
 
 
 
 
 
 
 
 
 
Unrealized holding gains (losses) on investment
securities during period
 
(787
)
 
 
 
575

 
 
 
962

 
Reclassification adjustment for realized (gains) losses
on investment securities included in net earnings
 
(12
)
 
 
 
1

 
 
 
18

 
Unrealized gains (losses) on derivatives during period
 
0

 
 
 
0

 
 
 
1

 
Pension liability adjustment during period
 
(8
)
 
 
 
3

 
 
 
(16
)
 
Total income tax expense (benefit) related to items of
other comprehensive income (loss)
 
(797
)
 
 
 
631

 
 
 
1,035

 
Additional paid-in capital (exercise of stock options)
 
0

 
 
 
0

 
 
 
(10
)
 
Total income taxes
 
$
266

 
 
 
$
45

 
 
 
$
2,433

 
Schedule of Deferred Tax Assets and Liabilities The income tax effects of the temporary differences that gave rise to deferred income tax assets and liabilities as of December 31 were as follows:
(In millions)
2018
 
2017
Deferred income tax liabilities:
 
 
 
 
 
 
 
Deferred policy acquisition costs
 
$
3,404

 
 
 
$
3,285

 
Unrealized gains and other basis differences on investments
 
1,307

 
 
 
2,882

 
Premiums receivable
 
149

 
 
 
104

 
Policy benefit reserves
 
3,828

 
 
 
3,557

 
Total deferred income tax liabilities
 
8,688

 
 
 
9,828

 
Deferred income tax assets:
 
 
 
 
 
 
 
Unfunded retirement benefits
 
8

 
 
 
8

 
Other accrued expenses
 
40

 
 
 
141

 
Policy and contract claims
 
775

 
 
 
870

 
Foreign currency loss on Aflac Japan
 
38

 
 
 
67

 
Deferred compensation
 
163

 
 
 
155

 
Capital loss carryforwards
 
5

 
 
 
0

 
Depreciation
 
119

 
 
 
114

 
Anticipatory foreign tax credit
 
4,040

 
 
 
4,504

 
Deferred foreign tax credit
 
591

 
 
 
0

 
Other
 
150

 
 
 
57

 
Total deferred income tax assets before valuation allowance
 
5,929

 
 
 
5,916

 
Valuation allowance
 
(738
)
 
 
 
(657
)
 
Total deferred income tax assets after valuation allowance
 
5,191

 
 
 
5,259

 
Net deferred income tax liability
 
3,497

 
 
 
4,569

 
Current income tax liability
 
523

 
 
 
176

 
Total income tax liability
 
$
4,020

 
 
 
$
4,745

 
Summary of Income Tax Contingencies A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows for the years ended December 31:
(In millions)
 
2018
 
 
2017
 
Balance, beginning of year
 
$
14


 
$
294


Additions for tax positions of prior years
 
1

  
 
0

  
Reductions for tax positions of prior years
 
0

  
 
(280
)
 
Balance, end of year
 
$
15


 
$
14
v3.10.0.1
SHAREHOLDERS' EQUITY (Tables)
 12 Months Ended
Dec. 31, 2018
Stockholders' Equity Note [Abstract]  
Schedule of Common Stock Outstanding Roll Forward The following table is a reconciliation of the number of shares of the Company's common stock for the years ended December 31.
(In thousands of shares)
2018
 
2017
 
2016
Common stock - issued:
 
 
 
 
 
Balance, beginning of period
1,345,762
 
1,342,498
 
1,339,446
Exercise of stock options and issuance of restricted shares
1,778
 
3,264
 
3,052
Balance, end of period
1,347,540
 
1,345,762
 
1,342,498
Treasury stock:
 
 
 
 
 
Balance, beginning of period
564,852
 
530,877
 
490,686
Purchases of treasury stock:
 
 
 
 
 
Open market
28,949
 
35,510
 
43,236
Other
392
 
1,018
 
662
Dispositions of treasury stock:
 
 
 
 
 
Shares issued to AFL Stock Plan
(1,306)
 
(1,782)
 
(2,130)
Exercise of stock options
(519)
 
(734)
 
(1,366)
Other
(114)
 
(37)
 
(211)
Balance, end of period
592,254
 
564,852
 
530,877
Shares outstanding, end of period
755,286
 
780,910
 
811,621
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share The following table presents the approximate number of share-based awards to purchase shares, on a weighted-average basis, that were considered to be anti-dilutive and were excluded from the calculation of diluted earnings per share at December 31:
(In thousands)
2018
 
2017
 
2016
Anti-dilutive share-based awards
 
44

 
 
 
510

 
 
 
1,822

 
Schedule of Weighted Average Number of Shares The weighted-average shares used in calculating earnings per share for the years ended December 31 were as follows: 
(In thousands of shares)
2018
 
2017
 
2016
Weighted-average outstanding shares used for calculating basic EPS
769,588

 
792,042

 
822,942

Dilutive effect of share-based awards
5,062

 
5,819

 
4,899

Weighted-average outstanding shares used for calculating diluted EPS
774,650

 
797,861

 
827,841
Changes in Accumulated Other Comprehensive Income (Loss) The tables below are reconciliations of accumulated other comprehensive income by component for the years ended December 31.

Changes in Accumulated Other Comprehensive Income
2018
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension
Liability
Adjustment
 
Total
Balance, beginning of period
 
$
(1,750
)
 
 
 
$
5,964

 
 
 
$
(23
)
 
 
 
$
(163
)
 
 
 
$
4,028

 
Cumulative effect of change
in accounting principle -
financial instruments
 
0

 
 
 
(148
)
 
 
 
0

 
 
 
0

 
 
 
(148
)
 
Cumulative effect of change
in accounting principle -
tax effects from tax reform
 
(325
)
 
 
 
734

 
 
 
(3
)
 
 
 
(32
)
 
 
 
374

 
Other comprehensive
income (loss) before
reclassification
 
228

 
 
 
(2,350
)
 
 
 
2

 
 
 
(30
)
 
 
 
(2,150
)
 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
34

 
 
 
0

 
 
 
13

 
 
 
47

 
Net current-period other
comprehensive
income (loss)
 
228

 
 
 
(2,316
)
 
 
 
2

 
 
 
(17
)
 
 
 
(2,103
)
 
Balance, end of period
 
$
(1,847
)
 
 
 
$
4,234

 
 
 
$
(24
)
 
 
 
$
(212
)
 
 
 
$
2,151

 
All amounts in the table above are net of tax.
2017
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension Liability Adjustment
 
Total
Balance, beginning of period
 
$
(1,983
)
 
 
 
$
4,805

 
 
 
$
(24
)
 
 
 
$
(168
)
 
 
 
$
2,630

 
Other comprehensive
income (loss) before
reclassification
 
233

 
 
 
1,158

 
 
 
1

 
 
 
(6
)
 
 
 
1,386

 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
1

 
 
 
0

 
 
 
11

 
 
 
12

 
Net current-period other
comprehensive
income (loss)
 
233

 
 
 
1,159

 
 
 
1

 
 
 
5

 
 
 
1,398

 
Balance, end of period
 
$
(1,750
)
 
 
 
$
5,964

 
 
 
$
(23
)
 
 
 
$
(163
)
 
 
 
$
4,028

 
All amounts in the table above are net of tax.

2016
(In millions)
Unrealized Foreign
Currency Translation
Gains (Losses)
 
Unrealized
Gains (Losses)
on Investment Securities
 
Unrealized
Gains (Losses)
on Derivatives
 
Pension Liability Adjustment
 
Total
Balance, beginning of period
 
$
(2,196
)
 
 
 
$
2,986

 
 
 
$
(26
)
 
 
 
$
(139
)
 
 
 
$
625

 
Other comprehensive
income (loss) before
reclassification
 
213

 
 
 
1,854

 
 
 
2

 
 
 
(32
)
 
 
 
2,037

 
Amounts reclassified from
accumulated other
comprehensive income
(loss)
 
0

 
 
 
(35
)
 
 
 
0

 
 
 
3

 
 
 
(32
)
 
Net current-period other
comprehensive
income (loss)
 
213

 
 
 
1,819

 
 
 
2

 
 
 
(29
)
 
 
 
2,005

 
Balance, end of period
 
$
(1,983
)
 
 
 
$
4,805

 
 
 
$
(24
)
 
 
 
$
(168
)
 
 
 
$
2,630

 
All amounts in the table above are net of tax.
Reclassification out of Accumulated Other Comprehensive Income The tables below summarize the amounts reclassified from each component of accumulated other comprehensive income based on source for the years ended December 31.

Reclassifications Out of Accumulated Other Comprehensive Income
(In millions)
2018
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(63
)
 
Other-than-temporary impairment
losses realized
 
 
17

 
Other gains (losses)
 
 
(46
)
 
Total before tax
 
 
12

 
Tax (expense) or benefit(1)
 
 
$
(34
)
 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(18
)
 
Acquisition and operating expenses(2)
Prior service (cost) credit
 
0

 
Acquisition and operating expenses(2)
 
 
5

 
Tax (expense) or benefit(1)
 
 
$
(13
)
 
Net of tax
Total reclassifications for the period
 
$
(47
)
 
Net of tax

(1) Based on 27% blended tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see
Note 14 for additional details).
 
(In millions)
2017
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(29
)
 
Other-than-temporary impairment
losses realized
 
 
27

 
Other gains (losses)
 
 
(2
)
 
Total before tax
 
 
1

 
Tax (expense) or benefit(1)
 
 
$
(1
)
 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(17
)
 
Acquisition and operating expenses(2)
Prior service (cost) credit
 
0

 
Acquisition and operating expenses(2)
 
 
6

 
Tax (expense) or benefit(1)
 
 
$
(11
)
 
Net of tax
Total reclassifications for the period
 
$
(12
)
 
Net of tax
(1) Based on 35% tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).
(In millions)
2016
 
Details about Accumulated Other Comprehensive Income Components
Amount Reclassified from Accumulated Other Comprehensive Income
Affected Line Item in the
Statements of Earnings
Unrealized gains (losses) on available-for-sale
securities
 
$
(83
)
 
Other-than-temporary impairment
losses realized
 
 
136

 
Other gains (losses)
 
 
53

 
Total before tax
 
 
(18
)
 
Tax (expense) or benefit(1)
 
 
$
35

 
Net of tax
Amortization of defined benefit pension items:
 
 
 
 
       Actuarial gains (losses)
 
$
(15
)
 
Acquisition and operating expenses(2)
       Prior service (cost) credit
 
11

 
Acquisition and operating expenses(2)
 
 
1

 
Tax (expense) or benefit(1)
 
 
$
(3
)
 
Net of tax
Total reclassifications for the period
 
$
32

 
Net of tax
(1) Based on 35% tax rate
(2) These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).
v3.10.0.1
SHARE-BASED COMPENSATION (Tables)
 12 Months Ended
Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Schedule of Expense Recognized in Connection with Share Based Awards The following table presents the impact of the expense recognized in connection with share-based awards for the periods ended December 31.
(In millions, except for per-share amounts)
2018
 
2017
 
2016
Impact on earnings from continuing operations
 
$
57

 
 
 
$
51

 
 
 
$
68

 
Impact on earnings before income taxes
 
57

 
 
 
51

 
 
 
68

 
Impact on net earnings
 
45

 
 
 
35

 
 
 
46

 
Impact on net earnings per share:
 
 
 
 
 
 
 
 
 
 
 
Basic
 
$
.06

 
 
 
$
.05

 
 
 
$
.06

 
Diluted
 
.06

 
 
 
.05

 
 
 
.06

 
Schedule of Share-based Compensation, Stock Options, Activity The following table summarizes stock option activity under the employee stock option plan.
(In thousands of shares)
Stock
Option
Shares
 
Weighted-Average
Exercise Price
Per Share
Outstanding at December 31, 2015
 
15,836

 
 
 
$
25.47

 
Granted in 2016
 
1,328

 
 
 
30.70

 
Canceled in 2016
 
(362
)
 
 
 
27.82

 
Exercised in 2016
 
(4,122
)
 
 
 
24.46

 
Outstanding at December 31, 2016
 
12,680

 
 
 
26.28

 
Granted in 2017
 
626

 
 
 
35.80

 
Canceled in 2017
 
(236
)
 
 
 
24.95

 
Exercised in 2017
 
(5,766
)
 
 
 
30.11

 
Outstanding at December 31, 2017
 
7,304

 
 
 
28.03

 
Granted in 2018
 
67

 
 
 
44.59

 
Canceled in 2018
 
(167
)
 
 
 
32.11

 
Exercised in 2018
 
(1,874
)
 
 
 
26.78

 
Outstanding at December 31, 2018
 
5,330

 
 
 
$
28.54

 
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable
(In thousands of shares)
2018
 
2017
 
2016
Shares exercisable, end of year
 
3,917

 
 
 
4,208

 
 
 
8,986

 
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions The following table presents the assumptions used in valuing options granted during the years ended December 31.
 
2018
 
2017
 
2016
Expected term (years)
 
7.0
 
 
 
5.9
 
 
 
6.4
 
Expected volatility
 
22.0
%
 
 
26.0
%
 
 
27.0
%
Annual forfeiture rate
 
3.6
 
 
 
3.4
 
 
 
3.2
 
Risk-free interest rate
 
2.5
 
 
 
2.5
 
 
 
2.2
 
Dividend yield
 
2.4
 
 
 
2.5
 
 
 
2.9
 
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range The following table summarizes information about stock options outstanding and exercisable at December 31, 2018.
(In thousands of shares)
 
 
Options Outstanding
 
Options Exercisable
 
Range of
Exercise Prices
Per Share
 
 
Stock Option
Shares
Outstanding
 
Wgtd.-Avg.
Remaining
Contractual
Life (Yrs.)
 
Wgtd.-Avg.
Exercise
Price
Per Share
 
Stock Option
Shares
Exercisable
 
Wgtd.-Avg.
Exercise
Price
Per Share
 
$
11.07

-
$
24.28

 
 
 
1,181

 
 
 
1.8
 
 
 
$
20.76

 
 
 
1,181

 
 
 
$
20.76

 
 
24.75

-
28.97

 
 
 
1,718

 
 
 
4.8
 
 
 
27.76

 
 
 
1,026

 
 
 
26.95

 
 
29.04

-
31.21

 
 
 
1,226

 
 
 
5.8
 
 
 
30.77

 
 
 
1,221

 
 
 
30.77

 
 
31.22

-
37.22

 
 
 
1,134

 
 
 
7.5
 
 
 
34.44

 
 
 
488

 
 
 
33.86

 
 
38.76

-
44.59

 
 
 
71

 
 
 
9.3
 
 
 
44.21

 
 
 
1

 
 
 
38.76

 
 
$
11.07

-
$
44.59

 
 
 
5,330

 
 
 
5.0
 
 
 
$
28.54

 
 
 
3,917

 
 
 
$
27.14

 
Schedule of Cash Proceeds Received from Share-based Payment Awards The following table summarizes stock option activity during the years ended December 31.
(In millions)
2018
 
2017
 
2016
Total intrinsic value of options exercised
 
$
34

 
 
 
$
87

 
 
 
$
41

 
Cash received from options exercised
 
48

 
 
 
58

 
 
 
68

 
Tax benefit realized as a result of options exercised and
restricted stock releases
 
25

 
 
 
74

 
 
 
45

 
Schedule of Share-based Payment Award, Performance Based Restricted Stock, Valuation Assumptions Key assumptions used to value PBRS granted during 2018 follows:
(In millions)
2018
 
Expected volatility (based on Aflac Inc. and peer group historical daily stock price)
 
16.48
%
 
 
Expected life from grant date (years)
 
2.9

 
 
Risk-free interest rate (based on U.S. Treasury yields at the date of grant)
 
2.29
%
 
 
Schedule of Nonvested Restricted Stock Units Activity The value of restricted stock awards and restricted stock units is based on the fair market value of our common stock at the date of grant. The following table summarizes restricted stock activity during the years ended December 31. 
(In thousands of shares)
Shares
 
Weighted-Average
Grant-Date
Fair Value
Per  Share
Restricted stock at December 31, 2015
 
3,630

 
 
 
$
29.21

 
Granted in 2016
 
1,756

 
 
 
30.84

 
Canceled in 2016
 
(152
)
 
 
 
30.33

 
Vested in 2016
 
(1,498
)
 
 
 
26.84

 
Restricted stock at December 31, 2016
 
3,736

 
 
 
30.88

 
Granted in 2017
 
1,118

 
 
 
36.48

 
Canceled in 2017
 
(202
)
 
 
 
32.23

 
Vested in 2017
 
(1,018
)
 
 
 
31.09

 
Restricted stock at December 31, 2017
 
3,634

 
 
 
32.40

 
Granted in 2018
 
1,121

 
 
 
44.27

 
Canceled in 2018
 
(105
)
 
 
 
34.39

 
Vested in 2018
 
(1,243
)
 
 
 
31.64

 
Restricted stock at December 31, 2018
 
3,407

 
 
 
$
36.52

 
v3.10.0.1
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS (Tables)
 12 Months Ended
Dec. 31, 2018
Insurance [Abstract]  
Reconciliation of Capital and Surplus between NAIC and Nebraska state basis A reconciliation of Aflac's capital and surplus between SAP and practices permitted by the state of Nebraska is shown below for the years ended December 31:
(In millions)
2018
 
2017
Capital and surplus, Nebraska state basis
 
$
2,600

 
 
 
$
11,001

 
State Permitted Practice:
 
 
 
 
 
 
 
Refundable lease deposits – Japan
 
0

 
 
 
(43
)
 
Reinsurance - Japan
 
0

 
 
 
(818
)
 
Capital and surplus, NAIC basis
 
$
2,600

 
 
 
$
10,140

 
Profit Remittances Disclosure Profits remitted by Aflac Japan to the Parent Company, after April 1, 2018, and to Aflac U.S., prior to April 1, 2018, were as follows for the years ended December 31:
  
In Dollars
 
In Yen
(In millions of dollars and billions of yen)
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Profit remittances
 
$
808

 
 
 
$
1,150

 
 
 
$
1,286

 
 
 
89.7

 
 
 
129.3

 
 
 
138.5

 
v3.10.0.1
BENEFIT PLANS (Tables)
 12 Months Ended
Dec. 31, 2018
Schedule of Net Funded Status Information with respect to the Company's benefit plans' assets and obligations as of December 31 was as follows:

 
 
Pension Benefits
 
Other
 
 
Japan
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
2017
 
2018
2017
 
2018
2017
Projected benefit obligation:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Benefit obligation, beginning of year
 
 
$
341

 
 
$
329

 
 
 
$
908

 
 
$
798

 
 
 
$
36

 
 
$
37

 
      Service cost
 
 
19

 
 
20

 
 
 
27

 
 
24

 
 
 
0

 
 
0

 
      Interest cost
 
 
7

 
 
6

 
 
 
31

 
 
40

 
 
 
1

 
 
1

 
      Actuarial (gain) loss
 
 
35

 
 
(10
)
 
 
 
(69
)
 
 
65

 
 
 
4

 
 
0

 
      Benefits and expenses paid
 
 
(11
)
 
 
(14
)
 
 
 
(22
)
 
 
(19
)
 
 
 
(4
)
 
 
(2
)
 
      Effect of foreign exchange
rate changes
 
 
5

 
 
10

 
 
 
0

 
 
0

 
 
 
0

 
 
0

 
               Benefit obligation, end of year
 
 
396

 
 
341

 
 
 
875

 
 
908

 
 
 
37

 
 
36

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Plan assets:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Fair value of plan assets,
beginning of year
 
 
270

 
 
229

 
 
 
448

 
 
359

 
 
 
0

 
 
0

 
      Actual return on plan assets
 
 
(9
)
 
 
16

 
 
 
(30
)
 
 
61

 
 
 
0

 
 
0

 
      Employer contributions
 
 
34

 
 
32

 
 
 
69

 
 
47

 
 
 
4

 
 
2

 
      Benefits and expenses paid
 
 
(11
)
 
 
(14
)
 
 
 
(22
)
 
 
(19
)
 
 
 
(4
)
 
 
(2
)
 
      Effect of foreign exchange
rate changes
 
 
5

 
 
7

 
 
 
0

 
 
0

 
 
 
0

 
 
0

 
               Fair value of plan assets, end of year
 
 
289

 
 
270

 
 
 
465

 
 
448

 
 
 
0

 
 
0

 
Funded status of the plans(1)
 
 
$
(107
)
 
 
$
(71
)
 
 
 
$
(410
)
 
 
$
(460
)
 
 
 
$
(37
)
 
 
$
(36
)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Amounts recognized in accumulated other
comprehensive income:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
      Net actuarial (gain) loss
 
 
$
95

 
 
$
44

 
 
 
$
174

 
 
$
203

 
 
 
$
9

 
 
$
6

 
      Prior service (credit) cost
 
 
(2
)
 
 
(2
)
 
 
 
(4
)
 
 
(4
)
 
 
 
0

 
 
0

 
               Total included in accumulated
other comprehensive income
 
 
$
93

 
 
$
42

 
 
 
$
170

 
 
$
199

 
 
 
$
9

 
 
$
6

 
Accumulated benefit obligation
 
 
$
356

 
 
$
307

 
 
 
$
746

 
 
$
756

 
 
 
  N/A

(2) 
 
N/A

(2) 
(1) Recognized in other liabilities in the consolidated balance sheets
(2) Not applicable
Schedule of Assumptions Used
 
Pension Benefits
 
Other
 
Japan
 
 
U.S.
 
 
Postretirement Benefits
 
2018
 
2017
 
2016
 
 
2018
 
2017
 
2016
 
 
2018
 
2017
 
2016
 
Weighted-average actuarial assumptions:
  
 
  
 
  
 
 
  
 
  
 
  
 
  
  
 
  
 
  
  
Discount rate - net periodic benefit cost
1.25
%
 
1.25
%
 
1.75
%
 
 
3.75
%
 
4.25
%
 
4.50
%
 
 
3.75
%
 
4.25
%
 
4.50
%
 
Discount rate - benefit obligations
1.25

 
1.25

 
1.25

 
 
4.25

 
3.75

 
4.25

 
  
4.25

 
3.75

 
4.25

  
Expected long-term return on plan assets
2.00

 
2.00

 
2.00

 
 
6.50

 
6.75

 
7.00

 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
Rate of compensation increase
N/A
(1) 
N/A
(1) 
N/A
(1) 
 
4.00

 
4.00

 
4.00

 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
Health care cost trend rates
N/A
(1) 
N/A
(1) 
N/A
(1) 
 
N/A
(1) 
N/A
(1) 
N/A
(1) 
  
7.40

(2) 
5.40

(2) 
5.20

(2) 
(1) Not applicable(2)For the years 2018, 2017 and 2016, the health care cost trend rates are expected to trend down to 4.1% in 61 years, 4.5% in 77 years, and 4.5% in 74 years, respectively.
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates A one-percentage point increase and decrease in assumed health care cost trend rates would have the following effects as of December 31, 2018:
(In millions)
 
 
 
 
One percentage point increase:
 
 
 
 
Increase in total service and interest costs
 
 
$
0

 
Increase in postretirement benefit obligation
 
 
1

 
 
 
 
 
 
One percentage point decrease:
 
 
 
 
Decrease in total service and interest costs
 
 
$
0

 
Decrease in postretirement benefit obligation
 
 
1

 
Schedule of Net Benefit Costs Pension and other postretirement benefit expenses are included in acquisition and operating expenses in the consolidated statements of earnings, which includes $25 million, $35 million and $17 million of other components of net periodic pension cost and postretirement costs (other than services costs) for the years ended December 31, 2018, 2017 and 2016, respectively. Total net periodic benefit cost includes the following components:
 
 
Pension Benefits
 
Other
 
 
 
Japan
 
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Service cost
 
 
$
19

 
 
 
$
20

 
 
 
$
16

 
 
 
$
27

 
 
 
$
24

 
 
 
$
23

 
 
 
$
0

 
 
 
$
0

 
 
 
$
1

 
Interest cost
 
 
7

 
 
 
6

 
 
 
9

 
 
 
31

 
 
 
40

 
 
 
29

 
 
 
1

 
 
 
1

 
 
 
2

 
Expected return on plan
assets
 
 
(6
)
 
 
 
(5
)
 
 
 
(4
)
 
 
 
(26
)
 
 
 
(24
)
 
 
 
(23
)
 
 
 
0

 
 
 
0

 
 
 
0

 
Amortization of net actuarial
loss
 
 
1

 
 
 
2

 
 
 
1

 
 
 
16

 
 
 
14

 
 
 
13

 
 
 
1

 
 
 
1

 
 
 
1

 
Amortization of prior service
cost (credit)
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
(11
)
 
Net periodic (benefit) cost
 
 
$
21

 
 
 
$
23

 
 
 
$
22

 
 
 
$
48

 
 
 
$
54

 
 
 
$
42

 
 
 
$
2

 
 
 
$
2

 
 
 
$
(7
)
 
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) The following table summarizes the amounts recognized in other comprehensive loss (income) for the years ended December 31:
 
 
Pension Benefits
 
Other
 
 
Japan
 
U.S.
 
Postretirement Benefits
(In millions)
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
 
2018
 
2017
 
2016
Net actuarial loss (gain)
 
 
$
52

 
 
 
$
(21
)
 
 
 
$
26

 
 
 
$
(13
)
 
 
 
$
28

 
 
 
$
27

 
 
 
$
4

 
 
 
$
0

 
 
 
$
(4
)
 
Amortization of net actuarial loss
 
 
(1
)
 
 
 
(2
)
 
 
 
(1
)
 
 
 
(16
)
 
 
 
(14
)
 
 
 
(13
)
 
 
 
(1
)
 
 
 
(1
)
 
 
 
(1
)
 
Amortization of prior
service cost
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
0

 
 
 
11

 
     Total
 
 
$
51

 
 
 
$
(23
)
 
 
 
$
25

 
 
 
$
(29
)
 
 
 
$
14

 
 
 
$
14

 
 
 
$
3

 
 
 
$
(1
)
 
 
 
$
6

 
Schedule of Expected Benefit Payments The following table provides expected benefit payments, which reflect expected future service, as appropriate.
 
 
Pension Benefits
 
Other
(In millions)
 
Japan
U.S.
 
Postretirement Benefits
2019
 
 
$
12

 
 
$
25

 
 
 
$
3

 
2020
 
 
12

 
 
26

 
 
 
3

 
2021
 
 
12

 
 
27

 
 
 
4

 
2022
 
 
19

 
 
36

 
 
 
4

 
2023
 
 
15

 
 
34

 
 
 
4

 
2024-2028
 
 
89

 
 
199

 
 
 
17

 
Schedule of Allocation of Plan Assets Asset allocation targets as of December 31, 2018 were as follows:
 
 
Japan Pension
 
U.S. Pension
Domestic equities
 
 
5
%
 
 
 
40
%
 
International equities
 
 
18

 
 
 
20

 
Fixed income securities
 
 
66

 
 
 
40

 
Other
 
 
11

 
 
 
0

 
     Total
 
 
100
%
 
 
 
100
%
 
Plan Assets  
Fair Value, Assets Measured on Recurring Basis The following table presents the fair value of Aflac Japan's pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 2 in the fair value hierarchy.
(In millions)
2018
 
2017
Japan pension plan assets:
 
 
 
 
 
 
 
     Equities:
 
 
 
 
 
 
 
        Japanese equity securities
 
$
14

 
 
 
$
37

 
        International equity securities
 
50

 
 
 
50

 
     Fixed income securities:
 
 
 
 
 
 
 
        Japanese bonds
 
34

 
 
 
91

 
        International bonds
 
160

 
 
 
62

 
     Insurance contracts
 
31

 
 
 
30

 
        Total
 
$
289

 
 
 
$
270

 

The following table presents the fair value of Aflac U.S.'s pension plan assets that are measured at fair value on a recurring basis as of December 31. All of these assets are classified as Level 1 in the fair value hierarchy.
(In millions)
2018
 
2017
U.S. pension plan assets:
 
 
 
 
 
 
 
     Mutual funds:
 
 
 
 
 
 
 
        Large cap equity funds
 
$
120

 
 
 
$
124

 
        Mid cap equity funds
 
17

 
 
 
22

 
        Real estate equity funds
 
13

 
 
 
13

 
        International equity funds
 
92

 
 
 
108

 
        Fixed income bond funds
 
179

 
 
 
175

 
     Aflac Incorporated common stock
 
5

 
 
 
5

 
     Cash and cash equivalents
 
39

 
 
 
1

 
        Total
 
$
465

 
 
 
$
448

 
v3.10.0.1
COMMITMENTS AND CONTINGENT LIABILITIES (Tables)
 12 Months Ended
Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]  
Schedule of Future Minimum Rental Payments for Operating Leases Future minimum lease payments due under non-cancelable operating leases at December 31, 2018, were as follows:

(In millions)
 
2019
$
63

2020
47

2021
35

2022
31

2023
8

Thereafter
18

   Total future minimum lease payments
$
202
v3.10.0.1
Unaudited Consolidated Quarterly Financial Data (Tables)
 12 Months Ended
Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]  
Schedule of Quarterly Financial Information In management's opinion, the following quarterly financial information fairly presents the results of operations for such periods and is prepared on a basis consistent with the Company's annual audited financial statements.
 
(In millions, except for per-share amounts)
March 31,
2018
 
June 30,
2018
 
September 30,
2018
 
December 31,
2018
Net premium income
 
$
4,745

 
 
 
$
4,706

 
 
 
$
4,636

 
 
 
$
4,591

 
Net investment income
 
837

 
 
 
862

 
 
 
870

 
 
 
874

 
Realized investment gains (losses)
 
(134
)
 
 
 
3

 
 
 
56

 
 
 
(355
)
 
Other income (loss)
 
16

 
 
 
18

 
 
 
15

 
 
 
16

 
Total revenues
 
5,464

 
 
 
5,589

 
 
 
5,577

 
 
 
5,126

 
Total benefits and expenses
 
4,482

 
 
 
4,458

 
 
 
4,431

 
 
 
4,404

 
Earnings before income taxes
 
982

 
 
 
1,131

 
 
 
1,146

 
 
 
722

 
Total income tax
 
265

 
 
 
299

 
 
 
301

 
 
 
197

 
Net earnings
 
$
717

 
 
 
$
832

 
 
 
$
845

 
 
 
$
525

 
Net earnings per basic share
 
$
.92

 
 
 
$
1.08

 
 
 
$
1.10

 
 
 
$
.69

 
Net earnings per diluted share
 
.91

 
 
 
1.07

 
 
 
1.09

 
 
 
.69

 
Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
(In millions, except for per-share amounts)
March 31,
2017
 
June 30,
2017
 
September 30,
2017
 
December 31,
2017
Net premium income
 
$
4,638

 
 
 
$
4,665

 
 
 
$
4,648

 
 
 
$
4,580

 
Net investment income
 
794

 
 
 
802

 
 
 
811

 
 
 
812

 
Realized investment gains (losses)
 
(140
)
 
 
 
(56
)
 
 
 
30

 
 
 
15

 
Other income (loss)
 
17

 
 
 
17

 
 
 
17

 
 
 
17

 
Total revenues
 
5,309

 
 
 
5,428

 
 
 
5,506

 
 
 
5,424

 
Total benefits and expenses
 
4,411

 
 
 
4,383

 
 
 
4,431

 
 
 
4,425

 
Earnings before income taxes
 
898

 
 
 
1,045

 
 
 
1,075

 
 
 
999

 
Total income tax
 
306

 
 
 
332

 
 
 
359

 
 
 
(1,585
)
 
Net earnings
 
$
592

 
 
 
$
713

 
 
 
$
716

 
 
 
$
2,584

 
Net earnings per basic share
 
$
.74

 
 
 
$
.90

 
 
 
$
.91

 
 
 
$
3.29

 
Net earnings per diluted share
 
.73

 
 
 
.89

 
 
 
.90

 
 
 
3.27

 

Quarterly amounts may not agree in total to the corresponding annual amounts due to rounding.
v3.10.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Summary of Signficant Accounting Policies - Additional Information (Detail)
$ in Millions
 12 Months Ended
Feb. 13, 2018
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Jan. 01, 2019
USD ($)
Jan. 01, 2018
USD ($)
Dec. 31, 2015
USD ($)
Significant Accounting Policies [Line Items]              
Stock split, conversion ratio 2            
Common stock as a percentage of two-for-one stock split dividend 100.00%            
Aflac Japan              
Significant Accounting Policies [Line Items]              
Percentage of the Company assets   84.00% 83.00%        
Aflac Japan's percentage of the Company's total revenues   70.00% 70.00% 71.00%      
Accounting Standards Update 2015-03              
Significant Accounting Policies [Line Items]              
New accounting pronouncement or change in accounting principle, cumulative effect of change on liabilities             $ 40
Accumulated other comprehensive income (loss) | Accounting Standards Update 2016-01              
Significant Accounting Policies [Line Items]              
Cumulative effect of change in accounting principle, net of income taxes   $ (148) [1] $ 0 [1] $ 0 [1]   $ (148)  
Accumulated other comprehensive income (loss) | Accounting Standards Update 2018-02              
Significant Accounting Policies [Line Items]              
Cumulative effect of change in accounting principle, net of income taxes   374 [1] 0 [1] 0 [1]   374  
Retained earnings | Accounting Standards Update 2016-01              
Significant Accounting Policies [Line Items]              
Cumulative effect of change in accounting principle, net of income taxes   148 [1] 0 [1] 0 [1]   148  
Retained earnings | Accounting Standards Update 2018-02              
Significant Accounting Policies [Line Items]              
Cumulative effect of change in accounting principle, net of income taxes   $ (374) [1] $ 0 [1] $ 0 [1]   $ (374)  
Scenario, Forecast | Lower Limit | Accounting Standards Update 2016-02              
Significant Accounting Policies [Line Items]              
New accounting pronouncement or change in accounting principle cumulative effect of change on assets         $ 100    
New accounting pronouncement or change in accounting principle, cumulative effect of change on liabilities         100    
Scenario, Forecast | Upper Limit | Accounting Standards Update 2016-02              
Significant Accounting Policies [Line Items]              
New accounting pronouncement or change in accounting principle cumulative effect of change on assets         200    
New accounting pronouncement or change in accounting principle, cumulative effect of change on liabilities         $ 200    
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018.
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Additional Information (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2018
USD ($)
segment
Dec. 31, 2017
USD ($)
Segment Reporting Information [Line Items]    
Reportable insurance business segments | segment 2  
Total receivables related to Aflac Japan's operations $ 851 $ 827
Aflac Japan    
Segment Reporting Information [Line Items]    
Total receivables related to Aflac Japan's operations $ 334 $ 334
Percentage of total receivables related to Aflac Japan's operations 39.20% 40.40%
Maximum | Machinery and equipment    
Segment Reporting Information [Line Items]    
Property, Plant and Equipment, Useful Life 20 years  
Maximum | Building    
Segment Reporting Information [Line Items]    
Property, Plant and Equipment, Useful Life 50 years  
Maximum | Furniture and fixtures    
Segment Reporting Information [Line Items]    
Property, Plant and Equipment, Useful Life 20 years  
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Revenues (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance $ 4,591 $ 4,636 $ 4,706 $ 4,745 $ 4,580 $ 4,648 $ 4,665 $ 4,638 $ 18,677 $ 18,531 $ 19,225
Net investment income 874 870 862 837 812 811 802 794 3,442 3,220 3,278
Total revenues $ 5,126 $ 5,577 $ 5,589 $ 5,464 $ 5,424 $ 5,506 $ 5,428 $ 5,309 21,758 21,667 22,559
Total adjusted revenues                 21,988 21,589 22,387
Realized investment gains (losses) [1],[2],[3]                 (230) 78 172
Gain (loss) on change in fair value of derivative, corporate                 36    
Life insurance                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 3,674 4,034 4,740
Aflac Japan                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 12,762 12,752 13,537
Net investment income, less amortized hedge costs                 2,403 2,235 2,368
Other income (loss)                 41 41 40
Net investment income                 2,639 2,463 2,554
Total revenues                 15,206 15,028 15,945
Hedge cost                 236 228 186
Aflac Japan | Cancer                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 5,849 5,612 5,639
Aflac Japan | Medical and other health                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 3,516 3,379 3,429
Aflac Japan | Life insurance                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 3,397 3,761 4,469
Aflac U.S.                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 5,708 5,563 5,454
Other income (loss)                 8 5 10
Net investment income                 727 721 703
Total revenues                 6,443 6,289 6,167
Aflac U.S. | Cancer                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 1,311 1,308 1,299
Aflac U.S. | Life insurance                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 278 273 271
Aflac U.S. | Accident and disability                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 2,611 2,537 2,469
Aflac U.S. | Other health                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Net premiums, principally supplemental health insurance                 1,508 1,445 1,415
Corporate and other                      
Segment Reporting, Revenue Reconciling Item [Line Items]                      
Total revenues                 $ 339 $ 272 $ 275
[1] Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in net investment income when analyzing operations.
[2] Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from net investment income when analyzing segment operations.
[3] An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Pretax Earnings (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Pretax adjusted earnings                 $ 4,354 $ 4,087 $ 4,117
Realized investment gains (losses) [1],[2],[3],[4]                 (297) 0 87
Other income (loss) [5]                 (74) (69) (137)
Earnings before income taxes $ 722 $ 1,146 $ 1,131 $ 982 $ 999 $ 1,075 $ 1,045 $ 898 3,983 4,018 4,067
Income taxes applicable to pretax adjusted earnings                 1,129 1,370 1,426
Effect of foreign currency translation on after tax adjusted earnings                 28 (41) 141
Gain (loss) on change in fair value of derivative, corporate                 36    
Gain (loss) on change in fair value of derivative, interest rate component                 67 77 85
Aflac Japan                      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Pretax adjusted earnings                 3,208 3,054 3,148
Hedge cost                 236 228 186
Aflac U.S.                      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Pretax adjusted earnings                 1,285 1,245 1,208
Corporate and other                      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Pretax adjusted earnings                 $ (139) (212) (239)
5.50% subordinated notes due September 2052                      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Expense on extinguishment of debt                   $ 13  
Senior Notes due 2039 and 2040                      
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]                      
Expense on extinguishment of debt                     $ 137
[1] Amortized hedge costs in Aflac Japan were partially offset by derivatives entered into as part of corporate activities and resulted in a benefit of $36 for 2018, which has been reclassified from realized investment gains (losses) and reported as an increase in pretax adjusted earnings when analyzing operations.
[2] Amortized hedge costs related to hedging U.S. dollar-denominated investments held in Aflac Japan were $236, $228 and $186 for 2018, 2017 and 2016, respectively, and have been reclassified from realized investment gains (losses) and reported as a deduction from pretax adjusted earnings when analyzing segment operations.
[3] Excluding a gain of $67 in 2018, $77 in 2017 and $85 in 2016, related to the interest rate component of the change in fair value of foreign currency swaps on notes payable which is included in adjusted earnings when analyzing segment operations
[4] An immaterial amount of net interest cash flows from derivatives associated with certain investment strategies in 2018, were reclassified from realized investment gains (losses) into net investment income when analyzing operations.
[5] Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Operations by Segment - Assets (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]    
Assets $ 140,406 $ 137,217
Aflac Japan    
Segment Reporting, Asset Reconciling Item [Line Items]    
Assets 118,342 114,402
Aflac U.S.    
Segment Reporting, Asset Reconciling Item [Line Items]    
Assets 19,100 19,893
Corporate and other    
Segment Reporting, Asset Reconciling Item [Line Items]    
Assets $ 2,964 $ 2,922
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Yen/Dollar Exchange Rates Used (Detail)
$ in Millions
 12 Months Ended
Dec. 31, 2018
USD ($)
¥ / $
Dec. 31, 2017
USD ($)
¥ / $
Dec. 31, 2016
USD ($)
¥ / $
Segment Reporting, Other Significant Reconciling Item [Line Items]      
Weighted-average yen/dollar exchange rate | ¥ / $ [1] 110.39 112.16 108.70
Yen percent strengthening (weakening) 1.60% (3.10%) 11.30%
Exchange effect on pretax operating earnings (in millions) $ 38 $ (63) $ 218
Yen/dollar exchange rate at December 31 | ¥ / $ [1] 111.00 113.00  
Yen percent strengthening (weakening) 1.80% 3.10%  
Exchange effect on total assets      
Segment Reporting, Other Significant Reconciling Item [Line Items]      
Exchange effect $ 1,362 $ 2,593  
Exchange effect on total liabilities      
Segment Reporting, Other Significant Reconciling Item [Line Items]      
Exchange effect $ 1,270 $ 2,848  
[1] Rates are based on the published MUFG Bank, Ltd. telegraphic transfer middle rate (TTM)
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Information on Transfers of Funds from Aflac Japan (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Segment Reporting [Abstract]      
Management fees $ 136 $ 93 $ 79
Allocated expenses 24 109 106
Profit remittances 808 1,150 1,286
Total transfers from Aflac Japan $ 968 $ 1,352 $ 1,471
v3.10.0.1
BUSINESS SEGMENT AND FOREIGN INFORMATION - Classes of Property and Equipment (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Property and equipment:    
Land $ 168 $ 168
Buildings 456 441
Equipment 400 372
Total property and equipment 1,024 981
Less accumulated depreciation 581 547
Net property and equipment $ 443 $ 434
v3.10.0.1
INVESTMENTS - Components of Net Investment Income (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Schedule of Investment Income, Reported Amounts, by Category [Line Items]                      
Gross investment income                 $ 3,590 $ 3,334 $ 3,385
Less investment expenses                 148 114 107
Net investment income $ 874 $ 870 $ 862 $ 837 $ 812 $ 811 $ 802 $ 794 3,442 3,220 3,278
Fixed maturity securities                      
Schedule of Investment Income, Reported Amounts, by Category [Line Items]                      
Gross investment income                 3,142 3,173 3,308
Equity securities                      
Schedule of Investment Income, Reported Amounts, by Category [Line Items]                      
Gross investment income                 38 42 35
Other investments                      
Schedule of Investment Income, Reported Amounts, by Category [Line Items]                      
Gross investment income                 369 94 31
Short-term investments and cash equivalents                      
Schedule of Investment Income, Reported Amounts, by Category [Line Items]                      
Gross investment income                 $ 41 $ 25 $ 11
v3.10.0.1
INVESTMENTS - Available-for-Sale Debt Securities (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost $ 76,856 [1],[2] $ 75,132 [3]
Gross Unrealized Gains 7,733 9,985
Gross Unrealized Losses 1,694 804
Fair Value [4],[5] 82,895 [1],[2] 84,313 [3]
Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 44,027 40,378
Gross Unrealized Gains 5,308 5,582
Gross Unrealized Losses 435 350
Fair Value 48,900 45,610
Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 32,829 34,754
Gross Unrealized Gains 2,425 4,403
Gross Unrealized Losses 1,259 454
Fair Value 33,995 38,703
Japan government and agencies | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 30,637 27,980
Gross Unrealized Gains 3,700 3,363
Gross Unrealized Losses 140 271
Fair Value 34,197 31,072
U.S. government and agencies | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 137 146
Gross Unrealized Gains 9 13
Gross Unrealized Losses 1 1
Fair Value 145 158
Municipalities    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 1,863 1,370
Municipalities | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 385 314
Gross Unrealized Gains 32 28
Gross Unrealized Losses 9 12
Fair Value 408 330
Municipalities | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 1,343 872
Gross Unrealized Gains 120 168
Gross Unrealized Losses 8 0
Fair Value 1,455 1,040
Mortgage- and asset-backed securities    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 339 444
Mortgage- and asset-backed securities | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 155 242
Gross Unrealized Gains 22 29
Gross Unrealized Losses 0 0
Fair Value 177 271
Mortgage- and asset-backed securities | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 155 161
Gross Unrealized Gains 8 12
Gross Unrealized Losses 1 0
Fair Value 162 173
Public utilities    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 7,171 7,954
Public utilities | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 1,732 1,635
Gross Unrealized Gains 280 352
Gross Unrealized Losses 4 6
Fair Value 2,008 1,981
Public utilities | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 4,772 5,116
Gross Unrealized Gains 496 884
Gross Unrealized Losses 105 27
Fair Value 5,163 5,973
Sovereign and supranational    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 1,260 1,909
Sovereign and supranational | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 826 1,380
Gross Unrealized Gains 123 190
Gross Unrealized Losses 0 1
Fair Value 949 1,569
Sovereign and supranational | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 251 267
Gross Unrealized Gains 60 73
Gross Unrealized Losses 0 0
Fair Value 311 340
Banks/financial institutions    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 8,918 8,933
Banks/financial institutions | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 5,440 4,742
Gross Unrealized Gains 502 811
Gross Unrealized Losses 238 53
Fair Value 5,704 5,500
Banks/financial institutions | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 2,860 2,808
Gross Unrealized Gains 389 633
Gross Unrealized Losses 35 8
Fair Value 3,214 3,433
Other corporate    
Debt Securities, Available-for-Sale [Line Items]    
Fair Value 29,002 32,473
Other corporate | Yen-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 4,852 4,085
Gross Unrealized Gains 649 809
Gross Unrealized Losses 44 7
Fair Value 5,457 4,887
Other corporate | Dollar-denominated    
Debt Securities, Available-for-Sale [Line Items]    
Cost or Amortized Cost 23,311 25,384
Gross Unrealized Gains 1,343 2,620
Gross Unrealized Losses 1,109 418
Fair Value 23,545 27,586
Fixed maturity securities    
Debt Securities, Available-for-Sale [Line Items]    
Perpetual securities, amortized cost 1,139 1,462
Perpetual securities, fair value $ 1,140 $ 1,789
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[4] Includes perpetual securities
[5] Includes perpetual securities
v3.10.0.1
INVESTMENTS - Held-to-Maturity Debt Securities (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost $ 30,318 $ 31,430
Gross Unrealized Gains 6,470 6,651
Gross Unrealized Losses 66 9
Fair Value 36,722 38,072
Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 30,318 31,430
Gross Unrealized Gains 6,470 6,651
Gross Unrealized Losses 66 9
Fair Value 36,722 38,072
Japan government and agencies | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 21,712 21,331
Gross Unrealized Gains 5,326 5,160
Gross Unrealized Losses 0 0
Fair Value 27,038 26,491
Municipalities    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 359 357
Fair Value 469 462
Municipalities | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 359 357
Gross Unrealized Gains 110 105
Gross Unrealized Losses 0 0
Fair Value 469 462
Mortgage- and asset-backed securities    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 14 26
Fair Value 15 27
Mortgage- and asset-backed securities | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 14 26
Gross Unrealized Gains 1 1
Gross Unrealized Losses 0 0
Fair Value 15 27
Public utilities    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 2,727 3,300
Fair Value 2,973 3,698
Public utilities | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 2,727 3,300
Gross Unrealized Gains 254 398
Gross Unrealized Losses 8 0
Fair Value 2,973 3,698
Sovereign and supranational    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 1,551 1,523
Fair Value 1,840 1,835
Sovereign and supranational | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 1,551 1,523
Gross Unrealized Gains 289 312
Gross Unrealized Losses 0 0
Fair Value 1,840 1,835
Banks/financial institutions    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 1,445 2,206
Fair Value 1,583 2,387
Banks/financial institutions | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 1,445 2,206
Gross Unrealized Gains 158 190
Gross Unrealized Losses 20 9
Fair Value 1,583 2,387
Other corporate    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 2,510 2,687
Fair Value 2,804 3,172
Other corporate | Yen-denominated    
Schedule of Held-to-maturity Securities [Line Items]    
Securities held to maturity, fixed maturities, amortized cost 2,510 2,687
Gross Unrealized Gains 332 485
Gross Unrealized Losses 38 0
Fair Value $ 2,804 $ 3,172
v3.10.0.1
INVESTMENTS - Equity Securities (Details)
$ in Millions
Dec. 31, 2018
USD ($)
Equity Securities, FV-NI [Line Items]  
Fair Value $ 987 [1],[2],[3]
Yen-denominated  
Equity Securities, FV-NI [Line Items]  
Fair Value 641
Dollar-denominated  
Equity Securities, FV-NI [Line Items]  
Fair Value 346
Equity securities  
Equity Securities, FV-NI [Line Items]  
Perpetual securities, fair value $ 62
[1] Includes perpetual securities ($62 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
v3.10.0.1
INVESTMENTS - Equity Securities, Prior Period (Details)
$ in Millions
Dec. 31, 2017
USD ($)
Investment [Line Items]  
Equity securities, available-for-sale $ 1,023
Yen-denominated  
Investment [Line Items]  
Equity securities, available-for-sale 695
Dollar-denominated  
Investment [Line Items]  
Equity securities, available-for-sale $ 328
v3.10.0.1
INVESTMENTS - Contractual and Economic Maturities of Investments in Fixed Maturities (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Available for sale:    
Due in one year or less [1] $ 810  
Due after one year through five years [1] 8,313  
Due after five years through 10 years [1] 9,805  
Due after 10 years [1] 57,618  
Mortgage- and asset-backed securities [1] 310  
Total fixed maturity securities, available for sale, amortized cost 76,856 [1],[2] $ 75,132 [3]
Held to maturity:    
Due in one year or less 180  
Due after one year through five years 915  
Due after five years through 10 years 927  
Due after 10 years 28,282  
Mortgage- and asset-backed securities 14  
Total fixed maturity securities, held to maturity, amortized cost 30,318 31,430
Available for sale:    
Due in one year or less [1] 861  
Due after one year through five years [1] 8,312  
Due after five years through 10 years [1] 10,355  
Due after 10 years [1] 63,028  
Mortgage- and asset-backed securities [1] 339  
Total fixed maturity securities, available for sale, fair value [4],[5] 82,895 [1],[2] 84,313 [3]
Held to maturity:    
Due in one year or less 182  
Due after one year through five years 948  
Due after five years through 10 years 1,004  
Due after 10 years 34,573  
Mortgage- and asset-backed securities 15  
Total fixed maturity securities, held to maturity, fair value $ 36,722 $ 38,072
[1] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[2] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[4] Includes perpetual securities
[5] Includes perpetual securities
v3.10.0.1
INVESTMENTS - Investment Exposures Individually Exceeded 10% of Shareholders' Equity (Detail) - Japan National Government - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Summary of Investment Holdings [Line Items]    
Credit Rating [1] A+ A
Amortized Cost [1] $ 51,207 $ 48,399
Fair Value [1] $ 59,945 $ 56,532
[1] Japan Government Bonds (JGBs) or JGB-backed securities
v3.10.0.1
INVESTMENTS - Information Regarding Pretax Realized Gains and Losses From Investments (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Gain (Loss) on Securities [Line Items]      
Other-than-temporary impairment losses realized $ (81)    
Loan loss reserves (17) $ (8) $ (2)
Other gains (losses) on loans (2) 0 0
Derivative gains (losses) (224) (109) (255)
Foreign currency gains (losses) (10) (33) 185
Total realized investment gains (losses) (430) (151) (14)
Other-than-temporary impairment losses realized   (37) (85)
Loan receivables      
Gain (Loss) on Securities [Line Items]      
Total realized investment gains (losses) (19) (8) (2)
Derivatives and other      
Gain (Loss) on Securities [Line Items]      
Total realized investment gains (losses) (234) (142) (70)
Equity securities      
Gain (Loss) on Securities [Line Items]      
Total realized investment gains (losses) [1],[2] (131) 71 [3] (35) [3]
Other-than-temporary impairment losses realized   (22) (57)
Available-for-sale securities | Fixed maturity securities      
Gain (Loss) on Securities [Line Items]      
Gross gains from sales 101 51 177
Gross losses from sales (156) (68) (62)
Foreign currency gains (losses) on sales and redemptions 73 (48) 4
Other-than-temporary impairment losses realized (64) (7) (26)
Total realized investment gains (losses) $ (46) $ (72) $ 93
[1] Includes perpetual securities
[2] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[3] Includes impairments of $22 in 2017 and $57 in 2016
v3.10.0.1
INVESTMENTS - Information Regarding Changes in Unrealized Gains and Losses from Investments (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Changes in unrealized gains (losses):      
Changes in unrealized gains (losses) $ (3,142) $ 1,728 $ 2,799
Fixed maturity securities | Available-for-sale securities      
Changes in unrealized gains (losses):      
Changes in unrealized gains (losses) [1] (3,142) 1,657 2,711
Equity securities      
Changes in unrealized gains (losses):      
Changes in unrealized gains (losses) [2] $ 0 $ 71 $ 88
[1] Includes perpetual securities
[2] See Note 1 and Note 11 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance and the cumulative effect of the change in accounting principle related to financial instruments effective January 1, 2018.
v3.10.0.1
INVESTMENTS - Net Effect on Shareholders' Equity of Unrealized Gains and Losses from Investment Securities (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Investments [Abstract]    
Unrealized gains (losses) on securities available for sale $ 6,039 $ 9,358
Deferred income taxes (1,805) (3,394)
Shareholders' equity, unrealized gains (losses) on investment securities [1] $ 4,234 $ 5,964
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
v3.10.0.1
INVESTMENTS - Fair Value and Gross Unrealized Losses for Securities That Have Been in Continuous Unrealized Loss Position (Detail) - Fixed maturity securities - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] $ 24,484 $ 16,685
Total Unrealized Losses [1] 1,760 813
Less Than 12 months Fair Value [1] 16,389 5,776
Less Than 12 months Unrealized Losses [1] 985 77
12 months or longer Fair Value [1] 8,095 10,909
12 months or longer Unrealized Losses [1] 775 736
Dollar-denominated | U.S. government and agencies    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 67 74
Total Unrealized Losses [1] 1 1
Less Than 12 months Fair Value [1] 67 74
Less Than 12 months Unrealized Losses [1] 1 1
12 months or longer Fair Value [1] 0 0
12 months or longer Unrealized Losses [1] 0 0
Dollar-denominated | Municipalities    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 515  
Total Unrealized Losses [1] 8  
Less Than 12 months Fair Value [1] 515  
Less Than 12 months Unrealized Losses [1] 8  
12 months or longer Fair Value [1] 0  
12 months or longer Unrealized Losses [1] 0  
Dollar-denominated | Mortgage- and asset-backed securities    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 74  
Total Unrealized Losses [1] 1  
Less Than 12 months Fair Value [1] 74  
Less Than 12 months Unrealized Losses [1] 1  
12 months or longer Fair Value [1] 0  
12 months or longer Unrealized Losses [1] 0  
Dollar-denominated | Public utilities    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 1,585 785
Total Unrealized Losses [1] 105 27
Less Than 12 months Fair Value [1] 892 221
Less Than 12 months Unrealized Losses [1] 48 3
12 months or longer Fair Value [1] 693 564
12 months or longer Unrealized Losses [1] 57 24
Dollar-denominated | Banks/financial institutions    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 625 362
Total Unrealized Losses [1] 35 8
Less Than 12 months Fair Value [1] 340 316
Less Than 12 months Unrealized Losses [1] 19 5
12 months or longer Fair Value [1] 285 46
12 months or longer Unrealized Losses [1] 16 3
Dollar-denominated | Other corporate    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 12,899 7,741
Total Unrealized Losses [1] 1,109 418
Less Than 12 months Fair Value [1] 5,782 2,839
Less Than 12 months Unrealized Losses [1] 407 50
12 months or longer Fair Value [1] 7,117 4,902
12 months or longer Unrealized Losses [1] 702 368
Yen-denominated | Japan government and agencies    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 3,604 5,255
Total Unrealized Losses [1] 140 271
Less Than 12 months Fair Value [1] 3,604 1,264
Less Than 12 months Unrealized Losses [1] 140 9
12 months or longer Fair Value [1] 0 3,991
12 months or longer Unrealized Losses [1] 0 262
Yen-denominated | Municipalities    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 148 129
Total Unrealized Losses [1] 9 12
Less Than 12 months Fair Value [1] 148 10
Less Than 12 months Unrealized Losses [1] 9 0
12 months or longer Fair Value [1] 0 119
12 months or longer Unrealized Losses [1] 0 12
Yen-denominated | Public utilities    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 604 83
Total Unrealized Losses [1] 12 6
Less Than 12 months Fair Value [1] 604 0
Less Than 12 months Unrealized Losses [1] 12 0
12 months or longer Fair Value [1] 0 83
12 months or longer Unrealized Losses [1] 0 6
Yen-denominated | Sovereign and supranational    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1]   309
Total Unrealized Losses [1]   1
Less Than 12 months Fair Value [1]   309
Less Than 12 months Unrealized Losses [1]   1
12 months or longer Fair Value [1]   0
12 months or longer Unrealized Losses [1]   0
Yen-denominated | Banks/financial institutions    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 3,057 1,507
Total Unrealized Losses [1] 258 62
Less Than 12 months Fair Value [1] 3,057 394
Less Than 12 months Unrealized Losses [1] 258 4
12 months or longer Fair Value [1] 0 1,113
12 months or longer Unrealized Losses [1] 0 58
Yen-denominated | Other corporate    
Investments, Unrealized Loss Position [Line Items]    
Total Fair Value [1] 1,306 440
Total Unrealized Losses [1] 82 7
Less Than 12 months Fair Value [1] 1,306 349
Less Than 12 months Unrealized Losses [1] 82 4
12 months or longer Fair Value [1] 0 91
12 months or longer Unrealized Losses [1] $ 0 $ 3
[1] Includes perpetual securities
v3.10.0.1
INVESTMENTS - Other Investments (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Investment [Line Items]    
Other investments [1] $ 7,706 $ 3,402
Transitional real estate loans    
Investment [Line Items]    
Other investments 4,377 1,235
Commercial mortgage loans    
Investment [Line Items]    
Other investments 1,064 908
Middle market loans    
Investment [Line Items]    
Other investments 1,478 859
Policy loans    
Investment [Line Items]    
Other investments 232 210
Short-term investments    
Investment [Line Items]    
Other investments 152 57
Other Investments    
Investment [Line Items]    
Other investments $ 403 $ 133
[1] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
v3.10.0.1
INVESTMENTS - Investments in Consolidated Variable Interest Entities (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Variable Interest Entity [Line Items]    
Available for sale, fixed maturity securities, amortized cost $ 76,856 [1],[2] $ 75,132 [3]
Available for sale, fixed maturity securities [4],[5] 82,895 [1],[2] 84,313 [3]
Equity securities [4],[5],[6] 987  
Available for sale securities, equity securities   1,023
Other investments [7] 7,706 3,402
Asset derivatives 417 331
Assets, fair value 88,788 89,215
Liability derivatives 387 474
Liabilities 116,944 112,619
Liabilities, fair value 387 474
Variable Interest Entity, Consolidated    
Variable Interest Entity [Line Items]    
Available for sale, fixed maturity securities, amortized cost [8] 3,849 4,538
Available for sale, fixed maturity securities [8],[9] 4,466 5,509
Equity securities, FV-NI, cost 160  
Equity securities 160  
Available for sale equity securities, amortized cost basis   606
Available for sale securities, equity securities   753
Other investments [10] 5,856 2,341
Other investments, fair value [10] 5,834 2,328
Asset derivatives, amortized cost [11] 182 151
Asset derivatives [11] 182 151
Assets, amortized cost 10,047 7,636
Assets, fair value 10,642 8,741
Liability derivatives, amortized cost [11] 102 128
Liability derivatives [11] 102 128
Liabilities 102 128
Liabilities, fair value $ 102 $ 128
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[4] Includes perpetual securities
[5] Includes perpetual securities
[6] Includes perpetual securities ($62 at fair value)
[7] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
[8] Includes perpetual securities
[9] Includes perpetual securities, see Notes 1 and 3 of the Notes to the Consolidated Financial Statements
[10] Consists of TREs, CMLs, MMLs, and alternative investments in limited partnerships
[11] Consists entirely of derivatives
v3.10.0.1
INVESTMENTS - Investments in Variable Interest Entities Not Consolidated (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Variable Interest Entity [Line Items]    
Available for sale, fixed maturity securities, amortized cost $ 76,856 [1],[2] $ 75,132 [3]
Available for sale, fixed maturity securities [4],[5] 82,895 [1],[2] 84,313 [3]
Securities held to maturity, fixed maturities, amortized cost 30,318 31,430
Held to maturity, fixed maturity securities, fair value 36,722 38,072
Other investments [6] 7,706 3,402
Assets, fair value 88,788 89,215
Variable Interest Entity, Not Consolidated    
Variable Interest Entity [Line Items]    
Available for sale, fixed maturity securities, amortized cost [7] 4,575 5,004
Available for sale, fixed maturity securities [7] 4,982 5,724
Securities held to maturity, fixed maturities, amortized cost 2,007 2,549
Held to maturity, fixed maturity securities, fair value 2,254 2,929
Other investments 49 55
Other investments, fair value 49 55
Assets, amortized cost 6,631 7,608
Assets, fair value $ 7,285 $ 8,708
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[4] Includes perpetual securities
[5] Includes perpetual securities
[6] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
[7] Includes perpetual securities
v3.10.0.1
INVESTMENTS - Securities Lending Transactions Accounted for as Secured Borrowings (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred $ 2,242 $ 606
Gross amount of recognized liabilities for securities lending 1,052 606
Amounts related to agreements not included in offsetting disclosure in Note 4 1,190 0
Japan government and agencies    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 1,577 49
Municipalities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 5  
Public utilities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 27 73
Banks/financial institutions    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 74 54
Other corporate    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 549 415
Equity securities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 10 15
Maturity Overnight and Continuous    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 665 557
Maturity Overnight and Continuous | Japan government and agencies    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 0 0
Maturity Overnight and Continuous | Municipalities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 5  
Maturity Overnight and Continuous | Public utilities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 27 73
Maturity Overnight and Continuous | Banks/financial institutions    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 74 54
Maturity Overnight and Continuous | Other corporate    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 549 415
Maturity Overnight and Continuous | Equity securities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred [1] 10 15
Maturity up to 30 Days    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 387 49
Maturity up to 30 Days | Japan government and agencies    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 387 49
Maturity up to 30 Days | Municipalities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0  
Maturity up to 30 Days | Public utilities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0 0
Maturity up to 30 Days | Banks/financial institutions    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0 0
Maturity up to 30 Days | Other corporate    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0 0
Maturity up to 30 Days | Equity securities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0 $ 0
Maturity Greater than 90 Days    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 1,190  
Maturity Greater than 90 Days | Japan government and agencies    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 1,190  
Maturity Greater than 90 Days | Municipalities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0  
Maturity Greater than 90 Days | Public utilities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0  
Maturity Greater than 90 Days | Banks/financial institutions    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0  
Maturity Greater than 90 Days | Other corporate    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred 0  
Maturity Greater than 90 Days | Equity securities    
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]    
Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred $ 0  
[1] These securities are pledged as collateral under the Company's U.S. securities lending program and can be called at its discretion; therefore, they are classified as Overnight and Continuous.
v3.10.0.1
INVESTMENTS - Additional Information (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2018
USD ($)
investment
Dec. 31, 2017
USD ($)
investment
Dec. 31, 2016
investment
Schedule of Investments [Line Items]      
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, number of investments | investment 0 3 0
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, amortized cost   $ 773  
Reclassified investments from the held-to-maturity portfolio to the available-for-sale portfolio, aggregate unrealized gain (loss)   47  
Equity securities, FV-NI, unrealized gain (loss) $ (124)    
Allowance for loan loss 27 11  
Transitional real estate loan commitments 605    
Commercial mortgage loan commitments 25    
Middle market loan program unfunded amount 56 $ 109  
Middle market loan commitments 521    
Limited partnerships investment commitments $ 916    
Percentage that the lending policy requires that the fair value of the securities and/or unrestricted cash received as collateral be of the fair value of the loaned securities 102.00%    
Percentage that the lending policy requires that the fair value of the unrestricted cash received as collateral be of the fair value of the loaned securities 100.00%    
Fair value of debt securities on deposit with regulatory authorities in the United States and Japan $ 19    
v3.10.0.1
DERIVATIVE INSTRUMENTS - Additional Information (Detail)
$ in Millions
 12 Months Ended
Dec. 31, 2018
USD ($)
yr
counterparties
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Mar. 31, 2015
USD ($)
Nov. 30, 2014
USD ($)
Jun. 30, 2013
USD ($)
Feb. 29, 2012
USD ($)
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Cash flow hedging activity, maximum time period l yr | yr 7            
Number of counterparties | counterparties 16            
Number of counterparties that comprise majority of aggregate notional amount of swaps | counterparties 3            
Percentage of notional amount of swaps from certain number of counterparties 52.00%            
Derivative, Net Liability Position, Aggregate Fair Value $ 139 $ 264          
Additional Collateral, Aggregate Fair Value 34            
Cash flow hedges              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net (2)            
Net investment hedge              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Net investment hedge gain loss reclassified to earnings net 0 $ 0 $ 0        
4.00% senior notes due February 2022              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Debt instrument, principal amount 350           $ 350
3.625% senior notes due June 2023              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Debt instrument, principal amount 700         $ 700  
3.625% senior notes due November 2024              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Debt instrument, principal amount 750       $ 750    
3.25% senior notes due March 2025              
Derivative Instruments and Hedging Activities Disclosure [Line Items]              
Debt instrument, principal amount $ 450     $ 450      
v3.10.0.1
DERIVATIVE INSTRUMENTS - Summary of Balance Sheet Classification of Derivative Fair Value Amounts, as well as Gross Asset and Liability Fair Value Amounts (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount $ 38,355 $ 25,751
Derivative asset, fair value, gross asset including not subject to master netting arrangement 417 331
Derivative liability, fair value, gross liability including not subject to master netting arrangement (387) (474)
Asset derivatives fair value 234 180
Liability derivatives fair value (285) (346)
Other assets    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 23,713 10,948
Asset derivatives fair value 417 331
Liability derivatives fair value 0 0
Other liabilities    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 14,642 14,803
Asset derivatives fair value 0 0
Liability derivatives fair value (387) (474)
Cash flow hedges    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 75 75
Asset derivatives fair value 1 0
Liability derivatives fair value (4) (8)
Cash flow hedges | Foreign currency swaps    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 75 75
Asset derivatives fair value 1 0
Liability derivatives fair value (4) (8)
Fair value hedges    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 11,656 15,310
Asset derivatives fair value 3 2
Liability derivatives fair value (36) (223)
Fair value hedges | Foreign currency forwards    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 2,086 7,640
Asset derivatives fair value 0 2
Liability derivatives fair value (34) (221)
Fair value hedges | Foreign currency options    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 9,070 7,670
Asset derivatives fair value 3 0
Liability derivatives fair value (1) (2)
Fair value hedges | Interest rate swaptions    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 500 0
Asset derivatives fair value 0 0
Liability derivatives fair value (1) 0
Net investment hedge    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 0 439
Asset derivatives fair value 0 12
Liability derivatives fair value 0 (1)
Net investment hedge | Foreign currency forwards    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 0 5
Asset derivatives fair value 0 0
Liability derivatives fair value 0 0
Net investment hedge | Foreign currency options    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 0 434
Asset derivatives fair value 0 12
Liability derivatives fair value 0 (1)
Non-qualifying strategies    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 26,624 9,927
Asset derivatives fair value 413 317
Liability derivatives fair value (347) (242)
Non-qualifying strategies | Foreign currency swaps    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 5,387 5,386
Asset derivatives fair value 284 296
Liability derivatives fair value (230) (189)
Non-qualifying strategies | Foreign currency forwards    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 16,057 3,683
Asset derivatives fair value 126 20
Liability derivatives fair value (117) (53)
Non-qualifying strategies | Foreign currency options    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 430 770
Asset derivatives fair value 0 0
Liability derivatives fair value 0 0
Non-qualifying strategies | Credit default swaps    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 0 88
Asset derivatives fair value 0 1
Liability derivatives fair value 0 0
Non-qualifying strategies | Interest rate swaps    
Derivatives, Fair Value [Line Items]    
Net Derivatives Notional Amount 4,750 0
Asset derivatives fair value 3 0
Liability derivatives fair value $ 0 $ 0
v3.10.0.1
DERIVATIVE INSTRUMENTS - Gains (Losses) Recognized on Fair Value Hedging Relationships (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]      
Total gains (losses) recognized for derivatives $ 129 $ 119 $ 112
Gains (losses) on derivatives excluded from effectiveness testing [1] (101) (192) (356)
Gain (losses) on derivatives included in effectiveness testing [2] 230 311 468
Gains (losses) recognized for hedged items [2] (242) (288) (496)
Net realized gains (losses) recognized for fair value hedge (12) 23 (28)
Fixed maturity securities | Foreign currency forwards      
Derivative Instruments, Gain (Loss) [Line Items]      
Total gains (losses) recognized for derivatives 126    
Gains (losses) on derivatives excluded from effectiveness testing [1] (104)    
Gain (losses) on derivatives included in effectiveness testing [2] 230    
Gains (losses) recognized for hedged items [2] (242)    
Net realized gains (losses) recognized for fair value hedge (12)    
Fixed maturity securities | Foreign currency options      
Derivative Instruments, Gain (Loss) [Line Items]      
Total gains (losses) recognized for derivatives 4 21 (95)
Gains (losses) on derivatives excluded from effectiveness testing [1] 4 10 (18)
Gain (losses) on derivatives included in effectiveness testing [2] 0 11 (77)
Gains (losses) recognized for hedged items [2] 0 (10) 70
Net realized gains (losses) recognized for fair value hedge 0 1 (7)
Fixed maturity securities | Interest rate swaptions      
Derivative Instruments, Gain (Loss) [Line Items]      
Total gains (losses) recognized for derivatives (1)    
Gains (losses) on derivatives excluded from effectiveness testing [1] (1)    
Gain (losses) on derivatives included in effectiveness testing [2] 0    
Gains (losses) recognized for hedged items [2] 0    
Net realized gains (losses) recognized for fair value hedge $ 0    
Fixed maturity and equity securities | Foreign currency forwards      
Derivative Instruments, Gain (Loss) [Line Items]      
Total gains (losses) recognized for derivatives   98 207
Gains (losses) on derivatives excluded from effectiveness testing [1]   (202) (338)
Gain (losses) on derivatives included in effectiveness testing [2]   300 545
Gains (losses) recognized for hedged items [2]   (278) (566)
Net realized gains (losses) recognized for fair value hedge   $ 22 $ (21)
[1] Gains (losses) excluded from effectiveness testing includes the forward point on foreign currency forwards and time value change on foreign currency options which are reported in the consolidated statement of earnings as realized investment gains (losses). It also includes the change in the fair value of the interest rate swaptions related to the time value of the swaptions which is recognized as a component of other comprehensive income (loss).
[2] Gains and losses on foreign currency forwards and options and related hedged items are reported in the consolidated statement of earnings as realized investment gains (losses). For interest rate swaptions and related hedged items, gains and losses included in the hedge assessment are reported within net investment income. For the year ended December 31, 2018, those gains and losses on interest rate swaptions and related hedged items were immaterial.
v3.10.0.1
DERIVATIVE INSTRUMENTS - Schedule of Interest Rate Fair Value Hedges Hedged Items (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives $ 38,355 $ 25,751
Fair value hedges    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives 11,656 15,310
Interest rate swaptions | Fair value hedges    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives 500 $ 0
Fixed maturity securities | Interest rate swaptions    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Carrying Amount of Hedged Assets/ (Liabilities) [1] 6,593  
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of Hedged Assets/ (Liabilities) $ 294  
[1] The balance includes $294 million of hedging adjustment on discontinued hedging relationships.
v3.10.0.1
DERIVATIVE INSTRUMENTS - Derivatives and Hedging Instruments Gain (Loss) Summary (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]      
Unrealized foreign currency translation gains (losses) during period $ 232 $ 286 $ 283
Derivative gains (losses) (224) (109) (255)
Derivative and non-derivative hedging instruments gain (loss) recognized in other comprehensive income effective portion before tax [1] (38) (34) (42)
Cash flow hedges      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) [2] 0 0 1
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion) [1] 3 1 3
Cash flow hedges | Foreign currency swaps      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) 0 0 1
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion) [1] 3 1 3
Fair value hedges      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) (112) (169) (384)
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion) [1] (1) 0 0
Fair value hedges | Foreign currency forwards      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) [3] (116) (180) (359)
Fair value hedges | Foreign currency options      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) [3] 4 11 (25)
Fair value hedges | Interest rate swaptions      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) [3] 0 0 0
Gain (Loss) Recognized in Other Comprehensive Income on Derivative (Effective Portion) [1],[3] (1) 0 0
Net investment hedge      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) 0 0 0
Unrealized foreign currency translation gains (losses) during period [1] (40) (35) (45)
Net investment hedge | Foreign currency forwards      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) 0 0 0
Unrealized foreign currency translation gains (losses) during period [1] 0 (25) (118)
Net investment hedge | Foreign currency options      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) 0 0 0
Unrealized foreign currency translation gains (losses) during period [1] (8) 5 73
Net investment hedge | Non-derivative hedging instruments      
Derivative Instruments, Gain (Loss) [Line Items]      
Net Realized Investment Gains (Losses) Recognized in Income on Derivative (Ineffective Portion) 0 0 0
Unrealized foreign currency translation gains (losses) during period [1] (32) (15) 0
Non-qualifying strategies      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instrument, Gain (Loss) Recognized in Income, Net (112) 60 128
Non-qualifying strategies | Foreign currency swaps      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instrument, Gain (Loss) Recognized in Income, Net 20 53 117
Non-qualifying strategies | Foreign currency forwards      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instrument, Gain (Loss) Recognized in Income, Net (135) 8 9
Non-qualifying strategies | Credit default swaps      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instrument, Gain (Loss) Recognized in Income, Net 0 (1) 2
Non-qualifying strategies | Interest rate swaps      
Derivative Instruments, Gain (Loss) [Line Items]      
Derivative Instrument, Gain (Loss) Recognized in Income, Net $ 3 $ 0 $ 0
[1] Cash flow hedge items and the change in the fair value of interest rate swaptions related to the time value of the swaptions in fair value hedges are recorded as unrealized gains (losses) on derivatives and net investment hedge items are recorded in the unrealized foreign currency translation gains (losses) line in the consolidated statement of comprehensive income (loss).
[2] Impact of cash flow hedges reported as realized investment gains (losses) includes an immaterial amount of gains or losses reclassified from accumulated other comprehensive income (loss) into earnings. It also includes an immaterial amount excluded from effectiveness testing during the years ended December 31, 2018 and 2017 and $1 million during the year ended December 31, 2016.
[3] Impact shown net of effect of hedged items (see Fair Value Hedges section of this Note 4 for further detail)
v3.10.0.1
DERIVATIVE INSTRUMENTS - Fair Value and Notional Amount of Derivatives with Counterparty Credit Risk (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives $ 38,355 $ 25,751
Asset Derivatives Fair Value 417 331
Liability Derivatives Fair Value (387) (474)
AA    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives 5,399 4,708
Asset Derivatives Fair Value 63 52
Liability Derivatives Fair Value (23) (37)
A    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives 32,513 20,604
Asset Derivatives Fair Value 350 271
Liability Derivatives Fair Value (311) (370)
BBB    
Derivative Instruments and Hedging Activities Disclosures [Line Items]    
Notional Amount of Derivatives 443 439
Asset Derivatives Fair Value 4 8
Liability Derivatives Fair Value $ (53) $ (67)
v3.10.0.1
DERIVATIVE INSTRUMENTS - Offsetting of Financial Assets and Derivative Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Offsetting Assets [Line Items]    
Gross amount of recognized derivative assets $ 234 $ 180
Gross amount of liabilities offset in balance sheet 0 0
Net amount of derivative assets presented in balance sheet 234 180
Financial instruments, amounts not offset (152) (82)
Derivative, collateral, obligation to return securities (23) 0
Derivative, collateral, obligation to return cash (58) (98)
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement 1 0
Derivative asset, not subject to master netting arrangement 183 151
Derivative asset, fair value, amount offset against collateral, not subject to master netting agreement 183 151
Derivative asset, fair value, gross asset including not subject to master netting arrangement 417 331
Net amounts of derivative assets presented in balance sheet 417 331
Derivative asset, fair value, amount offset against collateral 184 151
Gross amounts of recognized financial instruments 1,446 923
Gross amounts offest in balance sheet 0 0
Net amounts of assets presented in balance sheet 1,446 923
Carrying value of financial instruments not offset in balance sheet (152) (82)
Securities collateral, not offset in balance sheet (23) 0
Cash collateral, not offset in balance sheet (1,087) (690)
Financial instruments, amount of assets offset against collateral 184 151
Over the Counter - Bilateral    
Offsetting Assets [Line Items]    
Gross amount of recognized derivative assets 231 180
Gross amount of liabilities offset in balance sheet 0 0
Net amount of derivative assets presented in balance sheet 231 180
Financial instruments, amounts not offset (152) (82)
Derivative, collateral, obligation to return securities (23) 0
Derivative, collateral, obligation to return cash (55) (98)
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement 1 0
Derivative asset, not subject to master netting arrangement 183 151
Derivative asset, fair value, amount offset against collateral, not subject to master netting agreement 183 151
Over the Counter- Cleared    
Offsetting Assets [Line Items]    
Gross amount of recognized derivative assets 3  
Gross amount of liabilities offset in balance sheet 0  
Net amount of derivative assets presented in balance sheet 3  
Financial instruments, amounts not offset 0  
Derivative, collateral, obligation to return securities 0  
Derivative, collateral, obligation to return cash (3)  
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement 0  
Securities Lending and Similar Arrangements    
Offsetting Assets [Line Items]    
Gross amounts of recognized financial instruments 1,029 592
Gross amounts offest in balance sheet 0 0
Net amounts of assets presented in balance sheet 1,029 592
Carrying value of financial instruments not offset in balance sheet 0 0
Securities collateral, not offset in balance sheet 0 0
Cash collateral, not offset in balance sheet (1,029) (592)
Financial instruments, amount of assets offset against collateral $ 0 $ 0
v3.10.0.1
DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Offsetting Liabilities [Line Items]    
Gross amount of recognized derivative liabilities $ (285) $ (346)
Gross amount of assets offset in balance sheet 0 0
Derivative liability, fair value, amount not offset against collateral (285) (346)
Financial instruments, amounts not offset 152 82
Derivative, collateral, right to reclaim securities 37 245
Derivative, collateral, right to reclaim cash 68 10
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement (28) (9)
Derivative liability, not subject to master netting arrangement (102) (128)
Derivative liability, fair value, amount offset against collateral, not subject to master netting agreement (102) (128)
Derivative liability, fair value, gross liability including not subject to master netting arrangement (387) (474)
Net amount of derivative liabilities presented in balance sheet (387) (474)
Derivative liability, fair value, amount offset against collateral (130) (137)
Gross amounts of recognized financial instruments, offsetting liabilities (1,439) (1,080)
Gross amounts offset in statement of financial position, offsetting liabilities 0 0
Net amounts of financial instruments presented in balance sheet, offsetting liabilities (1,439) (1,080)
Carrying value of financial instruments, liabilities not offset in balance sheet 1,181 674
Securities collateral, liabilities not offset in balance sheet 37 245
Cash collateral, liabilities not offset in balance sheet 68 10
Financial instruments, amount of liabilities offset against collateral (153) (151)
Over the Counter - Bilateral    
Offsetting Liabilities [Line Items]    
Gross amount of recognized derivative liabilities (285) (346)
Gross amount of assets offset in balance sheet 0 0
Derivative liability, fair value, amount not offset against collateral (285) (346)
Financial instruments, amounts not offset 152 82
Derivative, collateral, right to reclaim securities 37 245
Derivative, collateral, right to reclaim cash 68 10
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement (28) (9)
Derivative liability, not subject to master netting arrangement (102) (128)
Derivative liability, fair value, amount offset against collateral, not subject to master netting agreement (102) (128)
Securities Lending and Similar Arrangements    
Offsetting Liabilities [Line Items]    
Gross amounts of recognized financial instruments, offsetting liabilities (1,052) (606)
Gross amounts offset in statement of financial position, offsetting liabilities 0 0
Net amounts of financial instruments presented in balance sheet, offsetting liabilities (1,052) (606)
Carrying value of financial instruments, liabilities not offset in balance sheet 1,029 592
Securities collateral, liabilities not offset in balance sheet 0 0
Cash collateral, liabilities not offset in balance sheet 0 0
Financial instruments, amount of liabilities offset against collateral $ (23) $ (14)
v3.10.0.1
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Assets:    
Available for sale, fixed maturity securities [2],[3] $ 82,895 [1],[4] $ 84,313 [5]
Equity securities [2],[3],[6] 987  
Equity securities, available-for-sale   1,023
Other investments 152 57
Cash and cash equivalents 4,337 3,491
Asset derivatives 417 331
Total assets 88,788 89,215
Liabilities:    
Liability derivatives 387 474
Total liabilities 387 474
Foreign currency swaps    
Assets:    
Asset derivatives 285 296
Liabilities:    
Liability derivatives 234 197
Foreign currency forwards    
Assets:    
Asset derivatives 126 22
Liabilities:    
Liability derivatives 151 274
Foreign currency options    
Assets:    
Asset derivatives 3 12
Liabilities:    
Liability derivatives 1 3
Interest rate swaptions    
Liabilities:    
Liability derivatives 1  
Interest rate swaps    
Assets:    
Asset derivatives 3  
Credit default swaps    
Assets:    
Asset derivatives   1
Government and agencies    
Assets:    
Available for sale, fixed maturity securities 34,342 31,230
Municipalities    
Assets:    
Available for sale, fixed maturity securities 1,863 1,370
Mortgage- and asset-backed securities    
Assets:    
Available for sale, fixed maturity securities 339 444
Public utilities    
Assets:    
Available for sale, fixed maturity securities 7,171 7,954
Sovereign and supranational    
Assets:    
Available for sale, fixed maturity securities 1,260 1,909
Banks/financial institutions    
Assets:    
Available for sale, fixed maturity securities 8,918 8,933
Other corporate    
Assets:    
Available for sale, fixed maturity securities 29,002 32,473
Level 1    
Assets:    
Available for sale, fixed maturity securities 32,993 30,109
Equity securities 874  
Equity securities, available-for-sale   1,001
Other investments 152 57
Cash and cash equivalents 4,337 3,491
Asset derivatives 0 0
Total assets 38,356 34,658
Liabilities:    
Total liabilities 0 0
Level 1 | Foreign currency swaps    
Assets:    
Asset derivatives 0 0
Liabilities:    
Liability derivatives 0 0
Level 1 | Foreign currency forwards    
Assets:    
Asset derivatives 0 0
Liabilities:    
Liability derivatives 0 0
Level 1 | Foreign currency options    
Assets:    
Asset derivatives 0 0
Liabilities:    
Liability derivatives 0 0
Level 1 | Interest rate swaptions    
Liabilities:    
Liability derivatives 0  
Level 1 | Interest rate swaps    
Assets:    
Asset derivatives 0  
Level 1 | Credit default swaps    
Assets:    
Asset derivatives   0
Level 1 | Government and agencies    
Assets:    
Available for sale, fixed maturity securities 32,993 30,109
Level 1 | Municipalities    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 1 | Mortgage- and asset-backed securities    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 1 | Public utilities    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 1 | Sovereign and supranational    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 1 | Banks/financial institutions    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 1 | Other corporate    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 2    
Assets:    
Available for sale, fixed maturity securities 49,380 53,790
Equity securities 67  
Equity securities, available-for-sale   6
Other investments 0 0
Cash and cash equivalents 0 0
Asset derivatives 235 180
Total assets 49,682 53,976
Liabilities:    
Total liabilities 285 346
Level 2 | Foreign currency swaps    
Assets:    
Asset derivatives 103 146
Liabilities:    
Liability derivatives 132 69
Level 2 | Foreign currency forwards    
Assets:    
Asset derivatives 126 22
Liabilities:    
Liability derivatives 151 274
Level 2 | Foreign currency options    
Assets:    
Asset derivatives 3 12
Liabilities:    
Liability derivatives 1 3
Level 2 | Interest rate swaptions    
Liabilities:    
Liability derivatives 1  
Level 2 | Interest rate swaps    
Assets:    
Asset derivatives 3  
Level 2 | Credit default swaps    
Assets:    
Asset derivatives   0
Level 2 | Government and agencies    
Assets:    
Available for sale, fixed maturity securities 1,349 1,121
Level 2 | Municipalities    
Assets:    
Available for sale, fixed maturity securities 1,863 1,370
Level 2 | Mortgage- and asset-backed securities    
Assets:    
Available for sale, fixed maturity securities 162 269
Level 2 | Public utilities    
Assets:    
Available for sale, fixed maturity securities 7,062 7,886
Level 2 | Sovereign and supranational    
Assets:    
Available for sale, fixed maturity securities 1,260 1,909
Level 2 | Banks/financial institutions    
Assets:    
Available for sale, fixed maturity securities 8,895 8,908
Level 2 | Other corporate    
Assets:    
Available for sale, fixed maturity securities 28,789 32,327
Level 3    
Assets:    
Available for sale, fixed maturity securities 522 414
Equity securities 46  
Equity securities, available-for-sale   16
Other investments 0 0
Cash and cash equivalents 0 0
Asset derivatives 182 151
Total assets 750 581
Liabilities:    
Total liabilities 102 128
Level 3 | Foreign currency swaps    
Assets:    
Asset derivatives 182 150
Liabilities:    
Liability derivatives 102 128
Level 3 | Foreign currency forwards    
Assets:    
Asset derivatives 0 0
Liabilities:    
Liability derivatives 0 0
Level 3 | Foreign currency options    
Assets:    
Asset derivatives 0 0
Liabilities:    
Liability derivatives 0 0
Level 3 | Interest rate swaptions    
Liabilities:    
Liability derivatives 0  
Level 3 | Interest rate swaps    
Assets:    
Asset derivatives 0  
Level 3 | Credit default swaps    
Assets:    
Asset derivatives   1
Level 3 | Government and agencies    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 3 | Municipalities    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 3 | Mortgage- and asset-backed securities    
Assets:    
Available for sale, fixed maturity securities 177 175
Level 3 | Public utilities    
Assets:    
Available for sale, fixed maturity securities 109 68
Level 3 | Sovereign and supranational    
Assets:    
Available for sale, fixed maturity securities 0 0
Level 3 | Banks/financial institutions    
Assets:    
Available for sale, fixed maturity securities 23 25
Level 3 | Other corporate    
Assets:    
Available for sale, fixed maturity securities $ 213 $ 146
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
[4] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[5] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[6] Includes perpetual securities ($62 at fair value)
v3.10.0.1
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Carried at Cost or Amortized Cost (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other investments [1] $ 7,706 $ 3,402
Assets:    
Securities held to maturity, fixed maturities, amortized cost 30,318 31,430
Held to maturity, fixed maturity securities, fair value 36,722 38,072
Other investments, carried at amortized cost 6,945 [2] 3,017 [3]
Other investments, carried at amortized cost, fair value 6,919 [2] 3,002 [3]
Total financial instruments, assets, not carried at fair value 37,263 34,447
Assets, fair value disclosure, financial instruments, carried at cost 43,641 41,074
Liabilities:    
Other policyholders' funds 7,146 6,939
Other policyholders' funds fair value disclosure 7,067 6,841
Notes payable 5,765 5,267
Notes payable, fair value disclosure 5,876 5,553
Total financial instrument liabilities not carried at fair value 12,911 12,206
Liabilities fair value disclosure financial instruments carried at cost 12,943 12,394
Government and agencies    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 21,712 21,331
Held to maturity, fixed maturity securities, fair value 27,038 26,491
Municipalities    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 359 357
Held to maturity, fixed maturity securities, fair value 469 462
Mortgage- and asset-backed securities    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 14 26
Held to maturity, fixed maturity securities, fair value 15 27
Public utilities    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 2,727 3,300
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Sovereign and supranational    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 1,551 1,523
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Banks/financial institutions    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 1,445 2,206
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Other corporate    
Assets:    
Securities held to maturity, fixed maturities, amortized cost 2,510 2,687
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Policy loans    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other investments 232 210
Equity method investments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Other investments 377 118
Level 1    
Assets:    
Held to maturity, fixed maturity securities, fair value 27,030 26,491
Other investments, carried at amortized cost, fair value 0 [2] 0 [3]
Assets, fair value disclosure, financial instruments, carried at cost 27,030 26,491
Liabilities:    
Other policyholders' funds fair value disclosure 0 0
Notes payable, fair value disclosure 0 0
Liabilities fair value disclosure financial instruments carried at cost 0 0
Level 1 | Government and agencies    
Assets:    
Held to maturity, fixed maturity securities, fair value 27,030 26,491
Level 1 | Municipalities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 1 | Mortgage- and asset-backed securities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 1 | Public utilities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 1 | Sovereign and supranational    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 1 | Banks/financial institutions    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 1 | Other corporate    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 2    
Assets:    
Held to maturity, fixed maturity securities, fair value 9,677 11,562
Other investments, carried at amortized cost, fair value 26 [2] 15 [3]
Assets, fair value disclosure, financial instruments, carried at cost 9,703 11,577
Liabilities:    
Other policyholders' funds fair value disclosure 0 0
Notes payable, fair value disclosure 5,606 5,288
Liabilities fair value disclosure financial instruments carried at cost 5,606 5,288
Level 2 | Government and agencies    
Assets:    
Held to maturity, fixed maturity securities, fair value 8 0
Level 2 | Municipalities    
Assets:    
Held to maturity, fixed maturity securities, fair value 469 462
Level 2 | Mortgage- and asset-backed securities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 8
Level 2 | Public utilities    
Assets:    
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Level 2 | Sovereign and supranational    
Assets:    
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Level 2 | Banks/financial institutions    
Assets:    
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Level 2 | Other corporate    
Assets:    
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Level 3    
Assets:    
Held to maturity, fixed maturity securities, fair value 15 19
Other investments, carried at amortized cost, fair value 6,893 [2] 2,987 [3]
Assets, fair value disclosure, financial instruments, carried at cost 6,908 3,006
Liabilities:    
Other policyholders' funds fair value disclosure 7,067 6,841
Notes payable, fair value disclosure 270 265
Liabilities fair value disclosure financial instruments carried at cost 7,337 7,106
Level 3 | Government and agencies    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 3 | Municipalities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 3 | Mortgage- and asset-backed securities    
Assets:    
Held to maturity, fixed maturity securities, fair value 15 19
Level 3 | Public utilities    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 3 | Sovereign and supranational    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 3 | Banks/financial institutions    
Assets:    
Held to maturity, fixed maturity securities, fair value 0 0
Level 3 | Other corporate    
Assets:    
Held to maturity, fixed maturity securities, fair value $ 0 $ 0
[1] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
[2] Excludes policy loans of $232 and equity method investments of $377, at carrying value
[3] Excludes policy loans of $210 and equity method investments of $118, at carrying value
v3.10.0.1
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Fair Value (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities [2],[3] $ 82,895 [1],[4] $ 84,313 [5]
Equity securities [2],[3],[6] 987  
Equity securities, available-for-sale   1,023
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 32,993 30,109
Equity securities 874  
Equity securities, available-for-sale   1,001
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 49,380 53,790
Equity securities 67  
Equity securities, available-for-sale   6
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 522 414
Equity securities 46  
Equity securities, available-for-sale   16
Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 941  
Equity securities, available-for-sale   1,007
Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 874  
Equity securities, available-for-sale   1,001
Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 67  
Equity securities, available-for-sale   6
Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 0  
Equity securities, available-for-sale   0
Net asset value valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 46  
Equity securities, available-for-sale   16
Net asset value valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 0  
Equity securities, available-for-sale   0
Net asset value valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 0  
Equity securities, available-for-sale   0
Net asset value valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Equity securities 46  
Equity securities, available-for-sale   16
Government and agencies    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 34,342 31,230
Government and agencies | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 32,993 30,109
Government and agencies | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,349 1,121
Government and agencies | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Government and agencies | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 34,342 31,230
Government and agencies | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 32,993 30,109
Government and agencies | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,349 1,121
Government and agencies | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Municipalities    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,863 1,370
Municipalities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Municipalities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,863 1,370
Municipalities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Municipalities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,863 1,370
Municipalities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Municipalities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,863 1,370
Municipalities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 339 444
Mortgage- and asset-backed securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 162 269
Mortgage- and asset-backed securities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 177 175
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 162 269
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 162 269
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities | Consensus pricing valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 177 175
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 177 175
Public utilities    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 7,171 7,954
Public utilities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Public utilities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 7,062 7,886
Public utilities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 109 68
Public utilities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 7,062 7,886
Public utilities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Public utilities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 7,062 7,886
Public utilities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Public utilities | Discounted cash flow technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 109 68
Public utilities | Discounted cash flow technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Public utilities | Discounted cash flow technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Public utilities | Discounted cash flow technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 109 68
Sovereign and supranational    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,260 1,909
Sovereign and supranational | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Sovereign and supranational | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,260 1,909
Sovereign and supranational | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Sovereign and supranational | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,260 1,807
Sovereign and supranational | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Sovereign and supranational | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 1,260 1,807
Sovereign and supranational | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Sovereign and supranational | Consensus pricing valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities   102
Sovereign and supranational | Consensus pricing valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities   0
Sovereign and supranational | Consensus pricing valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities   102
Sovereign and supranational | Consensus pricing valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities   0
Banks/financial institutions    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 8,918 8,933
Banks/financial institutions | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Banks/financial institutions | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 8,895 8,908
Banks/financial institutions | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 23 25
Banks/financial institutions | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 8,895 8,908
Banks/financial institutions | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Banks/financial institutions | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 8,895 8,908
Banks/financial institutions | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Banks/financial institutions | Consensus pricing valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 23 25
Banks/financial institutions | Consensus pricing valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Banks/financial institutions | Consensus pricing valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Banks/financial institutions | Consensus pricing valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 23 25
Other corporate    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 29,002 32,473
Other corporate | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Other corporate | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 28,789 32,327
Other corporate | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 213 146
Other corporate | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 28,789 32,327
Other corporate | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Other corporate | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 28,789 32,327
Other corporate | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Other corporate | Discounted cash flow technique    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 213 146
Other corporate | Discounted cash flow technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Other corporate | Discounted cash flow technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities 0 0
Other corporate | Discounted cash flow technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]    
Available for sale, fixed maturity securities $ 213 $ 146
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
[4] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[5] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[6] Includes perpetual securities ($62 at fair value)
v3.10.0.1
FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Amortized Cost (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value $ 36,722 $ 38,072
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 27,030 26,491
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 9,677 11,562
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 15 19
Government and agencies    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 27,038 26,491
Government and agencies | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 27,030 26,491
Government and agencies | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 8 0
Government and agencies | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Government and agencies | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 27,038 26,491
Government and agencies | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 27,030 26,491
Government and agencies | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 8 0
Government and agencies | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Municipalities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 469 462
Municipalities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Municipalities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 469 462
Municipalities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Municipalities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 469 462
Municipalities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Municipalities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 469 462
Municipalities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Mortgage- and asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 15 27
Mortgage- and asset-backed securities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Mortgage- and asset-backed securities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 8
Mortgage- and asset-backed securities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 15 19
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value   8
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value   0
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value   8
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value   0
Mortgage- and asset-backed securities | Consensus pricing valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 15 19
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 15 19
Public utilities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Public utilities | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Public utilities | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Public utilities | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Public utilities | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Public utilities | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Public utilities | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,973 3,698
Public utilities | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Sovereign and supranational    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Sovereign and supranational | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Sovereign and supranational | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Sovereign and supranational | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Sovereign and supranational | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Sovereign and supranational | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Sovereign and supranational | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,840 1,835
Sovereign and supranational | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Banks/financial institutions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Banks/financial institutions | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Banks/financial institutions | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Banks/financial institutions | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Banks/financial institutions | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Banks/financial institutions | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Banks/financial institutions | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 1,583 2,387
Banks/financial institutions | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Other corporate    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Other corporate | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Other corporate | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Other corporate | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Other corporate | Third party pricing vendor valuation technique    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Other corporate | Third party pricing vendor valuation technique | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 0 0
Other corporate | Third party pricing vendor valuation technique | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value 2,804 3,172
Other corporate | Third party pricing vendor valuation technique | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Held to maturity, fixed maturity securities, fair value $ 0 $ 0
v3.10.0.1
FAIR VALUE MEASUREMENTS - Changes in Investments and Derivatives Carried at Fair Value Classified as Level 3 (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period $ 453 $ 223
Realized investment gains (losses) included in earnings 52 42
Unrealized gains (losses) included in other comprehensive income (loss) 6 5
Purchases 127 214
Issuances 0 0
Sales 0 (3)
Settlements (6) (26)
Transfers into Level 3 16 24
Transfers out of Level 3 0 (26)
Balance, end of period 648 453
Change in unrealized gains (losses) still held 52 42
Foreign currency swaps    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]    
Balance, beginning of period [1] 22 (21)
Realized gains (losses) included in earnings [1] 54 43
Unrealized gains (losses) included in other comprehensive income (loss) [1] 4 0
Purchases [1] 0 0
Issuances [1] 0 0
Sales [1] 0 0
Settlements [1] 0 0
Transfers into Level 3 [1] 0 0
Transfers out of Level 3 [1] 0 0
Balance, end of period [1] 80 22
Change in unrealized gains (losses) still held [1] 54 43
Credit default swaps    
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]    
Balance, beginning of period [1] 1 2
Realized gains (losses) included in earnings [1] (1) (1)
Unrealized gains (losses) included in other comprehensive income (loss) [1] 0 0
Purchases [1] 0 0
Issuances [1] 0 0
Sales [1] 0 0
Settlements [1] 0 0
Transfers into Level 3 [1] 0 0
Transfers out of Level 3 [1] 0 0
Balance, end of period [1] 0 1
Change in unrealized gains (losses) still held [1] (1) (1)
Fixed maturity securities | Mortgage- and asset-backed securities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period 175 198
Realized investment gains (losses) included in earnings 0 0
Unrealized gains (losses) included in other comprehensive income (loss) 2 3
Purchases 0 0
Issuances 0 0
Sales 0 0
Settlements 0 (26)
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Balance, end of period 177 175
Change in unrealized gains (losses) still held 0 0
Fixed maturity securities | Public utilities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period 68 16
Realized investment gains (losses) included in earnings 0 0
Unrealized gains (losses) included in other comprehensive income (loss) 1 0
Purchases 40 76
Issuances 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3 0 0
Transfers out of Level 3 0 (24) [2]
Balance, end of period 109 68
Change in unrealized gains (losses) still held 0 0
Fixed maturity securities | Banks/financial institutions    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period 25 25
Realized investment gains (losses) included in earnings 0 0
Unrealized gains (losses) included in other comprehensive income (loss) (2) 0
Purchases 0 0
Issuances 0 0
Sales 0 0
Settlements 0 0
Transfers into Level 3 0 0
Transfers out of Level 3 0 0
Balance, end of period 23 25
Change in unrealized gains (losses) still held 0 0
Fixed maturity securities | Other corporate    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period 146 0
Realized investment gains (losses) included in earnings 0 0
Unrealized gains (losses) included in other comprehensive income (loss) 1 2
Purchases 56 122
Issuances 0 0
Sales 0 (2)
Settlements (6) 0
Transfers into Level 3 16 24 [2]
Transfers out of Level 3 0 0
Balance, end of period 213 146
Change in unrealized gains (losses) still held 0 0
Equity securities    
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]    
Balance, beginning of period 16 3
Realized investment gains (losses) included in earnings (1) 0
Unrealized gains (losses) included in other comprehensive income (loss) 0 0
Purchases 31 16
Issuances 0 0
Sales 0 (1)
Settlements 0 0
Transfers into Level 3 0 0
Transfers out of Level 3 0 (2) [3]
Balance, end of period 46 16
Change in unrealized gains (losses) still held $ (1) $ 0
[1] Derivative assets and liabilities are presented net
[2] Transfer due to sector classification change
[3] Transfer due to change in accounting method
v3.10.0.1
FAIR VALUE MEASUREMENTS - Fair Value Measurement Inputs and Valuation Techniques (Details)
$ in Millions
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities [2],[3] $ 82,895 [1],[4] $ 84,313 [5]
Equity securities [2],[3],[6] 987  
Equity securities, available-for-sale   1,023
Asset derivatives 417 331
Liability derivatives 387 474
Assets, fair value 88,788 89,215
Liabilities, fair value 387 474
Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 522 414
Equity securities 46  
Equity securities, available-for-sale   16
Asset derivatives 182 151
Assets, fair value 750 581
Liabilities, fair value 102 128
Net asset value valuation technique    
Fair Value Measurement Inputs and Valuation Technique    
Equity securities 46  
Equity securities, available-for-sale   16
Net asset value valuation technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Equity securities 46  
Equity securities, available-for-sale   16
Foreign currency swaps    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives 285 296
Liability derivatives 234 197
Foreign currency swaps | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives 182 150
Liability derivatives 102 128
Foreign currency swaps | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Discounted cash flow technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives 125 80
Liability derivatives 98 120
Foreign currency swaps | Fair Value, Unobservable Input, Interest Rates (USD) and Interest Rates (JPY) | Discounted cash flow technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives 57 70
Liability derivatives $ 4 $ 8
Foreign currency swaps | Credit Spread | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input 0.0019 0.0009
Derivative liability, measurement input 0.0028 0.0013
Foreign currency swaps | Credit Spread | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input 0.0120 0.0090
Derivative liability, measurement input 0.0211 0.0157
Credit default swaps    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives   $ 1
Credit default swaps | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives   1
Credit default swaps | Fair value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Discounted cash flow technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Asset derivatives   $ 1
Credit default swaps | Credit Spread | Fair value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input   0.0025
Credit default swaps | Base Correlation | Fair value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [7]   0.4633
Credit default swaps | Base Correlation | Fair value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [7]   0.4965
Credit default swaps | Recovery Rate | Fair value, Unobservable Input, Base Correlation, CDS Spreads, Recovery Rate | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input   0.3724
Dollar-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities $ 33,995 $ 38,703
Equity securities $ 346  
Equity securities, available-for-sale   $ 328
Dollar-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [8] 0.0275 0.0240
Derivative liability, measurement input [8] 0.0275 0.0240
Dollar-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [8] 0.0284 0.0254
Derivative liability, measurement input [8] 0.0284 0.0254
Dollar-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD) and Interest Rates (JPY) | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [8] 0.0275 0.0240
Derivative liability, measurement input [8] 0.0275 0.0240
Dollar-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD) and Interest Rates (JPY) | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [8] 0.0284 0.0254
Derivative liability, measurement input [8] 0.0284 0.0254
Yen-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities $ 48,900 $ 45,610
Equity securities $ 641  
Equity securities, available-for-sale   $ 695
Yen-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [9] 0.0018 0.0026
Derivative liability, measurement input [9] 0.0018 0.0026
Yen-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD), Interest Rates (JPY), and CDS Spreads | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [9] 0.0071 0.0085
Derivative liability, measurement input [9] 0.0071 0.0085
Yen-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD) and Interest Rates (JPY) | Lower Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [9] 0.0018 0.0026
Derivative liability, measurement input [9] 0.0018 0.0026
Yen-denominated | Foreign currency swaps | Discount Rate | Fair Value, Unobservable Input, Interest Rates (USD) and Interest Rates (JPY) | Upper Limit | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Derivative asset, measurement input [9] 0.0071 0.0085
Derivative liability, measurement input [9] 0.0071 0.0085
Mortgage- and asset-backed securities    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities $ 339 $ 444
Mortgage- and asset-backed securities | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 177 175
Mortgage- and asset-backed securities | Consensus pricing valuation technique    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 177 175
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 177 175
Mortgage- and asset-backed securities | Dollar-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 162 173
Mortgage- and asset-backed securities | Yen-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 177 271
Banks/financial institutions    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 8,918 8,933
Banks/financial institutions | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 23 25
Banks/financial institutions | Consensus pricing valuation technique    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 23 25
Banks/financial institutions | Consensus pricing valuation technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 23 25
Banks/financial institutions | Dollar-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 3,214 3,433
Banks/financial institutions | Yen-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 5,704 5,500
Public utilities    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 7,171 7,954
Public utilities | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 109 68
Public utilities | Discounted cash flow technique    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 109 68
Public utilities | Discounted cash flow technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 109 68
Public utilities | Dollar-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 5,163 5,973
Public utilities | Yen-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 2,008 1,981
Other corporate    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 29,002 32,473
Other corporate | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 213 146
Other corporate | Discounted cash flow technique    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 213 146
Other corporate | Discounted cash flow technique | Level 3    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 213 146
Other corporate | Dollar-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities 23,545 27,586
Other corporate | Yen-denominated    
Fair Value Measurement Inputs and Valuation Technique    
Available for sale, fixed maturity securities $ 5,457 $ 4,887
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
[4] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[5] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[6] Includes perpetual securities ($62 at fair value)
[7] Range of base correlation for the Company's bespoke tranche for attachment and detachment points corresponding to market indices
[8] Inputs derived from U.S. long-term rates to accommodate long maturity nature of the Company's swaps
[9] Inputs derived from Japan long-term rates to accommodate long maturity nature of the Company's swaps
v3.10.0.1
FAIR VALUE MEASUREMENTS - Additional Information (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Fair Value Disclosures [Abstract]    
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount $ 0 $ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount $ 0 $ 0
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Additional Information (Detail) - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Deferred Policy Acquisition Costs Disclosures [Abstract]      
Capitalization of deferred policy acquisition costs $ 1.5 $ 1.5 $ 1.4
Commissions deferred as a percentage of total acquisition costs 72.00% 72.00% 74.00%
Personnel, compensation and benefit expenses as a percentage of insurance expenses 54.00% 56.00% 53.00%
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Rollforward of Deferred Policy Acquisition Costs by Segment (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Deferred policy acquisition costs:      
Balance, beginning of year $ 9,505    
Capitalization 1,500 $ 1,500 $ 1,400
Amortization (1,245) (1,132) (1,141)
Balance, end of year 9,875 9,505  
Aflac Japan      
Deferred policy acquisition costs:      
Balance, beginning of year 6,150 5,765  
Capitalization 833 839  
Amortization (710) (630) (644)
Foreign currency translation and other 111 176  
Balance, end of year 6,384 6,150 5,765
Aflac U.S.      
Deferred policy acquisition costs:      
Balance, beginning of year 3,355 3,228  
Capitalization 669 629  
Amortization (534) (502) (497)
Foreign currency translation and other 1 0  
Balance, end of year $ 3,491 $ 3,355 $ 3,228
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Advertising Expense (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Advertising Costs [Line Items]      
Advertising expense $ 218 $ 210 $ 224
Aflac Japan      
Advertising Costs [Line Items]      
Advertising expense 108 100 100
Aflac U.S.      
Advertising Costs [Line Items]      
Advertising expense $ 110 $ 110 $ 124
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Depreciation and Other Amortization Expense (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Deferred Policy Acquisition Costs Disclosures [Abstract]      
Depreciation expense $ 48 $ 50 $ 48
Other amortization expense 1 3 6
Total depreciation and other amortization expense $ 49 $ 53 $ 54
v3.10.0.1
DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Lease and Rental Expense (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Lease and Rental Expense [Line Items]      
Lease and rental expense $ 73 $ 75 $ 75
Aflac Japan      
Lease and Rental Expense [Line Items]      
Lease and rental expense 53 52 53
Aflac U.S.      
Lease and Rental Expense [Line Items]      
Lease and rental expense 16 21 21
All other      
Lease and Rental Expense [Line Items]      
Lease and rental expense $ 4 $ 2 $ 1
v3.10.0.1
POLICY LIABILITIES - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Percentage of future policy benefits out of policy liabilities 84.00%    
Percentage of unpaid policy claims out of policy liabilities 4.00%    
Percentage of unearned premiums out of policy liabilities 5.00%    
Percentage of other poliyholders' funds out of policy liabilities 7.00%    
Percentage of advanced premiums to unearned premiums 69.00% 73.00%  
Percentage of annuities to other policyholders' fund 97.00% 98.00%  
Aflac Japan      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits 3.30% 3.40% 3.50%
Aflac U.S.      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Weighted-average interest rates reflected in the consolidated statements of earnings for future policy benefits 5.30% 5.40% 5.50%
Health insurance      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Prior year claims and claims adjustment expense $ (563) $ (518) $ (465)
Health insurance | Aflac Japan      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Prior year claims and claims adjustment expense $ (419)    
Percentage of total prior year claims and claims adjustment expense 74.00%    
Liability for unpaid claims and claims adjustment expense, foreign currency translation gain (loss) $ 14    
Prior year claims and claims adjustment expense excluding effect of foreign currency $ (404)    
Percentage of total prior year claims and claims adjustment expense excluding effect of foreign currency 72.00%    
v3.10.0.1
POLICY LIABILITIES - Liability for Future Policy Benefits (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 86,368 $ 81,857  
Aflac Japan      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.30% 3.40% 3.50%
Aflac U.S.      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 5.30% 5.40% 5.50%
Intercompany eliminations | 2015      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.00%    
Interest Rates In 20 Years 2.00%    
Liability amounts [1] $ (583) $ (609)  
Health insurance | Aflac Japan | 1992 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 11,598 10,167  
Health insurance | Aflac Japan | 1992 - 2018 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 1.00%    
Interest Rates In 20 Years 1.00%    
Health insurance | Aflac Japan | 1992 - 2018 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.50%    
Interest Rates In 20 Years 2.50%    
Health insurance | Aflac Japan | 1974 - 2013      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 1,161 1,133  
Health insurance | Aflac Japan | 1974 - 2013 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.70%    
Interest Rates In 20 Years 2.25%    
Health insurance | Aflac Japan | 1974 - 2013 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.75%    
Interest Rates In 20 Years 2.75%    
Health insurance | Aflac Japan | 1998 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.00%    
Interest Rates In 20 Years 3.00%    
Liability amounts $ 12,764 12,386  
Health insurance | Aflac Japan | 1997 - 1999      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.50%    
Interest Rates In 20 Years 3.50%    
Liability amounts $ 2,452 2,454  
Health insurance | Aflac Japan | 1994 - 1996      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 3,056 3,046  
Health insurance | Aflac Japan | 1994 - 1996 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 4.00%    
Interest Rates In 20 Years 4.00%    
Health insurance | Aflac Japan | 1994 - 1996 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 4.50%    
Interest Rates In 20 Years 4.50%    
Health insurance | Aflac Japan | 1987 - 1994      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 5.50%    
Interest Rates In 20 Years 5.50%    
Liability amounts $ 14,722 14,829  
Health insurance | Aflac Japan | 1985 - 1991      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 1,779 1,816  
Health insurance | Aflac Japan | 1985 - 1991 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 5.25%    
Interest Rates In 20 Years 5.25%    
Health insurance | Aflac Japan | 1985 - 1991 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 6.75%    
Interest Rates In 20 Years 5.50%    
Health insurance | Aflac Japan | 1978 - 1984      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 6.50%    
Interest Rates In 20 Years 5.50%    
Liability amounts $ 1,964 2,037  
Health insurance | Aflac U.S. | 2013 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 96 82  
Health insurance | Aflac U.S. | 2013 - 2018 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.00%    
Interest Rates In 20 Years 3.00%    
Health insurance | Aflac U.S. | 2013 - 2018 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.50%    
Interest Rates In 20 Years 3.50%    
Health insurance | Aflac U.S. | 2012 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.75%    
Interest Rates In 20 Years 3.75%    
Liability amounts $ 1,682 1,366  
Health insurance | Aflac U.S. | 2011      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 4.75%    
Interest Rates In 20 Years 4.75%    
Liability amounts $ 353 343  
Health insurance | Aflac U.S. | 2005 - 2010      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 5.50%    
Interest Rates In 20 Years 5.50%    
Liability amounts $ 2,946 2,944  
Health insurance | Aflac U.S. | 1988 - 2004      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 8.00%    
Interest Rates In 20 Years 6.00%    
Liability amounts $ 641 656  
Health insurance | Aflac U.S. | 1986 - 2004      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 6.00%    
Interest Rates In 20 Years 6.00%    
Liability amounts $ 1,245 1,296  
Health insurance | Aflac U.S. | 1981 - 1986      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 151 159  
Health insurance | Aflac U.S. | 1981 - 1986 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 6.50%    
Interest Rates In 20 Years 5.50%    
Health insurance | Aflac U.S. | 1981 - 1986 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 7.00%    
Interest Rates In 20 Years 6.50%    
Health insurance | Aflac U.S. | 1998 - 2004      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 7.00%    
Interest Rates In 20 Years 7.00%    
Liability amounts $ 1,311 1,310  
Health insurance | Aflac U.S. | Other years      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts 17 18  
Life insurance | Aflac Japan | 2001 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 10,296 8,850  
Life insurance | Aflac Japan | 2001 - 2018 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 1.00%    
Interest Rates In 20 Years 1.00%    
Life insurance | Aflac Japan | 2001 - 2018 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 1.85%    
Interest Rates In 20 Years 1.85%    
Life insurance | Aflac Japan | 2011 - 2017      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.00%    
Interest Rates In 20 Years 2.00%    
Liability amounts $ 5,116 4,763  
Life insurance | Aflac Japan | 2009 - 2011      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.25%    
Interest Rates In 20 Years 2.25%    
Liability amounts $ 3,867 3,393  
Life insurance | Aflac Japan | 1992 - 2006      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.19%    
Interest Rates In 20 Years 1.55%    
Liability amounts $ 5 5  
Life insurance | Aflac Japan | 2005 - 2011      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.50%    
Interest Rates In 20 Years 2.50%    
Liability amounts $ 1,769 1,642  
Life insurance | Aflac Japan | 1985 - 2006      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.70%    
Interest Rates In 20 Years 2.25%    
Liability amounts $ 2,057 2,048  
Life insurance | Aflac Japan | 2007 - 2011      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 2.75%    
Interest Rates In 20 Years 2.75%    
Liability amounts $ 1,380 1,319  
Life insurance | Aflac Japan | 1999 - 2011      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.00%    
Interest Rates In 20 Years 3.00%    
Liability amounts $ 2,249 2,189  
Life insurance | Aflac Japan | 1996 - 2009      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.50%    
Interest Rates In 20 Years 3.50%    
Liability amounts $ 678 675  
Life insurance | Aflac Japan | 1994 - 1996      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 901 908  
Life insurance | Aflac Japan | 1994 - 1996 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 4.00%    
Interest Rates In 20 Years 4.00%    
Life insurance | Aflac Japan | 1994 - 1996 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 4.50%    
Interest Rates In 20 Years 4.50%    
Life insurance | Aflac U.S. | 1956 - 2018      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Liability amounts $ 695 $ 632  
Life insurance | Aflac U.S. | 1956 - 2018 | Lower Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 3.50%    
Interest Rates In 20 Years 3.50%    
Life insurance | Aflac U.S. | 1956 - 2018 | Upper Limit      
Liability for Future Policy Benefit, by Product Segment [Line Items]      
Interest Rates Year of Issue 6.00%    
Interest Rates In 20 Years 6.00%    
[1] Elimination entry necessary due to recapture of a portion of policy liabilities ceded externally, as a result of the reinsurance retrocession transaction as described in Note 8 of the Notes to the Consolidated Financial Statements
v3.10.0.1
POLICY LIABILITIES - Changes in Liability for Unpaid Policy Claims (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Liability for Unpaid Claims and Claims Expenses      
Unpaid supplemental health claims, beginning of year $ 4,392 $ 4,045  
Net balance, beginning of year 4,392    
Less claims paid during the year on claims incurred during:      
Net balance, end of year 4,584 4,392  
Total liability for unpaid policy claims 4,584 4,392 $ 4,045
Health insurance      
Liability for Unpaid Claims and Claims Expenses      
Unpaid supplemental health claims, beginning of year 3,884 3,707 3,548
Less reinsurance recoverables 30 27 26
Net balance, beginning of year 3,854 3,680 3,522
Add claims incurred during the year related to:      
Current year 7,101 6,979 7,037
Prior years (563) (518) (465)
Total incurred 6,538 6,461 6,572
Less claims paid during the year on claims incurred during:      
Current year 4,612 4,530 4,613
Prior years 1,898 1,822 1,865
Total paid 6,510 6,352 6,478
Effect of foreign exchange rate changes on unpaid claims 43 65 64
Net balance, end of year 3,925 3,854 3,680
Add reinsurance recoverables 27 30 27
Total liability for unpaid policy claims 3,952 3,884 3,707
Life insurance      
Liability for Unpaid Claims and Claims Expenses      
Unpaid supplemental health claims, beginning of year 508 338  
Less claims paid during the year on claims incurred during:      
Total liability for unpaid policy claims $ 632 $ 508 $ 338
v3.10.0.1
REINSURANCE Additional Information (Detail)
$ in Millions, ¥ in Billions
 12 Months Ended
Dec. 31, 2018
JPY (¥)
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Effects of Reinsurance [Line Items]      
Percent change in spot yen/dollar exchange rate   2.00%  
Percent change in ceded reserves   2.00%  
Aflac Japan      
Effects of Reinsurance [Line Items]      
Committed reinsurance facility | ¥ ¥ 110    
Aflac Japan | Closed block      
Effects of Reinsurance [Line Items]      
Reinsurance deferred profit liability   $ 1,000  
Reinsurance recoverable   $ 941 $ 908
v3.10.0.1
REINSURANCE Effect of Reinsurance on Premiums and Benefits and Claims (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Effects of Reinsurance [Line Items]                      
Direct premium income                 $ 19,018 $ 18,875 $ 19,592
Ceded premiums                 (555) (566) (608)
Assumed premiums earned                 214 222 241
Net premium income $ 4,591 $ 4,636 $ 4,706 $ 4,745 $ 4,580 $ 4,648 $ 4,665 $ 4,638 18,677 18,531 19,225
Direct benefits and claims                 12,293 12,486 13,240
Benefits and claims, net                 12,000 12,181 12,919
All other                      
Effects of Reinsurance [Line Items]                      
Ceded premiums                 (58) (51) (48)
Assumed premiums earned                 6 6 7
Ceded benefits and claims                 (44) (44) (38)
Assumed benefits and claims from other companies                 2 3 4
Aflac Japan                      
Effects of Reinsurance [Line Items]                      
Net premium income                 12,762 12,752 13,537
Benefits and claims, net                 8,913 9,087 9,828
Aflac Japan | Closed block                      
Effects of Reinsurance [Line Items]                      
Ceded premiums                 (497) (515) (560)
Assumed premiums earned                 208 216 234
Ceded benefits and claims                 (450) (473) (509)
Assumed benefits and claims from other companies                 209 209 222
Intercompany eliminations                      
Effects of Reinsurance [Line Items]                      
Ceded benefits and claims                 43 51 58
Assumed benefits and claims from other companies                 $ (53) $ (51) $ (58)
v3.10.0.1
NOTES PAYABLE - Additional Information (Detail)
$ in Millions, ¥ in Billions
 1 Months Ended 12 Months Ended
Oct. 31, 2018
USD ($)
series
Oct. 31, 2017
JPY (¥)
Jan. 31, 2017
JPY (¥)
Dec. 31, 2016
USD ($)
Sep. 30, 2016
USD ($)
series
Mar. 31, 2015
USD ($)
series
Nov. 30, 2014
USD ($)
Jun. 30, 2013
USD ($)
Feb. 29, 2012
USD ($)
Aug. 31, 2010
USD ($)
Dec. 31, 2009
USD ($)
Dec. 31, 2016
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Nov. 30, 2018
USD ($)
Oct. 31, 2018
JPY (¥)
series
Dec. 31, 2017
USD ($)
Dec. 31, 2017
JPY (¥)
Sep. 30, 2016
JPY (¥)
series
Mar. 31, 2015
JPY (¥)
series
Nov. 30, 2014
JPY (¥)
Jun. 30, 2013
JPY (¥)
Feb. 29, 2012
JPY (¥)
Debt Instrument [Line Items]                                              
Number of series of senior unsecured term loan facilities | series         2                           2        
Number of series of senior notes issued through a U.S. public debt offering (in series) | series 3       2 2                   3     2 2      
4.750% senior notes due January 2049                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate 4.75%                       4.75% 4.75%   4.75%              
Debt instrument, term 30 years                                            
Debt instrument, redemption, description These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.                                            
Debt instrument, principal amount $ 550                                            
1.159% senior notes due October 2030                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate 1.159%                       1.159% 1.159%   1.159%              
Debt instrument, term 12 years                                            
Debt instrument, principal amount | ¥                           ¥ 29.3   ¥ 29.3              
1.488% senior notes due October 2033                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate 1.488%                       1.488% 1.488%   1.488%              
Debt instrument, term 15 years                                            
Debt instrument, principal amount | ¥                           ¥ 15.2   ¥ 15.2              
1.750% senior notes due October 2038                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate 1.75%                       1.75% 1.75%   1.75%              
Debt instrument, term 20 years                                            
Debt instrument, principal amount | ¥                           ¥ 8.9   ¥ 8.9              
2.108% subordinated notes due October 2047                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate   2.108%                     2.108% 2.108%     2.108% 2.108%          
Debt instrument, term   30 years                                          
Debt instrument, redemption, description   The debentures are redeemable (i) at any time, in whole but not in part, upon the occurrence of certain tax events or certain rating agency events, as specified in the indenture governing the terms of the debentures or (ii) on or after October?23, 2027, in whole or in part, at a redemption price equal to their principal amount plus accrued and unpaid interest to, but excluding, the date of redemption.                                          
Debt instrument, call date, earliest   Oct. 23, 2027                                          
Debt instrument, interest rate terms   The debentures bear interest at an initial rate of 2.108% per annum through October 22, 2027, or earlier redemption. Thereafter, the rate of the interest of the debentures will be reset every five years at a rate of interest equal to the then-current JPY 5-year Swap Offered Rate plus 205 basis points.                                          
Debt instrument, principal amount | ¥   ¥ 60.0                       ¥ 60.0       ¥ 60.0          
.932% senior notes due January 2027                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate     0.932%                   0.932% 0.932%     0.932% 0.932%          
Debt instrument, term     10 years                                        
Debt instrument, principal amount | ¥     ¥ 60.0                     ¥ 60.0       ¥ 60.0          
2.875% senior notes due October 2026                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate         2.875%               2.875% 2.875%     2.875% 2.875% 2.875%        
Debt instrument, term         10 years                                    
Debt instrument, principal amount         $ 300                                    
4.00% senior notes due October 2046                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate         4.00%               4.00% 4.00%     4.00% 4.00% 4.00%        
Debt instrument, term         30 years                                    
Debt instrument, principal amount         $ 400                                    
Yen-denominated loans                                              
Debt Instrument [Line Items]                                              
Debt instrument, principal amount | ¥                                     ¥ 30.0        
Yen-denominated loan variable interest rate due September 2021                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate                         0.32% 0.32%     0.32% 0.32%          
Debt instrument, description of variable rate basis         Tokyo interbank market rate (TIBOR), or alternate TIBOR, if applicable, plus the applicable TIBOR margin                                    
Debt instrument, term         5 years                                    
Debt instrument, interest rate terms         bears an interest rate per annum equal to the Tokyo interbank market rate (TIBOR), or alternate TIBOR, if applicable, plus the applicable TIBOR margin and has a five-year maturity. The applicable margin ranges between .20% and .60%, depending on the Parent Company's debt ratings as of the date of determination.                                    
Debt instrument, principal amount | ¥                           ¥ 5.0       ¥ 5.0 5.0        
Yen-denominated loan variable interest rate due September 2023                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate                         0.47% 0.47%     0.47% 0.47%          
Debt instrument, description of variable rate basis         TIBOR, or alternate TIBOR, if applicable, plus the applicable TIBOR margin                                    
Debt instrument, term         7 years                                    
Debt instrument, interest rate terms         bears an interest rate per annum equal to TIBOR, or alternate TIBOR, if applicable, plus the applicable TIBOR margin and has a seven-year maturity. The applicable margin ranges between .35% and .75%, depending on the Parent Company's debt ratings as of the date of determination.                                    
Debt instrument, principal amount | ¥                           ¥ 25.0       ¥ 25.0 ¥ 25.0        
2.40% senior notes paid November 2018                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate           2.40%                 2.40%   2.40% 2.40%   2.40%      
Debt instrument, term           5 years                                  
Debt instrument effective principal amount after cross currency swap | ¥                                       ¥ 67.0      
Debt instrument, principal amount           $ 550                 $ 550                
Debt instrument, effective interest rate           0.24%                           0.24%      
3.25% senior notes due March 2025                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate           3.25%             3.25% 3.25%     3.25% 3.25%   3.25%      
Debt instrument, term           10 years                                  
Debt instrument effective principal amount after cross currency swap | ¥                                       ¥ 55.0      
Debt instrument, principal amount           $ 450             $ 450                    
Debt instrument, effective interest rate           0.82%                           0.82%      
3.625% senior notes due November 2024                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate             3.625%           3.625% 3.625%     3.625% 3.625%     3.625%    
Debt instrument, term             10 years                                
Debt instrument, redemption, description             These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.                                
Debt instrument effective principal amount after cross currency swap | ¥                                         ¥ 85.3    
Debt instrument, principal amount             $ 750           $ 750                    
Debt instrument, effective interest rate             1.00%                           1.00%    
3.625% senior notes due June 2023                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate               3.625%         3.625% 3.625%     3.625% 3.625%       3.625%  
Debt instrument, term               10 years                              
Debt instrument, redemption, description               These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the treasury rate plus 20 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.                              
Debt instrument effective principal amount after cross currency swap | ¥                                           ¥ 69.8  
Debt instrument, principal amount               $ 700         $ 700                    
Debt instrument, effective interest rate               1.50%                           1.50%  
4.00% senior notes due February 2022                                              
Debt Instrument [Line Items]                                              
Debt instrument, interest rate                 4.00%       4.00% 4.00%     4.00% 4.00%         4.00%
Debt instrument, term                 10 years                            
Debt instrument effective principal amount after cross currency swap | ¥                                             ¥ 27.0
Debt instrument, principal amount                 $ 350       $ 350                    
Debt instrument, effective interest rate                 2.07%                           2.07%
6.90% senior notes due December 2039                                              
Debt Instrument [Line Items]                                              
Repayments of debt       $ 176                                      
Debt instrument, interest rate       6.90%               6.90% 6.90% 6.90%     6.90% 6.90%          
Debt instrument, term                     30 years                        
Debt instrument, principal amount                     $ 400                        
6.45% senior notes due August 2040                                              
Debt Instrument [Line Items]                                              
Repayments of debt       $ 193                                      
Debt instrument, interest rate       6.45%               6.45% 6.45% 6.45%     6.45% 6.45%          
Debt instrument, term                   30 years                          
Debt instrument, principal amount                   $ 450                          
Senior Notes due 2039 and 2040                                              
Debt Instrument [Line Items]                                              
Expense on extinguishment of debt                       $ 137                      
Senior Notes                                              
Debt Instrument [Line Items]                                              
Debt instrument, principal amount         $ 700 $ 1,000                   ¥ 53.4              
Notes Payable                                              
Debt Instrument [Line Items]                                              
Debt instrument, debt default, amount                         $ 0       $ 0            
Lower Limit | Yen-denominated loan variable interest rate due September 2021                                              
Debt Instrument [Line Items]                                              
Debt instrument, basis spread on variable rate         0.20%                                    
Lower Limit | Yen-denominated loan variable interest rate due September 2023                                              
Debt Instrument [Line Items]                                              
Debt instrument, basis spread on variable rate         0.35%                                    
Upper Limit | Yen-denominated loan variable interest rate due September 2021                                              
Debt Instrument [Line Items]                                              
Debt instrument, basis spread on variable rate         0.60%                                    
Upper Limit | Yen-denominated loan variable interest rate due September 2023                                              
Debt Instrument [Line Items]                                              
Debt instrument, basis spread on variable rate         0.75%                                    
Line of Credit                                              
Debt Instrument [Line Items]                                              
Debt instrument, debt default, amount                         $ 0       $ 0            
v3.10.0.1
NOTES PAYABLE - Summary of Notes Payable (Detail)
$ in Millions, ¥ in Billions
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Nov. 30, 2018
USD ($)
Oct. 31, 2018
USD ($)
Oct. 31, 2018
JPY (¥)
Dec. 31, 2017
USD ($)
Dec. 31, 2017
JPY (¥)
Oct. 31, 2017
JPY (¥)
Jan. 31, 2017
JPY (¥)
Dec. 31, 2016
Sep. 30, 2016
USD ($)
Sep. 30, 2016
JPY (¥)
Mar. 31, 2015
USD ($)
Nov. 30, 2014
USD ($)
Jun. 30, 2013
USD ($)
Feb. 29, 2012
USD ($)
Aug. 31, 2010
USD ($)
Dec. 31, 2009
USD ($)
Debt Instrument [Line Items]                                    
Notes payable $ 5,778         $ 5,289                        
2.40% senior notes paid November 2018                                    
Debt Instrument [Line Items]                                    
Notes payable 0         $ 548                        
Debt instrument, principal amount     $ 550                   $ 550          
Debt instrument, interest rate     2.40%     2.40% 2.40%           2.40%          
4.00% senior notes due February 2022                                    
Debt Instrument [Line Items]                                    
Notes payable 348         $ 348                        
Debt instrument, principal amount $ 350                             $ 350    
Debt instrument, interest rate 4.00% 4.00%       4.00% 4.00%                 4.00%    
3.625% senior notes due June 2023                                    
Debt Instrument [Line Items]                                    
Notes payable $ 698         $ 697                        
Debt instrument, principal amount $ 700                           $ 700      
Debt instrument, interest rate 3.625% 3.625%       3.625% 3.625%               3.625%      
3.625% senior notes due November 2024                                    
Debt Instrument [Line Items]                                    
Notes payable $ 746         $ 745                        
Debt instrument, principal amount $ 750                         $ 750        
Debt instrument, interest rate 3.625% 3.625%       3.625% 3.625%             3.625%        
3.25% senior notes due March 2025                                    
Debt Instrument [Line Items]                                    
Notes payable $ 447         $ 446                        
Debt instrument, principal amount $ 450                       $ 450          
Debt instrument, interest rate 3.25% 3.25%       3.25% 3.25%           3.25%          
2.875% senior notes due October 2026                                    
Debt Instrument [Line Items]                                    
Notes payable $ 297         $ 297                        
Debt instrument, principal amount                     $ 300              
Debt instrument, interest rate 2.875% 2.875%       2.875% 2.875%       2.875% 2.875%            
6.90% senior notes due December 2039                                    
Debt Instrument [Line Items]                                    
Notes payable $ 220         $ 220                        
Debt instrument, principal amount                                   $ 400
Debt instrument, interest rate 6.90% 6.90%       6.90% 6.90%     6.90%                
6.45% senior notes due August 2040                                    
Debt Instrument [Line Items]                                    
Notes payable $ 254         $ 254                        
Debt instrument, principal amount                                 $ 450  
Debt instrument, interest rate 6.45% 6.45%       6.45% 6.45%     6.45%                
4.00% senior notes due October 2046                                    
Debt Instrument [Line Items]                                    
Notes payable $ 394         $ 394                        
Debt instrument, principal amount                     $ 400              
Debt instrument, interest rate 4.00% 4.00%       4.00% 4.00%       4.00% 4.00%            
4.750% senior notes due January 2049                                    
Debt Instrument [Line Items]                                    
Notes payable $ 540         $ 0                        
Debt instrument, principal amount       $ 550                            
Debt instrument, interest rate 4.75% 4.75%   4.75% 4.75%                          
.932% senior notes due January 2027                                    
Debt Instrument [Line Items]                                    
Notes payable $ 538         $ 528                        
Debt instrument, principal amount | ¥   ¥ 60.0         ¥ 60.0   ¥ 60.0                  
Debt instrument, interest rate 0.932% 0.932%       0.932% 0.932%   0.932%                  
1.159% senior notes due October 2030                                    
Debt Instrument [Line Items]                                    
Notes payable $ 262         $ 0                        
Debt instrument, principal amount | ¥   ¥ 29.3     ¥ 29.3                          
Debt instrument, interest rate 1.159% 1.159%   1.159% 1.159%                          
1.488% senior notes due October 2033                                    
Debt Instrument [Line Items]                                    
Notes payable $ 136         0                        
Debt instrument, principal amount | ¥   ¥ 15.2     ¥ 15.2                          
Debt instrument, interest rate 1.488% 1.488%   1.488% 1.488%                          
1.750% senior notes due October 2038                                    
Debt Instrument [Line Items]                                    
Notes payable $ 79         0                        
Debt instrument, principal amount | ¥   ¥ 8.9     ¥ 8.9                          
Debt instrument, interest rate 1.75% 1.75%   1.75% 1.75%                          
2.108% subordinated notes due October 2047                                    
Debt Instrument [Line Items]                                    
Notes payable $ 536         $ 526                        
Debt instrument, principal amount | ¥   ¥ 60.0         ¥ 60.0 ¥ 60.0                    
Debt instrument, interest rate 2.108% 2.108%       2.108% 2.108% 2.108%                    
Yen-denominated loan variable interest rate due September 2021                                    
Debt Instrument [Line Items]                                    
Notes payable $ 45         $ 44                        
Debt instrument, principal amount | ¥   ¥ 5.0         ¥ 5.0         ¥ 5.0            
Debt instrument, interest rate 0.32% 0.32%       0.32% 0.32%                      
Yen-denominated loan variable interest rate due September 2023                                    
Debt Instrument [Line Items]                                    
Notes payable $ 225         $ 220                        
Debt instrument, principal amount | ¥   ¥ 25.0         ¥ 25.0         ¥ 25.0            
Debt instrument, interest rate 0.47% 0.47%       0.47% 0.47%                      
Capitalized lease obligations                                    
Debt Instrument [Line Items]                                    
Notes payable $ 13         $ 22                        
v3.10.0.1
NOTES PAYABLE - Aggregate Contractual Maturities of Notes Payable (Detail)
$ in Millions
Dec. 31, 2018
USD ($)
Debt Instrument [Line Items]  
2019 $ 5
2020 3
2021 47
2022 351
2023 926
Thereafter 4,494
Total 5,826
Long-term debt  
Debt Instrument [Line Items]  
2019 0
2020 0
2021 45
2022 350
2023 925
Thereafter 4,493
Total 5,813
Capitalized lease obligations  
Debt Instrument [Line Items]  
2019 5
2020 3
2021 2
2022 1
2023 1
Thereafter 1
Total $ 13
v3.10.0.1
NOTES PAYABLE - Summary of Notes Payable (Parenthetical) (Detail)
$ in Millions, ¥ in Billions
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Nov. 30, 2018
USD ($)
Oct. 31, 2018
USD ($)
Oct. 31, 2018
JPY (¥)
Dec. 31, 2017
JPY (¥)
Oct. 31, 2017
JPY (¥)
Jan. 31, 2017
JPY (¥)
Dec. 31, 2016
Sep. 30, 2016
USD ($)
Sep. 30, 2016
JPY (¥)
Mar. 31, 2015
USD ($)
Nov. 30, 2014
USD ($)
Jun. 30, 2013
USD ($)
Feb. 29, 2012
USD ($)
Aug. 31, 2010
USD ($)
Dec. 31, 2009
USD ($)
2.40% senior notes paid November 2018                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate     2.40%     2.40%           2.40%          
Debt instrument, principal amount     $ 550                 $ 550          
4.00% senior notes due February 2022                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 4.00% 4.00%       4.00%                 4.00%    
Debt instrument, principal amount $ 350                           $ 350    
3.625% senior notes due June 2023                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 3.625% 3.625%       3.625%               3.625%      
Debt instrument, principal amount $ 700                         $ 700      
3.625% senior notes due November 2024                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 3.625% 3.625%       3.625%             3.625%        
Debt instrument, principal amount $ 750                       $ 750        
3.25% senior notes due March 2025                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 3.25% 3.25%       3.25%           3.25%          
Debt instrument, principal amount $ 450                     $ 450          
2.875% senior notes due October 2026                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 2.875% 2.875%       2.875%       2.875% 2.875%            
Debt instrument, principal amount                   $ 300              
6.90% senior notes due December 2039                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 6.90% 6.90%       6.90%     6.90%                
Debt instrument, principal amount                                 $ 400
6.45% senior notes due August 2040                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 6.45% 6.45%       6.45%     6.45%                
Debt instrument, principal amount                               $ 450  
4.00% senior notes due October 2046                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 4.00% 4.00%       4.00%       4.00% 4.00%            
Debt instrument, principal amount                   $ 400              
4.750% senior notes due January 2049                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 4.75% 4.75%   4.75% 4.75%                        
Debt instrument, principal amount       $ 550                          
.932% senior notes due January 2027                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 0.932% 0.932%       0.932%   0.932%                  
Debt instrument, principal amount | ¥   ¥ 60.0       ¥ 60.0   ¥ 60.0                  
1.159% senior notes due October 2030                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 1.159% 1.159%   1.159% 1.159%                        
Debt instrument, principal amount | ¥   ¥ 29.3     ¥ 29.3                        
1.488% senior notes due October 2033                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 1.488% 1.488%   1.488% 1.488%                        
Debt instrument, principal amount | ¥   ¥ 15.2     ¥ 15.2                        
1.750% senior notes due October 2038                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 1.75% 1.75%   1.75% 1.75%                        
Debt instrument, principal amount | ¥   ¥ 8.9     ¥ 8.9                        
2.108% subordinated notes due October 2047                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 2.108% 2.108%       2.108% 2.108%                    
Debt instrument, principal amount | ¥   ¥ 60.0       ¥ 60.0 ¥ 60.0                    
Yen-denominated loan variable interest rate due September 2021                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 0.32% 0.32%       0.32%                      
Debt instrument, principal amount | ¥   ¥ 5.0       ¥ 5.0         ¥ 5.0            
Yen-denominated loan variable interest rate due September 2023                                  
Debt Instrument [Line Items]                                  
Debt instrument, interest rate 0.47% 0.47%       0.47%                      
Debt instrument, principal amount | ¥   ¥ 25.0       ¥ 25.0         ¥ 25.0            
v3.10.0.1
NOTES PAYABLE - Summary of Lines of Credit (Detail) - 12 months ended Dec. 31, 2018
¥ in Millions, $ in Millions
USD ($)
JPY (¥)
$100 million line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description The rate quoted by the bank and agreed upon at the time of borrowing  
Line of credit facility term 364 days  
Line of credit facility, maximum borrowing capacity | $ $ 100  
Line of credit facility, amount outstanding | $ $ 0  
100.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description A rate per annum equal to (a) Tokyo interbank market rate (TIBOR) plus, the alternative applicable TIBOR margin during the availability period from the closing date to the commitment termination date or (b) the TIBOR rate offered by the agent to major banks in yen for the applicable period plus, the applicable alternative TIBOR margin during the term out period  
Line of credit facility term 3 years  
Line of credit facility, maximum borrowing capacity | ¥   ¥ 100,000
Line of credit facility, amount outstanding | ¥   0
55.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description A rate per annum equal to, at the Company's option, either, (a) London Interbank Offered Rate (LIBOR) adjusted for certain costs or (b) a base rate determined by reference to the highest of (1) the federal funds rate plus 1/2 of 1%, (2) the rate of interest for such day announced by Mizuho Bank, Ltd. as its prime rate, or (3) the eurocurrency rate for an interest period of one month plus 1.00%, in each case plus an applicable margin  
Line of credit facility term 5 years  
Line of credit facility, maximum borrowing capacity | ¥   55,000
Line of credit facility, amount outstanding | ¥   0
$50 million line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description A rate per annum equal to, at the Parent Company's option, either (a) a eurocurrency rate determined by reference to the agent's LIBOR for the interest period relevant to such borrowing or (b) the base rate determined by reference to the greater of (i) the prime rate as determined by the agent, and (ii) the sum of 0.50% and the federal funds rate for such day  
Line of credit facility, maximum borrowing capacity | $ $ 50  
Line of credit facility, amount outstanding | $ $ 0  
$250 million line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description USD three-month LIBOR plus 75 basis points per annum  
Line of credit facility term 364 days  
Line of credit facility, maximum borrowing capacity | $ $ 250  
Line of credit facility, amount outstanding | $ $ 0  
Debt instrument, term 3 months  
50.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, interest rate description Three-month TIBOR plus 80 basis points per annum  
Line of credit facility term 364 days  
Line of credit facility, maximum borrowing capacity | ¥   50,000
Line of credit facility, amount outstanding | ¥   ¥ 0
Debt instrument, term 3 months  
Lower Limit | 100.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, commitment fee percentage 0.30%  
Lower Limit | 55.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, commitment fee percentage 0.085%  
Upper Limit | $100 million line of credit    
Line of Credit Facility [Line Items]    
Debt instrument, term 3 months  
Upper Limit | 100.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, commitment fee percentage 0.50%  
Upper Limit | 55.0 billion yen line of credit    
Line of Credit Facility [Line Items]    
Line of credit facility, commitment fee percentage 0.225%  
Upper Limit | $50 million line of credit    
Line of Credit Facility [Line Items]    
Debt instrument, term 3 months  
v3.10.0.1
INCOME TAXES - Additional Information (Detail) - USD ($)
$ in Millions
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2018
Dec. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Taxes [Line Items]          
Japan Tax Rate   28.20% 28.00% 28.20% 28.80%
U.S. federal statutory corporate income tax rate 21.00%   21.00% 35.00% 35.00%
Income Tax Expense, Gross, Continuing Operations, Adjustment of Deferred Tax Assets   $ 1,000.0      
Income Tax Benefit, Gross, Continuing Operations, Adjustment of Deferred Tax Liabilities   2,900.0      
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax Asset (Liability)   (1,900.0) $ 0.4    
Deferred Tax Assets, Valuation Allowance   657.0 $ 738.0 $ 657.0  
Non-life operating loss carryforwards, limitations     only 35% of non-life operating losses can be offset against life insurance taxable income each year    
Operating Loss Carryforwards     $ 21.0    
Unrecognized tax benefit, deductibility highly certain, timing uncertain   13.0 14.0 13.0  
Unrecognized tax benefits, permanent uncertainties     1.0    
Unrecognized tax benefits, interest and penalties expense     1.0 1.0 $ 13.0
Unrecognized tax benefits, accrued interest and penalties   $ 2.0 2.0 $ 2.0  
Anticipatory Foreign Tax Credit          
Income Taxes [Line Items]          
Deferred Tax Assets, Valuation Allowance     577.0    
Deferred Foreign Tax Credit          
Income Taxes [Line Items]          
Deferred Tax Assets, Valuation Allowance     161.0    
Capital Loss Carryforward          
Income Taxes [Line Items]          
Tax Credit Carryforward, Amount     22.0    
Expiring In Twenty Twenty One | Capital Loss Carryforward          
Income Taxes [Line Items]          
Tax Credit Carryforward, Amount     4.0    
Expiring In Twenty Twenty Three | Capital Loss Carryforward          
Income Taxes [Line Items]          
Tax Credit Carryforward, Amount     $ 18.0    
v3.10.0.1
INCOME TAXES - Components of Income Tax Expense (Benefit) Applicable to Pretax Earnings (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Reconciliation of Provision of Income Taxes [Line Items]                      
Current                 $ 1,379 $ 631 $ 884
Deferred                 (316) (1,217) 524
Total income tax expense $ 197 $ 301 $ 299 $ 265 $ (1,585) $ 359 $ 332 $ 306 1,063 (586) 1,408
Aflac U.S.                      
Reconciliation of Provision of Income Taxes [Line Items]                      
Current                 608 (91) 234
Deferred                 (409) (1,193) 388
Total income tax expense                 199 (1,284) 622
Aflac Japan                      
Reconciliation of Provision of Income Taxes [Line Items]                      
Current                 771 722 650
Deferred                 93 (24) 136
Total income tax expense                 $ 864 $ 698 $ 786
v3.10.0.1
INCOME TAXES - Principal Reasons for Differences and Related Tax Effects where Income Tax Expense Varies from Amount Computed by Applying Expected United States Tax Rate to Pretax Earnings (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]                      
Income taxes based on U.S. statutory rates                 $ 836 $ 1,406 $ 1,424
Foreign rate differential                 220 0 0
Write-down of U.S. deferred tax liabilities for tax reform change                 0 (1,933) 0
Utilization of foreign tax credit                 (3) (27) (30)
Nondeductible expenses                 21 10 8
Other, net                 (11) (42) 6
Total income tax expense $ 197 $ 301 $ 299 $ 265 $ (1,585) $ 359 $ 332 $ 306 $ 1,063 $ (586) $ 1,408
v3.10.0.1
INCOME TAXES - Total Income Tax Expense (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]                      
Statements of earnings $ 197 $ 301 $ 299 $ 265 $ (1,585) $ 359 $ 332 $ 306 $ 1,063 $ (586) $ 1,408
Other comprehensive income (loss):                      
Unrealized foreign currency translation gains (losses) during period                 10 52 70
Unrealized gains (losses) on investment securities:                      
Unrealized holding gains (losses) on investment securities during period                 (787) 575 962
Reclassification adjustment for realized (gains) losses on investment securities included in net earnings                 (12) 1 18
Unrealized gains (losses) on derivatives during period                 0 0 1
Pension liability adjustment during period                 (8) 3 (16)
Total income tax expense (benefit) related to items of other comprehensive income (loss)                 (797) 631 1,035
Additional paid-in capital (exercise of stock options)                 0 0 (10)
Total income taxes                 $ 266 $ 45 $ 2,433
v3.10.0.1
INCOME TAXES - Income Tax Effects of Temporary Differences that Gave Rise to Deferred Income Tax Assets and Liabilities (Detail) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Deferred income tax liabilities:    
Deferred policy acquisition costs $ 3,404 $ 3,285
Unrealized gains and other basis differences on investments 1,307 2,882
Premiums receivable 149 104
Policy benefit reserves 3,828 3,557
Total deferred income tax liabilities 8,688 9,828
Deferred income tax assets:    
Unfunded retirement benefits 8 8
Other accrued expenses 40 141
Policy and contract claims 775 870
Foreign currency loss on Aflac Japan 38 67
Deferred compensation 163 155
Capital loss carryforwards 5 0
Depreciation 119 114
Anticipatory foreign tax credit 4,040 4,504
Deferred foreign tax credit 591 0
Other 150 57
Total deferred income tax assets before valuation allowance 5,929 5,916
Valuation allowance (738) (657)
Total deferred income tax assets after valuation allowance 5,191 5,259
Net deferred income tax liability 3,497 4,569
Current income tax liability 523 176
Total income tax liability $ 4,020 $ 4,745
v3.10.0.1
INCOME TAXES - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]    
Balance, beginning of year $ 14 $ 294
Additions for tax positions of prior years 1 0
Reductions for tax positions of prior years 0 (280)
Balance, end of year $ 15 $ 14
v3.10.0.1
SHAREHOLDERS' EQUITY - Additional Information (Detail)
shares in Millions
 12 Months Ended
Dec. 31, 2018
Vote
shares
Dec. 31, 2017
shares
Dec. 31, 2016
shares
Stockholders Equity Note [Line Items]      
Remaining common stock available for purchase under share repurchase authorizations | shares 69.0    
Common stock, voting rights are generally entitled to one vote per share until they have been held by the same beneficial owner for a continuous period of 48 months, at which time they become entitled to 10 votes per share.    
Share Held For Less Than A Continuous Forty Eight Month Period      
Stockholders Equity Note [Line Items]      
Common stock, votes per share | Vote 1    
Share Held For Continuous Forty Eight Month Period      
Stockholders Equity Note [Line Items]      
Common stock, votes per share | Vote 10    
Share Repurchase Program      
Stockholders Equity Note [Line Items]      
Stock acquired in open market, shares | shares 28.9 35.5 43.2
v3.10.0.1
SHAREHOLDERS' EQUITY - Reconciliation of Number of Shares of Common Stock (Detail) - shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Common Stock Issued [Roll Forward]      
Balance, beginning of period 1,345,762 1,342,498 1,339,446
Exercise of stock options and issuance of restricted shares 1,778 3,264 3,052
Balance, end of period 1,347,540 1,345,762 1,342,498
Treasury Stock [Roll Forward]      
Balance, beginning of period 564,852 530,877 490,686
Exercise of stock options (1,874) (5,766) (4,122)
Balance, end of period 592,254 564,852 530,877
Shares outstanding, end of period 755,286 780,910 811,621
Treasury Stock      
Treasury Stock [Roll Forward]      
Stock acquired in open market, shares 28,949 35,510 43,236
Other purchases 392 1,018 662
Shares issued to AFL Stock Plan (1,306) (1,782) (2,130)
Exercise of stock options (519) (734) (1,366)
Other dispositions (114) (37) (211)
v3.10.0.1
SHAREHOLDERS' EQUITY - Anti-Dilutive Share-Based Awards Excluded from Calculation of Diluted Earnings Per Share (Detail) - shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Stockholders' Equity Note [Abstract]      
Anti-dilutive share-based awards 44 510 1,822
v3.10.0.1
SHAREHOLDERS' EQUITY - Weighted-Average Shares Used in Calculating Earnings Per Share (Details) - shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Stockholders' Equity Note [Abstract]      
Weighted-average outstanding shares used for calculating basic EPS 769,588 792,042 822,942
Dilutive effect of share-based awards 5,062 5,819 4,899
Weighted-average outstanding shares used for calculating diluted EPS 774,650 797,861 827,841
v3.10.0.1
SHAREHOLDERS' EQUITY - Changes in Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accumulated Other Comprehensive Income [Roll Forward]      
Balance, beginning of period [1] $ 4,028 $ 2,630 $ 625
Other comprehensive income loss before reclassifications net of tax [1] (2,150) 1,386 2,037
Amounts reclassified from accumulated other comprehensive income net of tax [1] 47 12 (32)
Other comprehensive income (loss), net of tax [1] (2,103) 1,398 2,005
Balance, end of period [1] 2,151 4,028 2,630
Accounting Standards Update 2016-01      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] (148)    
Accounting Standards Update 2018-02      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] 374    
Unrealized foreign currency translation gains (losses)      
Accumulated Other Comprehensive Income [Roll Forward]      
Balance, beginning of period [1] (1,750) (1,983) (2,196)
Other comprehensive income loss before reclassifications net of tax [1] 228 233 213
Amounts reclassified from accumulated other comprehensive income net of tax [1] 0 0 0
Other comprehensive income (loss), net of tax [1] 228 233 213
Balance, end of period [1] (1,847) (1,750) (1,983)
Unrealized foreign currency translation gains (losses) | Accounting Standards Update 2016-01      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] 0    
Unrealized foreign currency translation gains (losses) | Accounting Standards Update 2018-02      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] (325)    
Unrealized gains (losses) on investment securities      
Accumulated Other Comprehensive Income [Roll Forward]      
Balance, beginning of period [1] 5,964 4,805 2,986
Other comprehensive income loss before reclassifications net of tax [1] (2,350) 1,158 1,854
Amounts reclassified from accumulated other comprehensive income net of tax [1] 34 1 (35)
Other comprehensive income (loss), net of tax [1] (2,316) 1,159 1,819
Balance, end of period [1] 4,234 5,964 4,805
Unrealized gains (losses) on investment securities | Accounting Standards Update 2016-01      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] (148)    
Unrealized gains (losses) on investment securities | Accounting Standards Update 2018-02      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] 734    
Unrealized gains (losses) on derivatives      
Accumulated Other Comprehensive Income [Roll Forward]      
Balance, beginning of period [1] (23) (24) (26)
Other comprehensive income loss before reclassifications net of tax [1] 2 1 2
Amounts reclassified from accumulated other comprehensive income net of tax [1] 0 0 0
Other comprehensive income (loss), net of tax [1] 2 1 2
Balance, end of period [1] (24) (23) (24)
Unrealized gains (losses) on derivatives | Accounting Standards Update 2016-01      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] 0    
Unrealized gains (losses) on derivatives | Accounting Standards Update 2018-02      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] (3)    
Pension liability adjustment      
Accumulated Other Comprehensive Income [Roll Forward]      
Balance, beginning of period [1] (163) (168) (139)
Other comprehensive income loss before reclassifications net of tax [1] (30) (6) (32)
Amounts reclassified from accumulated other comprehensive income net of tax [1] 13 11 3
Other comprehensive income (loss), net of tax [1] (17) 5 (29)
Balance, end of period [1] (212) $ (163) $ (168)
Pension liability adjustment | Accounting Standards Update 2016-01      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] 0    
Pension liability adjustment | Accounting Standards Update 2018-02      
Accumulated Other Comprehensive Income [Roll Forward]      
Amounts reclassified from accumulated other comprehensive income net of tax [1] $ (32)    
[1] All amounts in the table above are net of tax.
v3.10.0.1
SHAREHOLDERS' EQUITY - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 1 Months Ended 3 Months Ended 12 Months Ended
Jan. 31, 2018
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                        
Other-than-temporary impairment losses realized                   $ (81)    
Other-than-temporary impairment losses realized                     $ (37) $ (85)
Other gains (losses) [1]                   (349) (114) 71
Total before tax   $ 722 $ 1,146 $ 1,131 $ 982 $ 999 $ 1,075 $ 1,045 $ 898 3,983 4,018 4,067
Income tax (expense) benefit   $ (197) $ (301) $ (299) $ (265) $ 1,585 $ (359) $ (332) $ (306) (1,063) 586 (1,408)
Net of tax                   $ 2,920 $ 4,604 $ 2,659
Blended statutory income tax rate                   27.00%    
U.S. federal statutory corporate income tax rate 21.00%                 21.00% 35.00% 35.00%
Reclassification out of Accumulated Other Comprehensive Income                        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                        
Net of tax                   $ (47) $ (12) $ 32
Reclassification out of Accumulated Other Comprehensive Income | Unrealized gains (losses) on investment securities                        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                        
Other-than-temporary impairment losses realized                   (63)    
Other-than-temporary impairment losses realized                     (29) (83)
Other gains (losses)                   17 27 136
Total before tax                   (46) (2) 53
Income tax (expense) benefit                   12 [2] 1 [3] (18) [3]
Net of tax                   (34) (1) 35
Reclassification out of Accumulated Other Comprehensive Income | Pension liability adjustment                        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                        
Acquisition and operating expense, actuarial gains (losses) [4]                   (18) (17) (15)
Acquisition and operating expenses, prior service (cost) credit [4]                   0 0 11
Income tax (expense) benefit                   5 [2] 6 [3] 1 [3]
Net of tax                   $ (13) $ (11) $ (3)
[1] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[2] Based on 27% blended tax rate
[3] Based on 35% tax rate
[4] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 14 for additional details).
v3.10.0.1
SHARE-BASED COMPENSATION - Additional Information (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
 1 Months Ended 12 Months Ended
Feb. 28, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value   $ 8.81 $ 7.64 $ 6.35  
Closing common stock price   $ 45.56      
Aggregate intrinsic value of stock options outstanding   $ 91      
Options outstanding - weighted-average remaining term (Yrs)   5 years      
In-the-money stock options exercisable   3,900      
Aggregate intrinsic value of stock options exercisable   $ 72      
Weighted-average remaining term of stock options exercisable (in years)   4 years 1 month 6 days      
Long-Term Incentive Plan          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Share-based compensation arrangement by share-based payment award, maximum number of shares issuable   75,000      
Share-based compensation arrangement by share-based payment award, maximum number of shares issuable other than options and stock appreciation rights   38,000      
Shares available for future grants under the long-term incentive plan   40,300      
Long-term incentive plan awards, term (in years)   10 years      
Long-term incentive plan, vesting period   3 years      
Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Restricted stock awards, grants in period   1,121 1,118 1,756  
Total compensation cost not yet recognized, restricted stock awards   $ 36      
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number of shares   3,407 3,634 3,736 3,630
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition   1 year      
Performance Based Vesting Condition | Restricted Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Long-term incentive plan, vesting period 3 years        
Restricted stock awards, grants in period 432        
Percentage of target award opportunities minimum   0.00%      
Percentage of target award opportunities maximum   200.00%      
Total compensation cost not yet recognized, restricted stock awards   $ 15      
Share-based compensation arrangement by share-based payment award, equity instruments other than options, nonvested, number of shares   799      
v3.10.0.1
SHARE-BASED COMPENSATION - Expense Recognized in Connection with Share-Based Awards (Detail) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]                      
Earnings before income taxes $ 722 $ 1,146 $ 1,131 $ 982 $ 999 $ 1,075 $ 1,045 $ 898 $ 3,983 $ 4,018 $ 4,067
Net earnings                 $ 2,920 $ 4,604 $ 2,659
Net earnings per share:                      
Basic (in dollars per share) $ 0.69 $ 1.10 $ 1.08 $ 0.92 $ 3.29 $ 0.91 $ 0.90 $ 0.74 $ 3.79 $ 5.81 $ 3.23
Diluted (in dollars per share) $ 0.69 $ 1.09 $ 1.07 $ 0.91 $ 3.27 $ 0.90 $ 0.89 $ 0.73 $ 3.77 $ 5.77 $ 3.21
Share Based Compensation Expense                      
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]                      
Earnings from continuing operations                 $ 57 $ 51 $ 68
Earnings before income taxes                 57 51 68
Net earnings                 $ 45 $ 35 $ 46
Net earnings per share:                      
Basic (in dollars per share)                 $ 0.06 $ 0.05 $ 0.06
Diluted (in dollars per share)                 $ 0.06 $ 0.05 $ 0.06
v3.10.0.1
SHARE-BASED COMPENSATION - Stock Option Activity (Detail) - $ / shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Stock Option Shares      
Beginning Balance 7,304 12,680 15,836
Granted 67 626 1,328
Canceled (167) (236) (362)
Exercised (1,874) (5,766) (4,122)
Ending Balance 5,330 7,304 12,680
Weighted-Average Exercise Price Per Share      
Beginning Balance $ 28.03 $ 26.28 $ 25.47
Granted 44.59 35.80 30.70
Canceled 32.11 24.95 27.82
Exercised 26.78 30.11 24.46
Ending Balance $ 28.54 $ 28.03 $ 26.28
v3.10.0.1
SHARE-BASED COMPENSATION - Shares Exercisable (Detail) - shares
shares in Thousands
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Shares exercisable, end of year 3,917 4,208 8,986
v3.10.0.1
SHARE-BASED COMPENSATION - Assumptions Used in Valuing Options Granted (Detail) - Employee stock option
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Line Items]      
Expected term (years) 7 years 5 years 10 months 24 days 6 years 4 months 24 days
Expected volatility 22.00% 26.00% 27.00%
Annual forfeiture rate 3.60% 3.40% 3.20%
Risk-free interest rate 2.50% 2.50% 2.20%
Dividend yield 2.40% 2.50% 2.90%
v3.10.0.1
SHARE-BASED COMPENSATION - Stock Options Outstanding and Exercisable (Detail) - $ / shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range $ 11.07      
Range of Exercise Prices Per Share - Upper Range $ 44.59      
Options Outstanding - Stock Option Shares 5,330 7,304 12,680 15,836
Options outstanding - weighted-average remaining term (Yrs) 5 years      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 28.54 $ 28.03 $ 26.28 $ 25.47
Options Exercisable - Stock Option Shares 3,917 4,208 8,986  
Options Exercisable - Weighted-Average Exercise Price Per Share $ 27.14      
$11.07 - $24.28        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range 11.07      
Range of Exercise Prices Per Share - Upper Range $ 24.28      
Options Outstanding - Stock Option Shares 1,181      
Options outstanding - weighted-average remaining term (Yrs) 1 year 9 months 18 days      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 20.76      
Options Exercisable - Stock Option Shares 1,181      
Options Exercisable - Weighted-Average Exercise Price Per Share $ 20.76      
$24.75 - $28.97        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range 24.75      
Range of Exercise Prices Per Share - Upper Range $ 28.97      
Options Outstanding - Stock Option Shares 1,718      
Options outstanding - weighted-average remaining term (Yrs) 4 years 9 months 18 days      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 27.76      
Options Exercisable - Stock Option Shares 1,026      
Options Exercisable - Weighted-Average Exercise Price Per Share $ 26.95      
$29.04 - $31.21        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range 29.04      
Range of Exercise Prices Per Share - Upper Range $ 31.21      
Options Outstanding - Stock Option Shares 1,226      
Options outstanding - weighted-average remaining term (Yrs) 5 years 9 months 18 days      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 30.77      
Options Exercisable - Stock Option Shares 1,221      
Options Exercisable - Weighted-Average Exercise Price Per Share $ 30.77      
$31.22 - $37.22        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range 31.22      
Range of Exercise Prices Per Share - Upper Range $ 37.22      
Options Outstanding - Stock Option Shares 1,134      
Options outstanding - weighted-average remaining term (Yrs) 7 years 6 months      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 34.44      
Options Exercisable - Stock Option Shares 488      
Options Exercisable - Weighted-Average Exercise Price Per Share $ 33.86      
$38.76 - $44.59        
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]        
Range of Exercise Prices Per Share - Lower Range 38.76      
Range of Exercise Prices Per Share - Upper Range $ 44.59      
Options Outstanding - Stock Option Shares 71      
Options outstanding - weighted-average remaining term (Yrs) 9 years 3 months 18 days      
Options Outstanding - Weighted-Average Exercise Price Per Share $ 44.21      
Options Exercisable - Stock Option Shares 1      
Options Exercisable - Weighted-Average Exercise Price Per Share $ 38.76      
v3.10.0.1
SHARE-BASED COMPENSATION - Summary of Stock Option Activity (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Total intrinsic value of options exercised $ 34 $ 87 $ 41
Cash received from options exercised 48 58 68
Tax benefit realized as a result of options exercised and restricted stock releases $ 25 $ 74 $ 45
v3.10.0.1
SHARE-BASED COMPENSATION - Key Assumptions Used to Value PBRS (Details) - Performance Based Vesting Condition - Restricted Stock
 12 Months Ended
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]  
Expected volatility (based on Aflac Inc. and peer group historical daily stock price) 16.48%
Expected life from grant date (years) 2 years 10 months 24 days
Risk-free interest rate (based on U.S. Treasury yields at the date of grant) 2.29%
v3.10.0.1
SHARE-BASED COMPENSATION - Restricted Stock Activity (Detail) - Restricted Stock - $ / shares
shares in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Shares      
Beginning balance 3,634 3,736 3,630
Granted 1,121 1,118 1,756
Canceled (105) (202) (152)
Vested (1,243) (1,018) (1,498)
Ending Balance 3,407 3,634 3,736
Weighted-Average Grant-Date Fair Value Per Share      
Beginning balance $ 32.40 $ 30.88 $ 29.21
Granted 44.27 36.48 30.84
Canceled 34.39 32.23 30.33
Vested 31.64 31.09 26.84
Ending Balance $ 36.52 $ 32.40 $ 30.88
v3.10.0.1
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Additional Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Statutory Accounting Practices [Line Items]      
Statutory accounting practices, statutory capital and surplus required $ 500    
Aflac      
Statutory Accounting Practices [Line Items]      
Net Income, Nebraska state basis 1,300 $ 2,600 $ 2,800
Capital and surplus, statutory accounting practices of the state or country basis 2,600 11,001  
Amount available for dividend distribution without prior approval from regulatory agency 1,300    
Dividends declared 12,300    
Non-cash extraordinary dividends 11,000    
Aflac Japan      
Statutory Accounting Practices [Line Items]      
Capital and surplus, statutory accounting practices of the state or country basis $ 6,400 $ 6,700  
v3.10.0.1
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Reconciliation of Capital and Surplus Between Sap and Practices Permitted by the State of Nebraska (Detail) - Aflac - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Statutory Accounting Practices [Line Items]    
Capital and surplus, Nebraska state basis $ 2,600 $ 11,001
Capital and surplus, NAIC basis 2,600 10,140
Lease Deposits    
Statutory Accounting Practices [Line Items]    
State permitted practice amount 0 (43)
Reinsurance    
Statutory Accounting Practices [Line Items]    
State permitted practice amount $ 0 $ (818)
v3.10.0.1
STATUTORY ACCOUNTING AND DIVIDEND RESTRICTIONS - Profit Remittances by Aflac Japan (Detail)
$ in Millions, ¥ in Billions
 12 Months Ended
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Dec. 31, 2017
USD ($)
Dec. 31, 2017
JPY (¥)
Dec. 31, 2016
USD ($)
Dec. 31, 2016
JPY (¥)
Insurance [Abstract]            
Profit remittances $ 808 ¥ 89.7 $ 1,150 ¥ 129.3 $ 1,286 ¥ 138.5
v3.10.0.1
BENEFIT PLANS - Additional Information (Detail) - USD ($)
shares in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2013
Jan. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Amount of years active employees have left to meet rule of 80 in order to be eligible for postretirement medical benefits       5 years  
Amount of years left to meet 15 year service requirement for active employees age 55 or older to be eligible for postretirement medical benefits       5 years  
Net periodic (benefit) cost, excluding service cost $ 25,000,000 $ 35,000,000 $ 17,000,000    
Transition obligation $ 0        
Percentage of matching contributions by the Company to employee's contributions to 401(k) plan 100.00% 50.00% 50.00%    
Defined contribution plan, special contribution, per employee         $ 500
Non-elective defined contribution percentage of employee compensation 2.00%        
Matching 401(k) plan contributions included in acquisition and operating expenses $ 18,000,000 $ 15,000,000 $ 11,000,000    
Shares of employer-issued common stock held for plan participants by plan trustee (in millions) 2.7        
Lower Limit          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Health care plan, retirement age and years of service combined years for eligibility (rule of 80)       80 years  
Health care plan, retirement age for eligibility, (in years)       55 years  
Health care plan, number of years of service for eligibility       15 years  
Upper Limit          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Percentage of matching contributions by the Company to employee's contributions to 401(k) plan 4.00% 6.00% 6.00%    
Other Postretirement Benefit Plans, Defined Benefit          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Defined benefit plan, future amortization of actuarial losses $ 1,000,000        
Defined benefit plan, plan assets, amount 0 $ 0 $ 0    
Associate Stock Bonus Plan          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Deferred policy acquisition costs, amount attributable to stock bonus plan $ 31,000,000 31,000,000 31,000,000    
Japan          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
AA corporate bonds average duration 20 years        
Japan | Pension Plan          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Defined benefit plan, future amortization of actuarial losses $ 4,000,000        
Defined benefit plan, expected contributions to the plan in the following year 33,000,000        
Defined benefit plan, plan assets, amount $ 289,000,000 270,000,000 229,000,000    
U.S.          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
AA corporate bonds average duration 17 years        
U.S. | Pension Plan          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Defined benefit plan, future amortization of actuarial losses $ 11,000,000        
Defined benefit plan, expected contributions to the plan in the following year 10,000,000        
Defined benefit plan, plan assets, amount 465,000,000 448,000,000 $ 359,000,000    
Level 1 | U.S. | Pension Plan | Cash and cash equivalents          
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]          
Defined benefit plan, plan assets, amount $ 39,000,000 $ 1,000,000      
v3.10.0.1
BENEFIT PLANS - Reconciliation of Funded Status of Basic Employee Defined-Benefit Pension Plans (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Other Postretirement Benefit Plans, Defined Benefit      
Projected benefit obligation:      
Benefit obligation, beginning of year $ 36 $ 37  
Service cost 0 0 $ 1
Interest cost 1 1 2
Actuarial (gain) loss 4 0  
Benefits and expenses paid (4) (2)  
Effect of foreign exchange rate changes 0 0  
Benefit obligation, end of year 37 36 37
Plan assets:      
Fair value of plan assets, beginning of year 0 0  
Actual return on plan assets 0 0  
Employer contributions 4 2  
Benefits and expenses paid (4) (2)  
Effect of foreign exchange rate changes 0 0  
Fair value of plan assets, end of year 0 0 0
Funded status of the plans [1] (37) (36)  
Amounts recognized in accumulated other comprehensive income:      
Net actuarial (gain) loss 9 6  
Prior service (credit) cost 0 0  
Total included in accumulated other comprehensive income 9 6  
Japan | Pension Plan      
Projected benefit obligation:      
Benefit obligation, beginning of year 341 329  
Service cost 19 20 16
Interest cost 7 6 9
Actuarial (gain) loss 35 (10)  
Benefits and expenses paid (11) (14)  
Effect of foreign exchange rate changes 5 10  
Benefit obligation, end of year 396 341 329
Plan assets:      
Fair value of plan assets, beginning of year 270 229  
Actual return on plan assets (9) 16  
Employer contributions 34 32  
Benefits and expenses paid (11) (14)  
Effect of foreign exchange rate changes 5 7  
Fair value of plan assets, end of year 289 270 229
Funded status of the plans [1] (107) (71)  
Amounts recognized in accumulated other comprehensive income:      
Net actuarial (gain) loss 95 44  
Prior service (credit) cost (2) (2)  
Total included in accumulated other comprehensive income 93 42  
Accumulated benefit obligation 356 307  
U.S. | Pension Plan      
Projected benefit obligation:      
Benefit obligation, beginning of year 908 798  
Service cost 27 24 23
Interest cost 31 40 29
Actuarial (gain) loss (69) 65  
Benefits and expenses paid (22) (19)  
Effect of foreign exchange rate changes 0 0  
Benefit obligation, end of year 875 908 798
Plan assets:      
Fair value of plan assets, beginning of year 448 359  
Actual return on plan assets (30) 61  
Employer contributions 69 47  
Benefits and expenses paid (22) (19)  
Effect of foreign exchange rate changes 0 0  
Fair value of plan assets, end of year 465 448 $ 359
Funded status of the plans [1] (410) (460)  
Amounts recognized in accumulated other comprehensive income:      
Net actuarial (gain) loss 174 203  
Prior service (credit) cost (4) (4)  
Total included in accumulated other comprehensive income 170 199  
Accumulated benefit obligation $ 746 $ 756  
[1] Recognized in other liabilities in the consolidated balance sheets
v3.10.0.1
BENEFIT PLANS - Weighted-Average Actuarial Assumptions (Detail)
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Other Postretirement Benefit Plans, Defined Benefit      
Weighted-average actuarial assumptions:      
Discount rate - net periodic benefit cost 3.75% 4.25% 4.50%
Discount rate - benefit obligations 4.25% 3.75% 4.25%
Health care cost trend rates [1] 7.40% 5.40% 5.20%
Defined benefit plan, ultimate health care cost trend rate 4.10% 4.50% 4.50%
Defined benefit plan number of years that rate reaches ultimate trend rate 61 years 77 years 74 years
Japan | Pension Plan      
Weighted-average actuarial assumptions:      
Discount rate - net periodic benefit cost 1.25% 1.25% 1.75%
Discount rate - benefit obligations 1.25% 1.25% 1.25%
Expected long-term return on plan assets 2.00% 2.00% 2.00%
U.S. | Pension Plan      
Weighted-average actuarial assumptions:      
Discount rate - net periodic benefit cost 3.75% 4.25% 4.50%
Discount rate - benefit obligations 4.25% 3.75% 4.25%
Expected long-term return on plan assets 6.50% 6.75% 7.00%
Rate of compensation increase 4.00% 4.00% 4.00%
[1] For the years 2018, 2017 and 2016, the health care cost trend rates are expected to trend down to 4.1% in 61 years, 4.5% in 77 years, and 4.5% in 74 years, respectively.
v3.10.0.1
BENEFIT PLANS - One-Percentage Point Increase and Decrease in Assumed Health Care Cost Trend Rates (Detail)
$ in Millions
 12 Months Ended
Dec. 31, 2018
USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]  
Increase in total service and interest costs $ 0
Increase in postretirement benefit obligation 1
Decrease in total service and interest costs 0
Decrease in postretirement benefit obligation $ 1
v3.10.0.1
BENEFIT PLANS - Net Periodic (Benefit) Cost Included in Acquisition and Operating Expenses (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Other Postretirement Benefit Plans, Defined Benefit      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Service cost $ 0 $ 0 $ 1
Interest cost 1 1 2
Expected return on plan assets 0 0 0
Amortization of net actuarial loss 1 1 1
Amortization of prior service cost (credit) 0 0 (11)
Net periodic (benefit) cost 2 2 (7)
Japan | Pension Plan      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Service cost 19 20 16
Interest cost 7 6 9
Expected return on plan assets (6) (5) (4)
Amortization of net actuarial loss 1 2 1
Amortization of prior service cost (credit) 0 0 0
Net periodic (benefit) cost 21 23 22
U.S. | Pension Plan      
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]      
Service cost 27 24 23
Interest cost 31 40 29
Expected return on plan assets (26) (24) (23)
Amortization of net actuarial loss 16 14 13
Amortization of prior service cost (credit) 0 0 0
Net periodic (benefit) cost $ 48 $ 54 $ 42
v3.10.0.1
BENEFIT PLANS - Summary of Amounts Recognized in Other Comprehensive Loss (Income) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Other Postretirement Benefit Plans, Defined Benefit      
Defined Benefit Plan Disclosure [Line Items]      
Net actuarial loss (gain) $ 4 $ 0 $ (4)
Amortization of net actuarial loss (1) (1) (1)
Amortization of prior service cost 0 0 11
Total 3 (1) 6
Japan | Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Net actuarial loss (gain) 52 (21) 26
Amortization of net actuarial loss (1) (2) (1)
Amortization of prior service cost 0 0 0
Total 51 (23) 25
U.S. | Pension Plan      
Defined Benefit Plan Disclosure [Line Items]      
Net actuarial loss (gain) (13) 28 27
Amortization of net actuarial loss (16) (14) (13)
Amortization of prior service cost 0 0 0
Total $ (29) $ 14 $ 14
v3.10.0.1
BENEFIT PLANS - Expected Benefit Payments (Detail)
$ in Millions
Dec. 31, 2018
USD ($)
Other Postretirement Benefit Plans, Defined Benefit  
Schedule of Postemployment Expected Future Benefit Payments [Line Items]  
2019 $ 3
2020 3
2021 4
2022 4
2023 4
2024-2028 17
Japan | Pension Plan  
Schedule of Postemployment Expected Future Benefit Payments [Line Items]  
2019 12
2020 12
2021 12
2022 19
2023 15
2024-2028 89
U.S. | Pension Plan  
Schedule of Postemployment Expected Future Benefit Payments [Line Items]  
2019 25
2020 26
2021 27
2022 36
2023 34
2024-2028 $ 199
v3.10.0.1
BENEFIT PLANS - Asset Allocation Targets (Detail) - Pension Plan
Dec. 31, 2018
Japan  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 100.00%
U.S.  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 100.00%
Domestic equity securities | Japan  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 5.00%
Domestic equity securities | U.S.  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 40.00%
International equity securities | Japan  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 18.00%
International equity securities | U.S.  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 20.00%
Fixed income bond funds | Japan  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 66.00%
Fixed income bond funds | U.S.  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 40.00%
Other Investments | Japan  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 11.00%
Other Investments | U.S.  
Defined Benefit Plan Disclosure [Line Items]  
Asset allocation targets 0.00%
v3.10.0.1
BENEFIT PLANS - Fair Value Hierarchy Levels of Funded Pension Plans' Assets (Detail) - Pension Plan - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Japan      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets $ 289 $ 270 $ 229
U.S.      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 465 448 $ 359
Japanese equity securities | Japan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 14 37  
International equity securities | Japan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 50 50  
Japanese bonds | Japan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 34 91  
International bonds | Japan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 160 62  
Insurance contracts | Japan | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 31 30  
U.S. large cap equity securities | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 120 124  
U.S. mid cap equity securities | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 17 22  
Real estate equity funds | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 13 13  
International equity funds | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 92 108  
Fixed income bond funds | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 179 175  
Aflac Incorporated common stock | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets 5 5  
Cash and cash equivalents | U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Fair value of pension plan assets $ 39 $ 1  
v3.10.0.1
COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Detail)
$ in Millions, ¥ in Billions
 3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Dec. 31, 2018
USD ($)
agreements
Dec. 31, 2018
JPY (¥)
agreements
Dec. 31, 2017
Commitments and Contingencies Disclosure [Line Items]        
Number of operating service agreements, technology and consulting | agreements   2 2  
Number of operating service agreements, management consulting and technology | agreements   1 1  
Number of operating service agreements, information technology and data services | agreements   2 2  
Operating Leases, lease terms   expire in various years through 2028 expire in various years through 2028  
Loss contingency accrual, insurance-related assessment, discount rate 4.25%      
Loss contingency, discounted amount of insurance-related assessment liability $ 62      
Loss contingency, undiscounted amount of insurance-related assessment liability 94      
Loss contingency, insurance related assessment, discounted amount of premium tax offset 48      
Loss contingency, insurance-related assessment, undiscounted amount of premium tax offset 74      
Loss contingency, discounted amount of insurance-related assessment liability, realization period for associated asset offsets (in years)       4
Loss contingency, loss in period $ 14      
Mainframe and server computer operations and support        
Commitments and Contingencies Disclosure [Line Items]        
Outsourcing agreements, remaining term   4 years 4 years  
Outsourcing agreements, aggregate remaining cost   $ 326 ¥ 36.1  
Technology and consulting company application maintenance and development services        
Commitments and Contingencies Disclosure [Line Items]        
Outsourcing agreements, remaining term   5 years 5 years  
Outsourcing agreements, aggregate remaining cost   $ 77 ¥ 8.6  
Management consulting and technology services company application maintenance and development services        
Commitments and Contingencies Disclosure [Line Items]        
Outsourcing agreements, remaining term   3 years 3 years  
Outsourcing agreements, aggregate remaining cost   $ 94 ¥ 10.4  
Information technology and data services company application maintenance and development services first agreement        
Commitments and Contingencies Disclosure [Line Items]        
Outsourcing agreements, remaining term   1 year 1 year  
Outsourcing agreements, aggregate remaining cost   $ 5 ¥ 0.6  
Information technology and data services company application maintenance and development services second agreement        
Commitments and Contingencies Disclosure [Line Items]        
Outsourcing agreements, remaining term   4 years 4 years  
Outsourcing agreements, aggregate remaining cost   $ 52 ¥ 5.8  
v3.10.0.1
COMMITMENTS AND CONTINGENT LIABILITIES - Future Minimum Lease Payments due under Non-Cancelable Operating Leases (Detail)
$ in Millions
Dec. 31, 2018
USD ($)
Commitments and Contingencies Disclosure [Abstract]  
2019 $ 63
2020 47
2021 35
2022 31
2023 8
Thereafter 18
Total future minimum lease payments $ 202
v3.10.0.1
Unaudited Consolidated Quarterly Financial Data (Detail) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Condensed Income Statements, [Line Items]                      
Net premium income $ 4,591 $ 4,636 $ 4,706 $ 4,745 $ 4,580 $ 4,648 $ 4,665 $ 4,638 $ 18,677 $ 18,531 $ 19,225
Net investment income 874 870 862 837 812 811 802 794 3,442 3,220 3,278
Realized investment gains (losses) (355) 56 3 (134) 15 30 (56) (140)      
Other income (loss) 16 15 18 16 17 17 17 17 69 67 70
Total revenues 5,126 5,577 5,589 5,464 5,424 5,506 5,428 5,309 21,758 21,667 22,559
Total benefits and expenses 4,404 4,431 4,458 4,482 4,425 4,431 4,383 4,411 17,775 17,649 18,492
Earnings before income taxes 722 1,146 1,131 982 999 1,075 1,045 898 3,983 4,018 4,067
Total income tax expense 197 301 299 265 (1,585) 359 332 306 $ 1,063 $ (586) $ 1,408
Net earnings $ 525 $ 845 $ 832 $ 717 $ 2,584 $ 716 $ 713 $ 592      
Net earnings per basic share $ 0.69 $ 1.10 $ 1.08 $ 0.92 $ 3.29 $ 0.91 $ 0.90 $ 0.74 $ 3.79 $ 5.81 $ 3.23
Net earnings per diluted share $ 0.69 $ 1.09 $ 1.07 $ 0.91 $ 3.27 $ 0.90 $ 0.89 $ 0.73 $ 3.77 $ 5.77 $ 3.21
Parent Company                      
Condensed Income Statements, [Line Items]                      
Net investment income                 $ 69 $ 30 $ 18
Total revenues                 247 331 213
Total income tax expense                 $ (12) $ (23) $ (102)
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Condensed Statement of Earnings (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Condensed Income Statements, [Line Items]                      
Net investment income $ 874 $ 870 $ 862 $ 837 $ 812 $ 811 $ 802 $ 794 $ 3,442 $ 3,220 $ 3,278
Realized investment gains (losses)                 (430) (151) (14)
Other income (loss) 16 15 18 16 17 17 17 17 69 67 70
Total revenues 5,126 5,577 5,589 5,464 5,424 5,506 5,428 5,309 21,758 21,667 22,559
Interest expense                 222 240 268
Current tax expense (benefit)                 1,379 631 884
Deferred tax expense (benefit)                 (316) (1,217) 524
Income tax expense (benefit) $ 197 $ 301 $ 299 $ 265 $ (1,585) $ 359 $ 332 $ 306 1,063 (586) 1,408
Net earnings                 2,920 4,604 2,659
Parent Company                      
Condensed Income Statements, [Line Items]                      
Management and service fees from subsidiaries [1]                 190 297 265
Net investment income                 69 30 18
Interest from subsidiaries [1]                 4 5 5
Realized investment gains (losses)                 90 67 84
Change in fair value on the cross-currency interest rate swaps                 (106) (68) (159)
Total revenues                 247 331 213
Interest expense                 188 197 213
Other operating expenses [2]                 225 180 277
Total operating expenses                 413 377 490
Earnings before income taxes and equity in earnings of subsidiaries                 (166) (46) (277)
Income tax expense (benefit)                 (12) (23) (102)
Earnings before equity in earnings of subsidiaries                 (154) (23) (175)
Equity in earnings of subsidiaries [1]                 3,074 4,627 2,834
Net earnings                 $ 2,920 4,604 2,659
5.50% subordinated notes due September 2052                      
Condensed Income Statements, [Line Items]                      
Expense on extinguishment of debt                   $ 13  
Senior Notes due 2039 and 2040                      
Condensed Income Statements, [Line Items]                      
Expense on extinguishment of debt                     $ 137
[1] Eliminated in consolidation
[2] Includes expense of $13 in 2017 and $137 in 2016 for the early extinguishment of debt
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Condensed Statements of Comprehensive Income (Loss) (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]      
Net earnings $ 2,920 $ 4,604 $ 2,659
Other comprehensive income (loss) before income taxes:      
Unrealized foreign currency translation gains (losses) during period 232 286 283
Unrealized gains (losses) on derivatives during period 2 1 3
Pension liability adjustment during period (25) 9 (45)
Total other comprehensive income (loss) before income taxes (2,900) 2,029 3,040
Income tax expense (benefit) related to items of other comprehensive income (loss) (797) 631 1,035
Other comprehensive income (loss), net of tax [1] (2,103) 1,398 2,005
Total comprehensive income (loss) 817 6,002 4,664
Parent Company      
Condensed Financial Statements, Captions [Line Items]      
Net earnings 2,920 4,604 2,659
Other comprehensive income (loss) before income taxes:      
Unrealized foreign currency translation gains (losses) during period 232 286 283
Unrealized gains (losses) on fixed maturity securities during period [2] (3,109) 1,733 2,799
Unrealized gains (losses) on derivatives during period 2 1 3
Pension liability adjustment during period (25) 9 (45)
Total other comprehensive income (loss) before income taxes (2,900) 2,029 3,040
Income tax expense (benefit) related to items of other comprehensive income (loss) (797) 631 1,035
Other comprehensive income (loss), net of tax (2,103) 1,398 2,005
Total comprehensive income (loss) $ 817 $ 6,002 $ 4,664
[1] All amounts in the table above are net of tax.
[2] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail 1) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Investments and cash:        
Fixed maturity securities available for sale, at fair value (amortized cost $1,209 in 2018 and $1,163 in 2017) [2],[3] $ 82,895 [1],[4] $ 84,313 [5]    
Other investments [6] 7,706 3,402    
Cash and cash equivalents 4,337 3,491 $ 4,859 $ 4,350
Total investments and cash 126,243 123,659    
Other assets [7] 2,221 2,023    
Total assets 140,406 137,217    
Liabilities:        
Notes payable 5,765 5,267    
Other liabilities [8] 2,906 2,832    
Total liabilities 116,944 112,619    
Shareholders' equity:        
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2018 and 2017; issued 1,347,540 shares in 2018 and 1,345,762 shares in 2017 135 135    
Additional paid-in capital 2,177 2,052    
Retained earnings 31,788 29,895    
Accumulated other comprehensive income (loss):        
Unrealized foreign currency translation gains (losses) (1,847) (1,750)    
Unrealized gains (losses) on fixed maturity securities [9] 4,234 5,964    
Unrealized gains (losses) on derivatives (24) (23)    
Pension liability adjustment (212) (163)    
Treasury stock, at average cost (12,789) (11,512)    
Total shareholders' equity 23,462 24,598 20,482  
Total liabilities and shareholders' equity 140,406 137,217    
Parent Company        
Investments and cash:        
Fixed maturity securities available for sale, at fair value (amortized cost $1,209 in 2018 and $1,163 in 2017) 1,222 1,213    
Investments in subsidiaries [10] 26,230 26,869    
Other investments 21 51    
Cash and cash equivalents 1,767 1,725 $ 2,037 $ 1,721
Total investments and cash 29,240 29,858    
Due from subsidiaries [10] 98 90    
Income taxes receivable 176 121    
Other assets 390 366    
Total assets 29,904 30,435    
Liabilities:        
Employee benefit plans 310 341    
Notes payable 5,765 5,267    
Other liabilities 367 229    
Total liabilities 6,442 5,837    
Shareholders' equity:        
Common stock of $.10 par value. In thousands: authorized 1,900,000 shares in 2018 and 2017; issued 1,347,540 shares in 2018 and 1,345,762 shares in 2017 135 135    
Additional paid-in capital 2,177 2,052    
Retained earnings 31,788 29,895    
Accumulated other comprehensive income (loss):        
Unrealized foreign currency translation gains (losses) (1,847) (1,750)    
Unrealized gains (losses) on fixed maturity securities [11] 4,234 5,964    
Unrealized gains (losses) on derivatives (24) (23)    
Pension liability adjustment (212) (163)    
Treasury stock, at average cost (12,789) (11,512)    
Total shareholders' equity 23,462 24,598    
Total liabilities and shareholders' equity $ 29,904 $ 30,435    
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities
[3] Includes perpetual securities
[4] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[5] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
[6] Includes $5,856 in 2018 and $2,341 in 2017 of loan receivables and limited partnerships from consolidated variable interest entities
[7] Includes $182 in 2018 and $151 in 2017 of derivatives from consolidated variable interest entities
[8] Includes $102 in 2018 and $128 in 2017 of derivatives from consolidated variable interest entities
[9] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
[10] Eliminated in consolidation
[11] See Note 1 of the Notes to the Consolidated Financial Statements for the adoption of accounting guidance on January 1, 2018 related to financial instruments.
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Condensed Balance Sheet (Detail 2) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]        
Available for sale, fixed maturity securities, amortized cost $ 76,856 [1],[2] $ 75,132 [3]    
Common stock, par value (in dollars per share) $ 0.10 $ 0.10    
Common stock, shares authorized (in shares) 1,900,000 1,900,000    
Common stock, shares issued (in shares) 1,347,540 1,345,762 1,342,498 1,339,446
Parent Company        
Condensed Financial Statements, Captions [Line Items]        
Available for sale, fixed maturity securities, amortized cost $ 1,209 $ 1,163    
Common stock, par value (in dollars per share) $ 0.10 $ 0.10    
Common stock, shares authorized (in shares) 1,900,000 1,900,000    
Common stock, shares issued (in shares) 1,347,540 1,345,762    
[1] Includes perpetual securities ($1,139 at amortized cost and $1,140 at fair value)
[2] Includes perpetual securities, categorized in accordance with their respective economic maturities (the expected maturity date created by the combination of features in the financial instrument)
[3] Includes perpetual securities ($1,462 at amortized cost and $1,789 at fair value)
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Condensed Statements of Cash Flows (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Cash flows from operating activities:      
Net earnings $ 2,920 $ 4,604 $ 2,659
Adjustments to reconcile net earnings to net cash provided from operating activities:      
Other, net 571 150 340 [1]
Net cash provided (used) by operating activities 6,014 6,128 5,987
Cash flows from investing activities:      
Fixed maturity securities purchased (9,086) (9,867) (10,890)
Other investments sold (purchased) (414) (206) (98)
Settlement of derivatives (241) (621) 1,252
Other, net 176 (68) (76)
Net cash provided (used) by investing activities (3,582) (5,431) (3,855)
Cash flows from financing activities:      
Purchases of treasury stock (1,301) (1,351) (1,422)
Proceeds from borrowings 1,020 1,040 986
Principal payments under debt obligations (550) (1,161) (610)
Dividends paid to shareholders (793) (661) (658)
Treasury stock reissued 58 33 46
Proceeds from exercise of stock options 48 58 68
Other, net (19) 0 (120) [1]
Net cash provided (used) by financing activities (1,616) (2,065) (1,619)
Net change in cash and cash equivalents 846 (1,368) 509
Cash and cash equivalents, beginning of period 3,491 4,859 4,350
Cash and cash equivalents, end of period 4,337 3,491 4,859
Parent Company      
Cash flows from operating activities:      
Net earnings 2,920 4,604 2,659
Adjustments to reconcile net earnings to net cash provided from operating activities:      
Equity in earnings of subsidiaries [2] (3,074) (4,627) (2,834)
Cash dividends received from subsidiaries 1,820 2,001 2,020
Other, net 99 (46) 294 [3]
Net cash provided (used) by operating activities 1,765 1,932 2,139
Cash flows from investing activities:      
Fixed maturity securities sold 207 263 225
Fixed maturity securities purchased (254) (329) (229)
Other investments sold (purchased) 31 (47) 6
Settlement of derivatives (2) 223 0
Additional capitalization of subsidiaries [2] (62) (69) (36)
Other, net (107) (218) (25)
Net cash provided (used) by investing activities (187) (177) (59)
Cash flows from financing activities:      
Purchases of treasury stock (1,301) (1,351) (1,422)
Proceeds from borrowings 1,020 1,040 986
Principal payments under debt obligations (550) (1,161) (621)
Dividends paid to shareholders (793) (661) (658)
Treasury stock reissued 58 33 46
Proceeds from exercise of stock options 34 38 36
Net change in amount due to/from subsidiary [2] (4) (5) (6)
Other, net 0 0 (125) [3]
Net cash provided (used) by financing activities (1,536) (2,067) (1,764)
Net change in cash and cash equivalents 42 (312) 316
Cash and cash equivalents, beginning of period 1,725 2,037 1,721
Cash and cash equivalents, end of period $ 1,767 $ 1,725 2,037
Senior Notes due 2039 and 2040      
Condensed Cash Flow Statements, Captions [Line Items]      
Expense on extinguishment of debt     $ 137
[1] Operating activities excludes and financing activities includes a cash outflow of $137 in 2016 for the payments associated with the early extinguishment of debt
[2] Eliminated in consolidation
[3] Operating activities excludes and financing activities includes a cash outflow of $137 in 2016 for the payment associated with the early extinguishment of debt
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Summary of Notes Payable (Detail 1) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Condensed Financial Statements, Captions [Line Items]    
Notes payable $ 5,765 $ 5,267
Parent Company    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 5,765 5,267
Parent Company | 2.40% senior notes paid November 2018    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 0 548
Parent Company | 4.00% senior notes due February 2022    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 348 348
Parent Company | 3.625% senior notes due June 2023    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 698 697
Parent Company | 3.625% senior notes due November 2024    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 746 745
Parent Company | 3.25% senior notes due March 2025    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 447 446
Parent Company | 2.875% senior notes due October 2026    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 297 297
Parent Company | 6.90% senior notes due December 2039    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 220 220
Parent Company | 6.45% senior notes due August 2040    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 254 254
Parent Company | 4.00% senior notes due October 2046    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 394 394
Parent Company | 4.750% senior notes due January 2049    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 540 0
Parent Company | .932% senior notes due January 2027    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 538 528
Parent Company | 1.159% senior notes due October 2030    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 262 0
Parent Company | 1.488% senior notes due October 2033    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 136 0
Parent Company | 1.750% senior notes due October 2038    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 79 0
Parent Company | 2.108% subordinated notes due October 2047    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 536 526
Parent Company | Yen-denominated loan variable interest rate due September 2021    
Condensed Financial Statements, Captions [Line Items]    
Notes payable 45 44
Parent Company | Yen-denominated loan variable interest rate due September 2023    
Condensed Financial Statements, Captions [Line Items]    
Notes payable $ 225 $ 220
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Summary of Notes Payable (Detail 2)
$ in Millions, ¥ in Billions
 1 Months Ended
Oct. 31, 2018
USD ($)
Oct. 31, 2017
JPY (¥)
Jan. 31, 2017
JPY (¥)
Sep. 30, 2016
USD ($)
Mar. 31, 2015
USD ($)
Nov. 30, 2014
USD ($)
Jun. 30, 2013
USD ($)
Feb. 29, 2012
USD ($)
Aug. 31, 2010
USD ($)
Dec. 31, 2009
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Nov. 30, 2018
USD ($)
Oct. 31, 2018
JPY (¥)
Dec. 31, 2017
USD ($)
Dec. 31, 2017
JPY (¥)
Dec. 31, 2016
Sep. 30, 2016
JPY (¥)
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 5,765       $ 5,267      
2.40% senior notes paid November 2018                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate         2.40%               2.40%   2.40% 2.40%    
Debt instrument, principal amount         $ 550               $ 550          
Debt instrument, term         5 years                          
4.00% senior notes due February 2022                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate               4.00%     4.00% 4.00%     4.00% 4.00%    
Debt instrument, principal amount               $ 350     $ 350              
Debt instrument, term               10 years                    
3.625% senior notes due June 2023                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate             3.625%       3.625% 3.625%     3.625% 3.625%    
Debt instrument, principal amount             $ 700       $ 700              
Debt instrument, term             10 years                      
3.625% senior notes due November 2024                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate           3.625%         3.625% 3.625%     3.625% 3.625%    
Debt instrument, principal amount           $ 750         $ 750              
Debt instrument, term           10 years                        
3.25% senior notes due March 2025                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate         3.25%           3.25% 3.25%     3.25% 3.25%    
Debt instrument, principal amount         $ 450           $ 450              
Debt instrument, term         10 years                          
2.875% senior notes due October 2026                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate       2.875%             2.875% 2.875%     2.875% 2.875%   2.875%
Debt instrument, principal amount       $ 300                            
Debt instrument, term       10 years                            
6.90% senior notes due December 2039                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate                     6.90% 6.90%     6.90% 6.90% 6.90%  
Debt instrument, principal amount                   $ 400                
Debt instrument, term                   30 years                
6.45% senior notes due August 2040                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate                     6.45% 6.45%     6.45% 6.45% 6.45%  
Debt instrument, principal amount                 $ 450                  
Debt instrument, term                 30 years                  
4.00% senior notes due October 2046                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate       4.00%             4.00% 4.00%     4.00% 4.00%   4.00%
Debt instrument, principal amount       $ 400                            
Debt instrument, term       30 years                            
4.750% senior notes due January 2049                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate 4.75%                   4.75% 4.75%   4.75%        
Debt instrument, principal amount $ 550                                  
Debt instrument, term 30 years                                  
.932% senior notes due January 2027                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate     0.932%               0.932% 0.932%     0.932% 0.932%    
Debt instrument, principal amount | ¥     ¥ 60.0                 ¥ 60.0       ¥ 60.0    
Debt instrument, term     10 years                              
1.159% senior notes due October 2030                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate 1.159%                   1.159% 1.159%   1.159%        
Debt instrument, principal amount | ¥                       ¥ 29.3   ¥ 29.3        
Debt instrument, term 12 years                                  
1.488% senior notes due October 2033                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate 1.488%                   1.488% 1.488%   1.488%        
Debt instrument, principal amount | ¥                       ¥ 15.2   ¥ 15.2        
Debt instrument, term 15 years                                  
1.750% senior notes due October 2038                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate 1.75%                   1.75% 1.75%   1.75%        
Debt instrument, principal amount | ¥                       ¥ 8.9   ¥ 8.9        
Debt instrument, term 20 years                                  
2.108% subordinated notes due October 2047                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate   2.108%                 2.108% 2.108%     2.108% 2.108%    
Debt instrument, principal amount | ¥   ¥ 60.0                   ¥ 60.0       ¥ 60.0    
Debt instrument, term   30 years                                
Yen-denominated loan variable interest rate due September 2021                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate                     0.32% 0.32%     0.32% 0.32%    
Debt instrument, principal amount | ¥                       ¥ 5.0       ¥ 5.0   ¥ 5.0
Debt instrument, term       5 years                            
Yen-denominated loan variable interest rate due September 2023                                    
Condensed Financial Statements, Captions [Line Items]                                    
Debt instrument, interest rate                     0.47% 0.47%     0.47% 0.47%    
Debt instrument, principal amount | ¥                       ¥ 25.0       ¥ 25.0   ¥ 25.0
Debt instrument, term       7 years                            
Parent Company                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 5,765       $ 5,267      
Parent Company | 2.40% senior notes paid November 2018                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     0       $ 548      
Debt instrument, interest rate                         2.40%   2.40% 2.40%    
Debt instrument, principal amount                         $ 550          
Parent Company | 4.00% senior notes due February 2022                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 348       $ 348      
Debt instrument, interest rate                     4.00% 4.00%     4.00% 4.00%    
Parent Company | 3.625% senior notes due June 2023                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 698       $ 697      
Debt instrument, interest rate                     3.625% 3.625%     3.625% 3.625%    
Parent Company | 3.625% senior notes due November 2024                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 746       $ 745      
Debt instrument, interest rate                     3.625% 3.625%     3.625% 3.625%    
Parent Company | 3.25% senior notes due March 2025                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 447       $ 446      
Debt instrument, interest rate                     3.25% 3.25%     3.25% 3.25%    
Parent Company | 2.875% senior notes due October 2026                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 297       $ 297      
Debt instrument, interest rate                     2.875% 2.875%     2.875% 2.875%    
Parent Company | 6.90% senior notes due December 2039                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 220       $ 220      
Debt instrument, interest rate                     6.90% 6.90%     6.90% 6.90%    
Parent Company | 6.45% senior notes due August 2040                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 254       $ 254      
Debt instrument, interest rate                     6.45% 6.45%     6.45% 6.45%    
Parent Company | 4.00% senior notes due October 2046                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 394       $ 394      
Debt instrument, interest rate                     4.00% 4.00%     4.00% 4.00%    
Parent Company | 4.750% senior notes due January 2049                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 540       $ 0      
Debt instrument, interest rate 4.75%                   4.75% 4.75%   4.75%        
Debt instrument, term 30 years                                  
Parent Company | .932% senior notes due January 2027                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 538       $ 528      
Debt instrument, interest rate                     0.932% 0.932%     0.932% 0.932%    
Debt instrument, principal amount | ¥                       ¥ 60.0       ¥ 60.0    
Parent Company | 1.159% senior notes due October 2030                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 262       $ 0      
Debt instrument, interest rate 1.159%                   1.159% 1.159%   1.159%        
Debt instrument, principal amount | ¥                       ¥ 29.3   ¥ 29.3        
Debt instrument, term 12 years                                  
Parent Company | 1.488% senior notes due October 2033                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 136       0      
Debt instrument, interest rate 1.488%                   1.488% 1.488%   1.488%        
Debt instrument, principal amount | ¥                       ¥ 15.2   ¥ 15.2        
Debt instrument, term 15 years                                  
Parent Company | 1.750% senior notes due October 2038                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 79       0      
Debt instrument, interest rate 1.75%                   1.75% 1.75%   1.75%        
Debt instrument, principal amount | ¥                       ¥ 8.9   ¥ 8.9        
Debt instrument, term 20 years                                  
Parent Company | 2.108% subordinated notes due October 2047                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 536       $ 526      
Debt instrument, interest rate                     2.108% 2.108%     2.108% 2.108%    
Debt instrument, principal amount | ¥                       ¥ 60.0       ¥ 60.0    
Parent Company | Yen-denominated loan variable interest rate due September 2021                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 45       $ 44      
Debt instrument, interest rate                     0.32% 0.32%     0.32% 0.32%    
Debt instrument, principal amount | ¥                       ¥ 5.0       ¥ 5.0    
Parent Company | Yen-denominated loan variable interest rate due September 2023                                    
Condensed Financial Statements, Captions [Line Items]                                    
Notes payable                     $ 225       $ 220      
Debt instrument, interest rate                     0.47% 0.47%     0.47% 0.47%    
Debt instrument, principal amount | ¥                       ¥ 25.0       ¥ 25.0    
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Additional Information (Detail)
$ in Millions, ¥ in Billions
 1 Months Ended
Oct. 31, 2018
USD ($)
series
Mar. 31, 2015
USD ($)
series
Dec. 31, 2018
USD ($)
Dec. 31, 2018
JPY (¥)
Nov. 30, 2018
USD ($)
Oct. 31, 2018
JPY (¥)
series
Dec. 31, 2017
USD ($)
Sep. 30, 2016
USD ($)
series
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 5,778       $ 5,289  
Number of series of senior notes issued through a U.S. public debt offering (in series) | series 3 2       3   2
4.750% senior notes due January 2049                
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 540       0  
Debt Instrument, Face Amount $ 550              
Debt Instrument, Interest Rate, Stated Percentage 4.75%   4.75% 4.75%   4.75%    
Debt instrument, term 30 years              
Debt instrument, redemption, description These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.              
2.40% senior notes paid November 2018                
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 0       $ 548  
Debt Instrument, Face Amount   $ 550     $ 550      
Debt Instrument, Interest Rate, Stated Percentage   2.40%     2.40%   2.40%  
Debt instrument, term   5 years            
Senior Notes                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount   $ 1,000       ¥ 53.4   $ 700
1.159% senior notes due October 2030                
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 262       $ 0  
Debt Instrument, Face Amount | ¥       ¥ 29.3   ¥ 29.3    
Debt Instrument, Interest Rate, Stated Percentage 1.159%   1.159% 1.159%   1.159%    
Debt instrument, term 12 years              
1.488% senior notes due October 2033                
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 136       0  
Debt Instrument, Face Amount | ¥       ¥ 15.2   ¥ 15.2    
Debt Instrument, Interest Rate, Stated Percentage 1.488%   1.488% 1.488%   1.488%    
Debt instrument, term 15 years              
1.750% senior notes due October 2038                
Condensed Financial Statements, Captions [Line Items]                
Notes payable     $ 79       $ 0  
Debt Instrument, Face Amount | ¥       ¥ 8.9   ¥ 8.9    
Debt Instrument, Interest Rate, Stated Percentage 1.75%   1.75% 1.75%   1.75%    
Debt instrument, term 20 years              
Parent Company                
Condensed Financial Statements, Captions [Line Items]                
Number of series of senior notes issued through a U.S. public debt offering (in series) | series 3         3    
Parent Company | 4.750% senior notes due January 2049                
Condensed Financial Statements, Captions [Line Items]                
Notes payable $ 550              
Debt Instrument, Interest Rate, Stated Percentage 4.75%   4.75% 4.75%   4.75%    
Debt instrument, term 30 years              
Debt instrument, redemption, description These notes are redeemable at the Parent Company's option in whole at any time or in part from time to time at a redemption price equal to the greater of: (i) the aggregate principal amount of the notes to be redeemed or (ii) the amount equal to the sum of the present values of the remaining scheduled payments for principal of and interest on the notes to be redeemed, not including any portion of the payments of interest accrued as of such redemption date, discounted to such redemption date on a semiannual basis at the yield to maturity for a United States Treasury security with a maturity comparable to the remaining term of the notes, plus 25 basis points, plus in each case, accrued and unpaid interest on the principal amount of the notes to be redeemed to, but excluding, such redemption date.              
Parent Company | 2.40% senior notes paid November 2018                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount         $ 550      
Debt Instrument, Interest Rate, Stated Percentage         2.40%   2.40%  
Parent Company | Senior Notes                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount | ¥           ¥ 53.4    
Parent Company | 1.159% senior notes due October 2030                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount | ¥       ¥ 29.3   ¥ 29.3    
Debt Instrument, Interest Rate, Stated Percentage 1.159%   1.159% 1.159%   1.159%    
Debt instrument, term 12 years              
Parent Company | 1.488% senior notes due October 2033                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount | ¥       ¥ 15.2   ¥ 15.2    
Debt Instrument, Interest Rate, Stated Percentage 1.488%   1.488% 1.488%   1.488%    
Debt instrument, term 15 years              
Parent Company | 1.750% senior notes due October 2038                
Condensed Financial Statements, Captions [Line Items]                
Debt Instrument, Face Amount | ¥       ¥ 8.9   ¥ 8.9    
Debt Instrument, Interest Rate, Stated Percentage 1.75%   1.75% 1.75%   1.75%    
Debt instrument, term 20 years              
v3.10.0.1
Schedule II - Aflac Incorporated - Aggregate Contractual Maturities of Notes Payable (Detail)
$ in Millions
Dec. 31, 2018
USD ($)
Condensed Financial Statements, Captions [Line Items]  
2019 $ 5
2020 3
2021 47
2022 351
2023 926
Thereafter 4,494
Total 5,826
Parent Company  
Condensed Financial Statements, Captions [Line Items]  
2019 0
2020 0
2021 45
2022 350
2023 925
Thereafter 4,493
Total $ 5,813
v3.10.0.1
Schedule II - Aflac Incorporated (Parent Only) - Supplemental Disclosure of Cash Flow Information (Detail) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]      
Interest paid $ 181 $ 196 $ 211
Shareholder dividend reinvestment      
Condensed Cash Flow Statements, Captions [Line Items]      
Treasury stock issued for shareholder dividend reinvestment 8 29 27
Parent Company      
Condensed Cash Flow Statements, Captions [Line Items]      
Interest paid 179 195 209
Parent Company | Shareholder dividend reinvestment      
Condensed Cash Flow Statements, Captions [Line Items]      
Treasury stock issued for shareholder dividend reinvestment $ 8 $ 29 $ 26
v3.10.0.1
SCHEDULE III SUPPLEMENTARY INSURANCE INFORMATION - (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]                      
Deferred policy acquisition costs $ 9,875       $ 9,505       $ 9,875 $ 9,505  
Future policy benefits & unpaid policy claims 90,952       86,249       90,952 86,249  
Unearned premiums 5,090       5,959       5,090 5,959  
Other policyholders' funds 7,146       6,939       7,146 6,939  
Premiums Earned, Net 4,591 $ 4,636 $ 4,706 $ 4,745 4,580 $ 4,648 $ 4,665 $ 4,638 18,677 18,531 $ 19,225
Net investment income 874 $ 870 $ 862 $ 837 812 $ 811 $ 802 $ 794 3,442 3,220 3,278
Benefits and claims, net                 12,000 12,181 12,919
Amortization of deferred policy acquisition costs                 1,245 1,132 1,141
Other operating expenses                 4,530 4,336 4,432
Premiums written                 18,005 17,657 18,214
Aflac Japan                      
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]                      
Deferred policy acquisition costs 6,384       6,150       6,384 6,150 5,765
Future policy benefits & unpaid policy claims 80,672       76,353       80,672 76,353  
Unearned premiums 4,977       5,840       4,977 5,840  
Other policyholders' funds 7,145       6,939       7,145 6,939  
Premiums Earned, Net                 12,762 12,752 13,537
Net investment income                 2,639 2,463 2,554
Benefits and claims, net                 8,913 9,087 9,828
Amortization of deferred policy acquisition costs                 710 630 644
Other operating expenses                 2,374 2,257 2,326
Premiums written                 12,298 12,092 12,762
Aflac U.S.                      
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]                      
Deferred policy acquisition costs 3,491       3,355       3,491 3,355 3,228
Future policy benefits & unpaid policy claims 10,864       10,506       10,864 10,506  
Unearned premiums 117       119       117 119  
Other policyholders' funds 0       0       0 0  
Premiums Earned, Net                 5,708 5,563 5,454
Net investment income                 727 721 703
Benefits and claims, net                 2,887 2,885 2,869
Amortization of deferred policy acquisition costs                 534 502 497
Other operating expenses                 1,736 1,658 1,593
Premiums written                 5,707 5,565 5,452
All other                      
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]                      
Deferred policy acquisition costs 0       0       0 0  
Future policy benefits & unpaid policy claims 183       138       183 138  
Unearned premiums 0       0       0 0  
Other policyholders' funds 1       0       1 0  
Premiums Earned, Net                 207 216 234
Net investment income                 76 36 21
Benefits and claims, net                 200 209 222
Amortization of deferred policy acquisition costs                 1 0 0
Other operating expenses                 420 421 513
Premiums written                 0 0 $ 0
Intercompany eliminations                      
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Line Items]                      
Deferred policy acquisition costs 0       0       0 0  
Future policy benefits & unpaid policy claims (767)       (748)       (767) (748)  
Unearned premiums (4)       0       (4) 0  
Other policyholders' funds $ 0       $ 0       $ 0 $ 0  
v3.10.0.1
SCHEDULE IV REINSURANCE Schedule IV - Reinsurance (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]                      
Gross Amount, Life Insurance in Force $ 151,457       $ 152,502       $ 151,457 $ 152,502 $ 151,093
Ceded to Other Companies, Life Insurance in Force 4,702       4,121       4,702 4,121 3,741
Assumed from Other Companies, Life Insurance in Force 0       0       0 0 0
Net Amount, Life Insurance in Force $ 146,755       $ 148,381       $ 146,755 $ 148,381 $ 147,352
Percentage of Amount Assumed to Net, Life Insurance in Force 0.00%       0.00%       0.00% 0.00% 0.00%
Gross amount                 $ 19,018 $ 18,875 $ 19,592
Ceded to Other Companies                 555 566 608
Assumed from Other companies                 214 222 241
Net Amount $ 4,591 $ 4,636 $ 4,706 $ 4,745 $ 4,580 $ 4,648 $ 4,665 $ 4,638 $ 18,677 $ 18,531 $ 19,225
Percentage of Amount Assumed to Net                 1.00% 1.00% 1.00%
Health insurance                      
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]                      
Gross amount                 $ 15,330 $ 14,829 $ 14,839
Ceded to Other Companies                 541 554 595
Assumed from Other companies                 214 222 241
Net Amount                 $ 15,003 $ 14,497 $ 14,485
Percentage of Amount Assumed to Net                 1.00% 1.00% 1.00%
Life insurance                      
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]                      
Gross amount                 $ 3,688 $ 4,046 $ 4,753
Ceded to Other Companies                 14 12 13
Assumed from Other companies                 0 0 0
Net Amount                 $ 3,674 $ 4,034 $ 4,740
Percentage of Amount Assumed to Net                 0.00% 0.00% 0.00%