DELTA AIR LINES, INC., 10-K filed on 2/12/2024
Annual Report
v3.24.0.1
Cover - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2023
Jan. 31, 2024
Jun. 30, 2023
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2023    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-5424    
Entity Registrant Name DELTA AIR LINES, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 58-0218548    
Entity Address, Address Line One Post Office Box 20706    
Entity Address, City or Town Atlanta    
Entity Address, State or Province GA    
Entity Address, Postal Zip Code 30320-6001    
City Area Code 404    
Local Phone Number 715-2600    
Title of 12(b) Security Common Stock, par value $0.0001 per share    
Trading Symbol DAL    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 30.4
Entity Common Stock, Shares Outstanding   643,323,851  
Documents Incorporated by Reference Part III of this Form 10-K incorporates by reference certain information from the registrant's definitive Proxy Statement for its 2024 Annual Meeting of Stockholders to be filed with the Securities and Exchange Commission.    
Entity Central Index Key 0000027904    
Document Fiscal Year Focus 2023    
Document Fiscal Period Focus FY    
Amendment Flag false    
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Audit Information
 12 Months Ended
Dec. 31, 2023
Audit Information [Abstract]  
Auditor Name Ernst & Young LLP
Auditor Location Atlanta, Georgia
Auditor Firm ID 42
v3.24.0.1
Consolidated Balance Sheets - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Current Assets:    
Cash and cash equivalents $ 2,741 $ 3,266
Short-term investments 1,127 3,268
Accounts receivable, net of an allowance for uncollectible accounts of $17 and $23 3,130 3,176
Fuel, expendable parts and supplies inventories, net of an allowance for obsolescence of $123 and $136 1,314 1,424
Prepaid expenses and other 1,957 1,877
Total current assets 10,269 13,011
Noncurrent Assets:    
Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370 35,486 33,109
Operating lease right-of-use assets 7,004 7,036
Goodwill 9,753 9,753
Identifiable intangibles, net of accumulated amortization of $911 and $902 5,983 5,992
Equity investments 3,457 2,128
Other noncurrent assets 1,692 1,259
Total noncurrent assets 63,375 59,277
Total assets 73,644 72,288
Current Liabilities:    
Current maturities of debt and finance leases 2,983 2,359
Current maturities of operating leases 759 714
Accounts payable 4,446 5,106
Accrued salaries and related benefits 4,561 3,288
Fuel card obligation 1,100 1,100
Other accrued liabilities 1,617 1,779
Total current liabilities 26,418 25,940
Noncurrent Liabilities:    
Debt and finance leases 17,071 20,671
Pension, postretirement and related benefits 3,601 3,707
Noncurrent operating leases 6,468 6,866
Deferred income taxes, net 908 24
Other noncurrent liabilities 3,561 4,050
Total noncurrent liabilities 36,121 39,766
Commitments and Contingencies
Stockholders' Equity:    
Common stock at $0.0001 par value; 1,500,000,000 shares authorized, 654,671,194 and 651,800,786 shares issued 0 0
Additional paid-in capital 11,641 11,526
Retained earnings 5,650 1,170
Accumulated other comprehensive loss (5,845) (5,801)
Treasury stock, at cost, 11,224,246 and 10,535,033 shares (341) (313)
Total stockholders' equity 11,105 6,582
Total liabilities and stockholders' equity 73,644 72,288
Air traffic    
Current Liabilities:    
Deferred revenue liability, current 7,044 8,160
Noncurrent Liabilities:    
Loyalty program deferred revenue   100
Loyalty program    
Current Liabilities:    
Deferred revenue liability, current 3,908 3,434
Noncurrent Liabilities:    
Loyalty program deferred revenue $ 4,512 $ 4,448
v3.24.0.1
Consolidated Balance Sheets (Parenthetical) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Current Assets:    
Allowance for uncollectible accounts $ 17 $ 23
Allowance for obsolescence 123 136
Noncurrent Assets:    
Accumulated depreciation and amortization 21,707 20,370
Accumulated amortization $ 911 $ 902
Stockholders' Equity:    
Common stock, par value (USD per share) $ 0.0001 $ 0.0001
Common stock, authorized (shares) 1,500,000,000 1,500,000,000
Common stock, issued (shares) 654,671,194 651,800,786
Treasury stock, at cost (shares) 11,224,246 10,535,033
v3.24.0.1
Consolidated Statements of Operations - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Operating Revenue:      
Total operating revenue $ 58,048 $ 50,582 $ 29,899
Operating Expense:      
Salaries and related costs 14,607 11,902 9,728
Aircraft fuel and related taxes 11,069 11,482 5,633
Ancillary businesses and refinery 4,172 5,756 3,957
Contracted services 4,041 3,345 2,420
Landing fees and other rents 2,563 2,181 2,019
Aircraft maintenance materials and outside repairs 2,432 1,982 1,401
Depreciation and amortization 2,341 2,107 1,998
Passenger commissions and other selling expenses 2,334 1,891 953
Regional carrier expense 2,200 2,051 1,736
Passenger service 1,750 1,453 756
Profit sharing 1,383 563 108
Pilot agreement and related expenses 864 0 0
Aircraft rent 532 508 430
Government grant recognition 0 0 (4,512)
Other 2,239 1,700 1,386
Total operating expense 52,527 46,921 28,013
Operating Income 5,521 3,661 1,886
Non-Operating Income/(Expense):      
Interest expense, net (834) (1,029) (1,279)
Gain/(loss) on investments, net 1,263 (783) 56
Loss on extinguishment of debt (63) (100) (319)
Pension and related (expense)/benefit (244) 292 451
Miscellaneous, net (35) (127) (397)
Total non-operating income/(expense), net 87 (1,747) (1,488)
Income Before Income Taxes 5,608 1,914 398
Income Tax Provision (999) (596) (118)
Net Income $ 4,609 $ 1,318 $ 280
Basic Earnings Per Share (USD per share) $ 7.21 $ 2.07 $ 0.44
Diluted Earnings Per Share (USD per share) $ 7.17 $ 2.06 $ 0.44
Passenger      
Operating Revenue:      
Total operating revenue $ 48,909 $ 40,218 $ 22,519
Cargo      
Operating Revenue:      
Total operating revenue 723 1,050 1,032
Other      
Operating Revenue:      
Total operating revenue $ 8,416 $ 9,314 $ 6,348
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Consolidated Statements of Comprehensive Income/(Loss) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Statement of Comprehensive Income [Abstract]      
Net Income $ 4,609 $ 1,318 $ 280
Other comprehensive income:      
Net change in pension and other benefits (44) 1,329 1,908
Total Other Comprehensive (Loss)/Income (44) 1,329 1,908
Comprehensive Income $ 4,565 $ 2,647 $ 2,188
v3.24.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Cash Flows From Operating Activities:      
Net income $ 4,609 $ 1,318 $ 280
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation and amortization 2,341 2,107 1,998
Deferred income taxes 980 591 115
(Gain)/loss on fair value investments (1,283) 874 (38)
Pension, postretirement and postemployment payments greater than expense (121) (453) (2,038)
Changes in certain assets and liabilities:      
Receivables (7) (728) (981)
Fuel inventory 121 (158) (318)
Prepaids and other current assets 17 (867) (58)
Profit sharing 821 455 108
Other payables, deferred revenue and accrued liabilities (285) 1,226 1,986
Noncurrent liabilities (18) (348) (399)
Other, net (33) 120 419
Net cash provided by operating activities 6,464 6,363 3,264
Property and equipment additions:      
Flight equipment, including advance payments (3,645) (4,495) (1,596)
Ground property and equipment, including technology (1,678) (1,871) (1,651)
Purchase of equity investments (152) (870) 0
Purchase of short-term investments (2,312) (2,704) (12,655)
Redemption of short-term investments 4,547 2,804 15,036
Other, net 92 212 (32)
Net cash used in investing activities (3,148) (6,924) (898)
Cash Flows From Financing Activities:      
Proceeds from long-term obligations 878 0 1,902
Payments on debt and finance lease obligations (4,071) (4,475) (5,834)
Cash dividends (128) 0 0
Other, net (73) (60) 80
Net cash used in financing activities (3,394) (4,535) (3,852)
Net Decrease in Cash, Cash Equivalents and Restricted Cash (78) (5,096) (1,486)
Cash, cash equivalents and restricted cash at beginning of period 3,473 8,569 10,055
Cash, cash equivalents and restricted cash at end of period 3,395 3,473 8,569
Supplemental Disclosure of Cash Paid for Interest 1,164 1,261 1,524
Non-Cash Transactions:      
Right-of-use assets acquired under operating leases 661 531 2,113
Flight and ground equipment acquired under finance leases 31 91 1,049
Operating leases converted to finance leases 84 342 42
Equity investments and other financings 0 330 0
Air traffic      
Changes in certain assets and liabilities:      
Liabilities and deferred revenue (1,216) 1,902 1,814
Loyalty program      
Changes in certain assets and liabilities:      
Liabilities and deferred revenue $ 538 $ 324 $ 376
v3.24.0.1
Consolidated Statements of Stockholders' Equity - USD ($)
$ in Millions
Total
Common Stock
Additional Paid-In Capital
Retained Earnings / (Accumulated Deficit)
Accumulated Other Comprehensive Loss
Treasury Stock
Beginning balance (in shares) at Dec. 31, 2020   647,000,000        
Beginning balance at Dec. 31, 2020 $ 1,534 $ 0 $ 11,259 $ (428) $ (9,038) $ (259)
Beginning balance, treasury (in shares) at Dec. 31, 2020           9,000,000
Consolidated Statements of Stockholders' Equity            
Net income 280     280    
Other comprehensive income (loss) 1,908       1,908  
Common stock issued for employee equity awards (shares) [1]   3,000,000       1,000,000
Common stock issued for employee equity awards [1] 79   102     $ (23)
Government grant warrant issuance 86   86      
Ending balance (in shares) at Dec. 31, 2021   650,000,000        
Ending balance at Dec. 31, 2021 3,887 $ 0 11,447 (148) (7,130) $ (282)
Ending balance, treasury (in shares) at Dec. 31, 2021           10,000,000
Consolidated Statements of Stockholders' Equity            
Net income 1,318     1,318    
Other comprehensive income (loss) 1,329       1,329  
Common stock issued for employee equity awards (shares) [1]   2,000,000       1,000,000
Common stock issued for employee equity awards [1] 48   79     $ (31)
Ending balance (in shares) at Dec. 31, 2022   652,000,000        
Ending balance at Dec. 31, 2022 $ 6,582 $ 0 11,526 1,170 (5,801) $ (313)
Ending balance, treasury (in shares) at Dec. 31, 2022 10,535,033         11,000,000
Consolidated Statements of Stockholders' Equity            
Net income $ 4,609     4,609    
Dividends declared ($0.20 per share) (129)     (129)    
Other comprehensive income (loss) (44)       (44)  
Common stock issued for employee equity awards (shares) [1]   3,000,000        
Common stock issued for employee equity awards [1] 87   115     $ (28)
Ending balance (in shares) at Dec. 31, 2023   655,000,000        
Ending balance at Dec. 31, 2023 $ 11,105 $ 0 $ 11,641 $ 5,650 $ (5,845) $ (341)
Ending balance, treasury (in shares) at Dec. 31, 2023 11,224,246         11,000,000
[1] Treasury shares were withheld for payment of taxes, at a weighted average price per share of $40.08, $40.52 and $38.87 in 2023, 2022 and 2021, respectively.
v3.24.0.1
Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Statement of Stockholders' Equity [Abstract]      
Cash dividends declared per share (USD per share) $ 0.20    
Treasury shares withheld for payment of taxes, weighted average price per share (USD per share) $ 40.08 $ 40.52 $ 38.87
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Basis of Presentation

Delta Air Lines, Inc., a Delaware corporation, provides scheduled air transportation for passengers and cargo throughout the United States ("U.S.") and around the world. Our Consolidated Financial Statements include the accounts of Delta Air Lines, Inc. and our consolidated subsidiaries and have been prepared in accordance with generally accepted accounting principles in the U.S. ("GAAP"). We are not the primary beneficiary of, nor do we have a controlling financial interest in, any variable interest entity. Accordingly, we have not consolidated any variable interest entity.

We have marketing alliances with other airlines to enhance our access to domestic and international markets. These arrangements may include codesharing, reciprocal loyalty program benefits, shared or reciprocal access to passenger lounges, joint promotions, common use of airport gates and ticket counters, office co-location and other marketing agreements. We have received antitrust immunity for certain marketing arrangements, which enables us to offer a more integrated route network and develop common sales, marketing and discount programs for customers. Some of our marketing arrangements provide for the sharing of revenues and expenses. Revenues and expenses associated with collaborative arrangements are presented on a gross basis in the applicable line items on our Consolidated Statements of Operations ("income statement").

We have reclassified certain prior period amounts to conform to the current period presentation. Unless otherwise noted, all amounts disclosed are stated before consideration of income taxes.

Use of Estimates

We are required to make estimates and assumptions when preparing our Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the amounts reported in our Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates.

Recent Accounting Standards

Standards Effective in Future Years

Fair Value of Equity Investments. In June 2022, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2022-03, "Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions." Under this standard, a contractual restriction on the sale of an equity security is not considered in measuring the security's fair value. The standard also requires certain disclosures for equity securities that are subject to contractual restrictions. The ASU becomes effective January 1, 2024, however we early adopted this standard as of December 31, 2023. The new standard does not impact the valuation of our equity investments, but we have included the newly required disclosures related to the contractual sale restrictions associated with our investment in Wheels Up Experience Inc. ("Wheels Up"). See Note 4, "Investments," for additional details.

Segment Reporting. In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. We are assessing the impact of this ASU and upon adoption expect that any impact would be limited to additional segment expense disclosures in the footnotes to our Consolidated Financial Statements.

Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. We are assessing the impact of this ASU and upon adoption may be required to include certain additional disclosures in the footnotes to our Consolidated Financial Statements.
Significant Accounting Policies

Our significant accounting policies are disclosed below or included within the topic-specific notes included herein.

Cash and Cash Equivalents and Short-Term Investments

Short-term, highly liquid investments with maturities of three months or less when purchased are classified as cash and cash equivalents. Investments with maturities of greater than three months, but not in excess of one year, when purchased are classified as short-term investments and are stated at fair value. Investments with maturities beyond one year when purchased may be classified as short-term investments if they are expected to be available to support our short-term liquidity needs. Our short-term investments in debt securities purchased prior to October 1, 2022 are classified as fair value investments under the fair value option and unrealized gains and losses are recorded in non-operating expense. Our short-term investments in debt securities purchased on or after October 1, 2022 are classified as available-for-sale investments and are stated at fair value with unrealized gains and losses recorded in accumulated other comprehensive income/(loss) ("AOCI"). Realized gains and losses on these investments are recorded in non-operating expense.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets ("balance sheets") that sum to the total of the same such amounts shown within the Consolidated Statements of Cash Flows ("cash flows statement").

Reconciliation of cash, cash equivalents and restricted cash
December 31,
(in millions)202320222021
Current assets:
Cash and cash equivalents$2,741 $3,266 $7,933 
Restricted cash included in prepaid expenses and other199 138 163 
Noncurrent assets:
Restricted cash included in other noncurrent assets455 69 473 
Total cash, cash equivalents and restricted cash$3,395 $3,473 $8,569 

Inventories

Fuel. As part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel, our wholly owned subsidiary, Monroe Energy, LLC ("Monroe"), operates the Trainer oil refinery. Refined products (finished goods) and feedstock and blendstock inventories (work-in-process) are both carried at the lower of cost and net realizable value. We use jet fuel in our airline operations that is produced by the refinery and procured through the exchanges with third parties of gasoline, diesel and other refined products ("non-jet fuel products") the refinery produces. Cost is determined using the first-in, first-out method. Costs include the raw material consumed plus direct manufacturing costs (such as labor, utilities and supplies) as incurred and an applicable portion of manufacturing overhead.

Expendables Parts and Supplies. Inventories of expendable parts related to flight equipment, which cannot be economically repaired, reconditioned or reused after removal from the aircraft, are carried at moving average cost and charged to aircraft maintenance materials and outside repairs as consumed. An allowance for obsolescence is provided over the remaining useful life of the related fleet. We also provide allowances for parts identified as excess or obsolete to reduce the carrying costs to the lower of cost or net realizable value. These parts are estimated to have residual value of 5% of the original cost.

Accounting for Refinery Related Buy/Sell Agreements

To the extent that we receive jet fuel for non-jet fuel products exchanged under buy/sell agreements, we account for these transactions as nonmonetary exchanges. We have recorded these nonmonetary exchanges at the carrying amount of the non-jet fuel products transferred within aircraft fuel and related taxes on the income statement.
Derivatives

Changes in fuel prices, interest rates and foreign currency exchange rates impact our results of operations. In an effort to manage our exposure to these risks, we may enter into derivative contracts and adjust our derivative portfolio as market conditions change. Our derivative contracts are recognized at fair value on our balance sheets and had net balances of $5 million and $47 million at December 31, 2023 and 2022, respectively. See Note 3, "Fair Value Measurements," for further information regarding our derivative contracts.

Long-Lived Assets

Our long-lived lived assets include property and equipment, net and operating lease right-of-use ("ROU") assets on our balance sheets. See Note 7, "Leases," for further information regarding our leases. The following table summarizes our property and equipment:

Property and equipment by classification
December 31,
(in millions, except for estimated useful life)Estimated Useful Life20232022
Flight equipment(1)
25-34 years
$40,976 $38,091 
Ground property and equipment
3-40 years
9,986 8,996 
Information technology-related assets
3-15 years
3,307 3,375 
Flight and ground equipment under finance leasesShorter of lease term or estimated useful life1,862 1,950 
Advance payments for equipment1,062 1,067 
Less: accumulated depreciation and amortization(2)
(21,707)(20,370)
Total property and equipment, net$35,486 $33,109 
(1)Includes aircraft and associated engines and parts.
(2)Includes accumulated amortization for flight and ground equipment under finance leases in the amount of $525 million and $463 million at December 31, 2023 and 2022, respectively.

We record property and equipment at cost and depreciate or amortize these assets on a straight-line basis to their estimated residual values over their estimated useful lives. The estimated useful life for leasehold improvements is the shorter of lease term or estimated useful life. Depreciation and amortization expense related to our property and equipment was $2.3 billion, $2.1 billion and $2.0 billion for the years ended December 31, 2023, 2022 and 2021, respectively. Residual values for owned aircraft, engines, spare parts and simulators are generally 5% to 10% of cost.

We capitalize certain internal and external costs incurred to develop and implement software and amortize those costs over an estimated useful life of three to fifteen years. Included in the depreciation and amortization expense discussed above, we recorded $340 million, $307 million and $301 million for amortization of capitalized software for the years ended December 31, 2023, 2022 and 2021, respectively. The net book value of these assets, which are included in information technology-related assets above, totaled $932 million and $891 million at December 31, 2023 and 2022, respectively.

Our tangible assets consist primarily of flight equipment, which is mobile across geographic markets. Accordingly, assets are not allocated to specific geographic regions.

We review flight equipment, ROU assets and other long-lived assets used in operations for impairment losses when events and circumstances indicate the assets may be impaired. Factors which could be indicators of impairment include, but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in fleet fair values and (5) changes to the regulatory environment. For long-lived assets held for sale, we discontinue depreciation and record impairment losses when the carrying amount of these assets is greater than the fair value less the cost to sell.

To determine whether impairments exist for aircraft used in operations, we group assets at the fleet type level or at the contract level for aircraft operated by third-party regional carriers (i.e., the lowest level for which there are identifiable cash flows) and then estimate future cash flows based on projections of capacity, passenger mile yield, fuel and labor costs and other relevant factors. If an asset group is impaired, the impairment loss recognized is the amount by which the asset group's carrying amount exceeds its estimated fair value. We estimate aircraft fair values using published sources, appraisals and bids received from third parties, as available.
Income Taxes

We account for deferred income taxes under the liability method. We recognize deferred tax assets and liabilities based on the tax effects of temporary differences between the financial statement and tax basis of assets and liabilities, as measured by current enacted tax rates. Deferred tax assets and liabilities are net by jurisdiction and are recorded as noncurrent on the balance sheets.

We have elected to recognize global intangible low tax income in the period it arises and do not recognize deferred taxes for basis differences that may reverse in future years.

A valuation allowance is recorded to reduce deferred tax assets when necessary. We periodically assess whether it is more likely than not that we will generate sufficient taxable income to realize our deferred income tax assets. We establish valuation allowances if it is more likely than not that we will be unable to realize our deferred income tax assets. In making this determination, we consider available positive and negative evidence and make certain assumptions. We consider, among other things, projected future taxable income, scheduled reversals of deferred tax liabilities, the overall business environment, our historical financial results and tax planning strategies. See Note 11, "Income Taxes," for further information on our deferred income taxes.

Fuel Card Obligation

We have a purchasing card with American Express for the purpose of buying jet fuel and crude oil. The card carried a maximum credit limit of $1.1 billion as of December 31, 2023 and must be paid monthly. At both December 31, 2023 and 2022, we had $1.1 billion outstanding on this purchasing card and the activity was classified as a financing activity in our cash flows statement.

Manufacturers' Credits

We periodically receive credits in connection with the acquisition of aircraft and engines. These credits are deferred until the aircraft and engines are delivered, and then applied as a reduction to the cost of the related equipment.

Maintenance Costs

We record maintenance costs related to our mainline and regional fleets in aircraft maintenance materials and outside repairs and regional carrier expense, respectively. Maintenance costs are expensed as incurred, except for costs incurred under power-by-the-hour contracts, which are expensed based on actual hours flown. Power-by-the-hour contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per flight cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized and amortized over the remaining estimated useful life of the asset or the remaining lease term, whichever is shorter.

Advertising Costs

We expense advertising costs in passenger commissions and other selling expenses in the year the advertising first takes place. Advertising expense was $347 million, $302 million and $198 million for the years ended December 31, 2023, 2022 and 2021, respectively.

Commissions and Merchant Fees

Passenger sales commissions and merchant fees are recognized in passenger commissions and other selling expenses when the related revenue is recognized.
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REVENUE RECOGNITION
 12 Months Ended
Dec. 31, 2023
Revenue from Contract with Customer [Abstract]  
REVENUE RECOGNITION REVENUE RECOGNITION
Passenger Revenue

Passenger revenue is composed of passenger ticket sales, loyalty travel awards and travel-related services performed in conjunction with a passenger’s flight.

Passenger revenue by category
Year Ended December 31,
(in millions)202320222021
Ticket$43,596 $35,626 $19,339 
Loyalty travel awards3,462 2,898 1,786 
Travel-related services1,851 1,694 1,394 
Total passenger revenue$48,909 $40,218 $22,519 

Ticket

Passenger Tickets. We defer sales of passenger tickets to be flown by us or that we sell on behalf of other airlines in our air traffic liability. Passenger revenue is recognized when we provide transportation. For tickets that we sell on behalf of other airlines, we reduce the air traffic liability when consideration is remitted to those airlines. The air traffic liability primarily includes sales of passenger tickets with scheduled departure dates in the future and travel credits, which can be applied as payment toward the cost of a ticket. We periodically evaluate the estimated air traffic liability and may record adjustments in our income statement. These adjustments relate primarily to tickets that expire unused ("ticket breakage"), refunds, exchanges, transactions with other airlines and other items for which final settlement occurs in periods subsequent to the sale of the related tickets at amounts other than the original sales price.

We recognized approximately $7.4 billion, $4.2 billion and $2.2 billion in passenger revenue during the years ended December 31, 2023, 2022 and 2021, respectively, that had been recorded in our air traffic liability balance at the beginning of those periods.

As of December 31, 2023, all of our air traffic liability was recorded as a current liability. As of December 31, 2022, our air traffic liability was $8.3 billion, of which $100 million was included in other noncurrent liabilities on our balance sheet due to ticket validity extensions related to certain tickets and travel credits as of the end of 2022.

Ticket Breakage. We estimate the value of ticket breakage and recognize revenue at the scheduled flight date. Our ticket breakage estimates are primarily based on historical experience, ticket contract terms and customers’ travel behavior.

Regional Carriers. Our regional carriers include both third-party regional carriers with which we have contract carrier agreements ("contract carriers") and Endeavor Air, Inc., our wholly owned subsidiary. Our contract carrier agreements are primarily structured as capacity purchase agreements where we purchase all or a portion of the contract carrier's capacity and are responsible for selling the seat inventory we purchase. We record revenue related to our capacity purchase agreements in passenger revenue and the related expenses in regional carrier expense. See Note 10, "Commitments and Contingencies," for additional information regarding contract carrier agreements.

Loyalty Travel Awards

Loyalty travel awards revenue is related to the redemption of mileage credits ("miles") for travel. We recognize loyalty travel awards revenue in passenger revenue as miles are redeemed and transportation is provided. See below for discussion of our loyalty program accounting policies.

Travel-Related Services

Travel-related services are primarily composed of services performed in conjunction with a passenger’s flight, including baggage fees, administrative fees, and on-board sales. We recognize revenue for these services when the related transportation service is provided.
Loyalty Program

Our SkyMiles loyalty program generates customer loyalty by rewarding customers with incentives to travel on Delta. This program allows customers to earn miles by flying on Delta, Delta Connection carriers and other airlines that participate in the loyalty program. When traveling, customers earn miles primarily based on the passenger's loyalty program status, fare class and ticket price. Customers can also earn miles through participating companies. Miles are redeemable by customers in future periods for air travel on Delta and other participating airlines, access to Delta Sky Club and other program awards. To facilitate transactions with participating companies, we sell miles to non-airline businesses and other airlines.

The loyalty program includes two types of transactions that are considered revenue arrangements with multiple performance obligations (1) passenger ticket sales earning miles and (2) sale of miles to participating companies.

Passenger Ticket Sales Earning Miles. Passenger ticket sales earning miles provide customers with (1) miles earned and (2) air transportation, which are each considered performance obligations. We value each performance obligation on a standalone basis. To value the miles earned, we consider the quantitative value a passenger receives by redeeming miles for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV"). Our estimate of ETV is adjusted for miles that are not likely to be redeemed ("mileage breakage"). We use statistical models to estimate mileage breakage based on historical redemption patterns. A change in assumptions regarding the redemption activity for miles or the estimated fair value of miles expected to be redeemed could have a material impact on our revenue in the year in which the change occurs and in future years. We recognize mileage breakage proportionally during the period in which the remaining miles are actually redeemed.

We defer revenue for the miles when earned and recognize loyalty travel awards in passenger revenue as the miles are redeemed and transportation is provided. We record the air transportation portion of the passenger ticket sales in air traffic liability and recognize passenger revenue when we provide transportation or if the ticket goes unused.

Sale of Miles to Participating Companies. Customers earn miles based on their spending with participating companies, such as credit card, retail, ridesharing, car rental and hotel companies, with which we have marketing agreements to sell miles. Our contracts to sell miles under these marketing agreements have multiple performance obligations. Payments are typically due to us monthly based on the volume of miles sold during the period, and the initial terms of our marketing contracts are from one to thirteen years. During the years ended December 31, 2023, 2022 and 2021, total cash sales from marketing agreements related to our loyalty program were $6.9 billion, $5.7 billion and $4.1 billion, respectively, which are allocated to travel and other performance obligations, as discussed below.

Our most significant contract to sell miles relates to our co-brand credit card relationship with American Express. Our agreements with American Express provide for joint marketing, grant certain benefits to Delta-American Express co-branded credit card holders ("cardholders") and American Express Membership Rewards program participants, and allow American Express to market its services or products using our customer database. Cardholders earn miles for making purchases using co-branded cards, and certain cardholders may also check their first bag for free, are granted discounted access to Delta Sky Club lounges and receive priority boarding and other benefits while traveling on Delta. Additionally, participants in the American Express Membership Rewards program may exchange their points for miles under the loyalty program. We sell miles at agreed-upon rates to American Express which are then provided to their customers under the co-brand credit card program and the Membership Rewards program.

We account for marketing agreements, including those with American Express, by allocating the consideration to the individual products and services delivered. We allocate the value based on the relative selling prices of those products and services, which generally consist of award travel, priority boarding, baggage fee waivers, lounge access and the use of our brand. We determine our best estimate of the selling prices by using a discounted cash flow analysis using multiple inputs and assumptions, including (1) the expected number of miles awarded and number of miles redeemed, (2) ETV for the award travel obligation adjusted for mileage breakage, (3) published rates on our website for baggage fees, discounted access to Delta Sky Club lounges and other benefits while traveling on Delta, (4) brand value (using estimated royalties generated from the use of our brand) and (5) volume discounts provided to certain partners.

We defer the amount allocated to award travel as part of loyalty program deferred revenue and recognize loyalty travel awards in passenger revenue as the miles are redeemed and transportation is provided. Revenue allocated to services performed in conjunction with a passenger’s flight, such as baggage fee waivers, is recognized as travel-related services in passenger revenue when the related service is performed. Revenue allocated to Delta Sky Club lounge access is recognized as miscellaneous in other revenue as access is provided. Revenue allocated to the remaining performance obligations, primarily brand value, is recorded as loyalty program in other revenue as miles are delivered.
Current Activity of the Loyalty Program. Miles are combined in one homogeneous pool and are not separately identifiable. Therefore, the revenue is comprised of miles that were part of the loyalty program deferred revenue balance at the beginning of the period as well as miles that were issued during the period.

The table below presents the activity of the current and noncurrent loyalty program deferred revenue, and includes miles earned through travel and miles sold to participating companies, which are primarily through marketing agreements.

Loyalty program activity
(in millions)202320222021
Balance at January 1$7,882 $7,559 $7,182 
Miles earned4,173 3,419 2,238 
Travel miles redeemed(3,462)(2,898)(1,786)
Non-travel miles redeemed(173)(198)(75)
Balance at December 31$8,420 $7,882 $7,559 

The timing of mile redemptions can vary widely; however, the majority of new miles have historically been redeemed within two years of being earned. The loyalty program deferred revenue classified as a current liability represents our estimate of revenue expected to be recognized in the next twelve months based on projected redemptions, while the balance classified as a noncurrent liability represents our estimate of revenue expected to be recognized beyond twelve months.

Cargo Revenue

Cargo revenue is recognized when we provide the transportation.

Other Revenue
Year Ended December 31,
(in millions)202320222021
Refinery$3,379 $4,977 $3,229 
Loyalty program3,093 2,597 1,770 
Ancillary businesses840 846 793 
Miscellaneous1,104 894 556 
Total other revenue$8,416 $9,314 $6,348 

Refinery. This represents refinery sales to third parties. See Note 14, "Segments," for more information on revenue recognition within our refinery segment.

Loyalty Program. This relates to revenues from brand usage by third parties and other performance obligations embedded in miles sold, which are included within the total cash sales from marketing agreements, discussed above. This also includes the redemption of miles for non-travel awards.

Ancillary Businesses. This includes aircraft maintenance services we provide to third parties and our vacation wholesale operations.

Miscellaneous. This is primarily composed of lounge access, including access provided to certain American Express cardholders, and codeshare revenues.
Revenue by Geographic Region

Operating revenue for the airline segment is recognized in a specific geographic region based on the origin, flight path and destination of each flight segment. A significant portion of the refinery segment's revenues typically consists of fuel sales to support the airline, which is eliminated in the Consolidated Financial Statements. The remaining operating revenue for the refinery segment is included in the domestic region. Our passenger and operating revenue by geographic region are summarized in the following table:

Revenue by geographic region
Passenger RevenueOperating Revenue
Year Ended December 31,Year Ended December 31,
(in millions)202320222021202320222021
Domestic$33,968 $30,197 $18,468 $40,845 $38,478 $24,320 
Atlantic9,057 6,093 1,777 10,458 7,429 2,537 
Latin America3,798 2,889 1,873 4,292 3,334 2,284 
Pacific2,086 1,039 401 2,453 1,341 758 
Total$48,909 $40,218 $22,519 $58,048 $50,582 $29,899 

Accounts Receivable

Accounts receivable primarily consist of amounts due from credit card companies from the sale of passenger tickets, ancillary businesses, refinery sales and other companies for the purchase of miles under the loyalty program. We provide an allowance for uncollectible accounts using an expected credit loss model which represents our estimate of expected credit losses over the lifetime of the asset.

Passenger Taxes and Fees

We are required to charge certain taxes and fees on our passenger tickets, including U.S. federal transportation taxes, federal security charges, airport passenger facility charges and foreign arrival and departure taxes. These taxes and fees are assessments on the customer for which we act as a collection agent and these amounts are not included in passenger revenue. We record a liability when the amounts are collected and reduce the liability when payments are made to the applicable government agency or operating carrier (i.e., for codeshare-related fees).
v3.24.0.1
FAIR VALUE MEASUREMENTS
 12 Months Ended
Dec. 31, 2023
Fair Value Disclosures [Abstract]  
FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS
Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. Fair value is a market-based measurement that is determined based on assumptions that market participants would use in pricing an asset or liability. Each fair value measurement is classified into one of the following levels based on the information used in the valuation:

•Level 1. Observable inputs such as quoted prices in active markets.

•Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly.

•Level 3. Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

Assets and liabilities measured at fair value are based on the valuation techniques identified in the tables below. The valuation techniques are as follows:

(a)Market Approach. Prices and other relevant information generated by observable transactions involving identical or comparable assets or liabilities.

(b)Income Approach. Techniques to convert future amounts to a single present value amount based on market expectations (including present value techniques and option-pricing models).
Assets (Liabilities) Measured at Fair Value on a Recurring Basis(1)
December 31, 2023Valuation Technique
(in millions)TotalLevel 1Level 2Level 3
Cash equivalents$1,545 $1,545 $— $— (a)
Restricted cash equivalents653 653 — — (a)
Short-term investments
U.S. Government securities859 204 655 — (a)
Corporate obligations218 — 218 — (a)
Other fixed income securities50 — 50 — (a)
Long-term investments and related2,867 2,614 134 119 (a)(b)
Hedge derivatives, net
Fuel hedge contracts5 — 5 — (a)(b)

December 31, 2022Valuation Technique
(in millions)TotalLevel 1Level 2Level 3
Cash equivalents$2,021 $2,021 $— $— (a)
Restricted cash equivalents206 206 — — (a)
Short-term investments
U.S. Government securities1,587 122 1,465 — (a)
Corporate obligations1,614 — 1,614 — (a)
Other fixed income securities67 — 67 — (a)
Long-term investments1,450 1,305 38 107 (a)(b)
Hedge derivatives, net
Fuel hedge contracts(47)— (47)— (a)(b)
(1)See Note 9, "Employee Benefit Plans," for fair value of benefit plan assets.

Cash Equivalents and Restricted Cash Equivalents. Cash equivalents generally consist of money market funds. Restricted cash equivalents are recorded in prepaid expenses and other and other noncurrent assets on our balance sheets and generally consist of money market funds, time deposits, commercial paper and negotiable certificates of deposit, which primarily relate to proceeds from debt issued to finance, among other things, a portion of the construction costs for our new terminal facilities at New York's LaGuardia Airport as well as certain self-insurance obligations and airport commitments. The fair value of these cash equivalents is based on a market approach using prices generated by market transactions involving identical or comparable assets.

Short-Term Investments. The fair values of our short-term investments are based on a market approach using industry standard valuation techniques that incorporate observable inputs such as quoted market prices, interest rates, benchmark curves, credit ratings of the security and other observable information.

As of December 31, 2023, the estimated fair value of our short-term investments was $1.1 billion. These investments are expected to mature in one year or less.

Long-Term Investments and Related. Our long-term investments measured at fair value primarily consist of equity investments, which are valued based on market prices or other observable transactions and inputs, and are recorded in equity investments on our balance sheets. Our equity investments in private companies are classified as Level 3 in the fair value hierarchy as their equity is not traded on a public exchange and our valuations incorporate certain unobservable inputs, including non-public equity issuances. As of December 31, 2023 and December 31, 2022, our equity investment in Wheels Up was classified as Level 1 in the fair value hierarchy. In the September 2023 quarter, our Wheels Up investment was classified as Level 3 after we determined the quoted price of its publicly-traded shares did not represent fair value due to the short time between closing of Wheels Up's credit facility and our quarterly reporting date. Given the amount of time that elapsed by December 31, 2023, we returned to valuing our equity investment in Wheels Up using the closing price of its shares at year end as traded on the New York Stock Exchange. Fair value measurement using unobservable inputs is inherently uncertain, and a change in significant inputs could result in different fair values. During the year ended December 31, 2023 there were no material gains or losses related to investments classified as Level 3 as a result of fair value adjustments. See Note 4, "Investments," for further information on our long-term investments.
Hedge Derivatives. A portion of our derivative contracts may be negotiated over-the-counter with counterparties without going through a public exchange. Accordingly, our fair value assessments give consideration to the risk of counterparty default (as well as our own credit risk). Such contracts would be classified as Level 2 within the fair value hierarchy. The remainder of our hedge contracts may be comprised of futures contracts, which are traded on a public exchange. These contracts would be classified within Level 1 of the fair value hierarchy.

•Fuel Hedge Contracts. Our derivative contracts to hedge the financial risk from changing fuel prices are related to Monroe’s inventory. Our fuel hedge portfolio may consist of a combination of options, swaps or futures. Option and swap contracts are valued under income approaches using option pricing models and discounted cash flow models, respectively, based on data either readily observable in public markets, derived from public markets or provided by counterparties who regularly trade in public markets. Futures contracts and options on futures contracts are traded on a public exchange and valued based on quoted market prices. We recognized losses of $6 million, $394 million and $146 million on our fuel hedge contracts in aircraft fuel and related taxes on our income statement for the years ended December 31, 2023, 2022 and 2021, respectively. The losses recognized during 2023 were composed of $58 million of settlements on contracts and $52 million of mark-to-market adjustments. Expense from the settlement of closed contracts is offset by higher operating profits at Monroe from higher pricing. See Note 14, "Segments," for further information on our Monroe refinery segment.
v3.24.0.1
INVESTMENTS
 12 Months Ended
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]  
INVESTMENTS INVESTMENTS
We have developed strategic relationships with a number of airlines and airline services companies through joint ventures and other forms of cooperation and support, including equity investments. Our equity investments reinforce our commitment to these relationships and generally enhance our ability to offer input to the investee on strategic issues and direction, in some cases through representation on the board of directors of the investee.

Fair Value Investments. Changes in the valuation of investments accounted for at fair value are recorded in gain/(loss) on investments, net in our income statement within non-operating expense and are driven by changes in stock prices, foreign currency fluctuations and other valuation techniques for investments in companies without publicly-traded shares.

Equity Method Investments. We record our share of our equity method investees' financial results in our income statement as described in the table below.

Equity investments ownership interest and carrying value
Accounting TreatmentOwnership InterestCarrying Value
(in millions)December 31, 2023December 31, 2022December 31, 2023December 31, 2022
Air France-KLMFair Value3 %3 %$110 $97 
China EasternFair Value2 %2 %134 189 
CLEARFair Value6 %5 %171 227 
Grupo Aeroméxico
Equity Method(1)
20 %20 %421 412 
Hanjin-KAL
Fair Value(2)
15 %15 %561 296 
LATAMFair Value10 %10 %658 403 
Unifi Aviation
Equity Method(3)
49 %49 %162 165 
Wheels Up
Fair Value(4)
38 %21 %903 54 
Other investmentsVarious337 285 
Equity investments$3,457 $2,128 
(1)Results are included in miscellaneous, net in our income statement under non-operating expense.
(2)At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL.
(3)Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations.
(4)See below for additional information about our ownership interest and voting rights.
Wheels Up. During 2023, we announced an expanded strategic partnership with Wheels Up, which included an agreement for a new credit facility to Wheels Up. This new credit facility is comprised of a $390 million term loan, of which we contributed $150 million and several other lenders contributed the remaining $240 million, and a $100 million liquidity facility that we made available to Wheels Up in the event the company's liquidity falls below $100 million. In connection with the credit facility, the term loan investors received newly issued shares of Wheels Up's common stock representing 95% of Wheels Up's outstanding equity on a fully diluted basis as of the closing of the initial extension of credit.

Our $150 million cash contribution was reflected as an investing outflow in our cash flows statement and allocated on a relative fair value basis to a loan receivable within other noncurrent assets and an equity investment on our balance sheet. Combined with our previous ownership stake, this new investment provides us with a 38% equity interest in Wheels Up. Delta's voting rights with respect to its Wheels Up equity interest are capped at 29.9%.

As a result of the transaction, we concluded that Wheels Up is a variable interest entity ("VIE"). A VIE requires consolidation by the entity’s primary beneficiary. We determined that we are not the primary beneficiary after assessing the decision-making process for the significant activities of Wheels Up, concluding that Wheels Up's Board of Directors continues to possess the decision-making authority over the significant activities, and we do not control Wheels Up's Board. Based on this assessment, Wheels Up is not consolidated in our financial statements.

We continue to account for our Wheels Up equity interest under the fair value option, as originally elected as part of our initial acquisition of Wheels Up shares in 2020. During 2023, we recorded a $786 million mark-to-market gain on our investment in Wheels Up based on the closing price of its shares as traded on the New York Stock Exchange. As of December 31, 2023, Wheels Up's public float was under 5% of the total outstanding shares which contributed to significant volatility in the value of our Wheels Up equity investment since the announcement of Wheels Up's credit facility in September 2023. The Wheels Up shares issued to Delta and the other term loan lenders were unregistered as of December 31, 2023 and are subject to a contractual transfer restriction until the first anniversary of the credit facility (September 2024). Following the expiration of this restriction, our equity investment in Wheels Up will be subject to certain, more limited transfer restrictions. We also account for our loan receivable at fair value, as the fair value option is applied to all of an investor's financial interests in the same entity. None of the $100 million liquidity facility has been drawn as of December 31, 2023.

Other Investments

This category includes various investments that are accounted for at fair value or under the equity method, depending on our ownership interest and the level of influence conveyed by our investment. Among others, this category includes our equity method investments in Virgin Atlantic and JFK IAT Member LLC.

Virgin Atlantic. The carrying value of our investment in Virgin Atlantic remains zero as of December 31, 2023. We maintain our 49% equity interest and continue to track our share of Virgin Atlantic's losses under the equity method of accounting. These previously unrecognized losses are only recorded to the extent we make additional investments in Virgin Atlantic (i.e., additional shareholder support). As of December 31, 2023, we have approximately $400 million of unrecognized equity method losses related to our 49% interest in Virgin Atlantic.

JFK IAT Member LLC is discussed further in Note 8, "Airport Redevelopment."
v3.24.0.1
GOODWILL AND INTANGIBLE ASSETS
 12 Months Ended
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]  
GOODWILL AND INTANGIBLE ASSETS GOODWILL AND INTANGIBLE ASSETS
Goodwill and Indefinite-Lived Intangible Assets

Our goodwill and identifiable intangible assets relate to the airline segment. We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. We assess the value of our goodwill and indefinite-lived assets under either a qualitative or quantitative approach. Under a qualitative approach, we consider various market factors, including certain of the key assumptions listed below. We analyze these factors to determine if events and circumstances have affected the fair value of goodwill and indefinite-lived intangible assets. If we determine that it is more likely than not that the asset may be impaired, we use the quantitative approach to assess the asset's fair value and the amount of the impairment. Under a quantitative approach, we calculate the fair value of the asset incorporating the key assumptions listed below into our calculation.
We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions (1) forecasted revenues, expenses and cash flows, (2) current discount rates, (3) observable market transactions and (4) anticipated changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals). These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. We recognize an impairment charge if the asset's carrying value exceeds its estimated fair value.

Changes in certain events and circumstances could result in impairment or a change from indefinite-lived to definite-lived. Factors which could cause impairment include, but are not limited to (1) negative trends in our market capitalization, (2) reduced profitability resulting from lower passenger mile yields or higher input costs (primarily related to fuel and employees), (3) lower passenger demand as a result of weakened U.S. and global economies or other factors, (4) interruption to our operations due to a prolonged employee strike, terrorist attack or other reasons, (5) changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals), (6) competitive changes by other airlines and (7) strategic changes to our operations leading to diminished utilization of the intangible assets.

Identifiable Intangible Assets. Indefinite-lived assets are not amortized and consist of routes, slots, the Delta tradename and assets related to alliances and collaborative arrangements. Definite-lived intangible assets consist primarily of marketing and maintenance service agreements and are amortized on a straight-line basis or under the undiscounted cash flows method over the estimated economic life of the respective agreements. Costs incurred to renew or extend the term of an intangible asset are expensed as incurred.

During the December 2023 quarter, we performed a quantitative valuation of our goodwill and indefinite-lived intangible assets as the most recent quantitative analysis was several years ago. These quantitative impairment tests of goodwill and intangibles concluded that there was no indication of impairment as the fair values exceeded our carrying values.

Goodwill and indefinite-lived intangible assets by category
Carrying Value atExcess Fair Value at 2023 Testing Date
(in millions)December 31, 2023December 31, 2022
Goodwill$9,753 $9,753 
>100%
International routes and slots2,583 2,583 
20% to >100%
Airline alliances1,863 1,863 
30% to >100%
Delta tradename850 850 
>100%
Domestic slots622 622 
60% to >100%
Total$15,671 $15,671 

International Routes and Slots. This primarily relates to Pacific route authorities and slots at capacity-constrained airports in Asia, and slots at London-Heathrow airport.

Airline Alliances. This primarily relates to our commercial agreements with LATAM and our SkyTeam partners.

Domestic Slots. This primarily relates to our slots at New York-LaGuardia and Washington-Reagan National airports.
Definite-Lived Intangible Assets

Definite-lived intangible assets by category
December 31, 2023December 31, 2022
(in millions)Gross Carrying Value 
Accumulated Amortization		Gross Carrying ValueAccumulated Amortization
Marketing agreements$730 $(708)$730 $(704)
Maintenance contracts192 (150)192 (145)
Other54 (53)54 (53)
Total$976 $(911)$976 $(902)

Amortization expense was $9 million, $9 million and $10 million for the years ended December 31, 2023, 2022 and 2021, respectively. Based on our definite-lived intangible assets at December 31, 2023, we estimate that we will incur approximately $8 million of amortization expense annually from 2024 through 2028.
v3.24.0.1
DEBT
 12 Months Ended
Dec. 31, 2023
Debt Disclosure [Abstract]  
DEBT DEBT
The following table summarizes our debt as of the dates indicated below:

Summary of outstanding debt by category
Maturity Dates
Interest Rate(s) Per Annum at December 31, 2023
December 31,
(in millions)20232022
Unsecured Payroll Support Program Loans2030to 20311.00%$3,496 $3,496 
Unsecured notes2024to20292.90%to7.38%2,590 2,997 
Financing arrangements secured by SkyMiles assets:
SkyMiles Notes(1)
2024to20284.50%and 4.75%4,518 5,144 
SkyMiles Term Loan(1)(2)
2024to20279.17%1,772 2,820 
NYTDC Special Facilities Revenue Bonds(1)
2024to20454.00%to6.00%3,656 2,838 
Financing arrangements secured by aircraft:
Certificates(1)
2024to20282.00%to8.00%1,591 1,802 
Notes(1)(2)
2024to20336.72%to7.65%165 813 
Financing arrangements secured by slots, gates and/or routes:
2020 Senior Secured Notes20257.00%838 1,542 
2018 Revolving Credit Facility(2)
2026to2028Undrawn— — 
Other financings(1)(2)
2024to20302.51%to5.00%67 67 
Other revolving credit facilities(2)
2024to2026Undrawn— — 
Total secured and unsecured debt18,693 21,519 
Unamortized (discount)/premium and debt issuance cost, net and other(83)(138)
Total debt18,610 21,381 
Less: current maturities(2,625)(2,055)
Total long-term debt$15,985 $19,326 
(1)Due in installments.
(2)Certain financings are comprised of variable rate debt. All variable rates are equal to SOFR (generally subject to a floor) or another index rate plus a specified margin.

Early Settlement of Outstanding Notes

During 2023, we repurchased a principal amount of $1.4 billion of various secured and unsecured notes and a portion of the SkyMiles Term Loan on the open market and made early principal repayments of $585 million on various notes secured by aircraft. Collectively, these payments resulted in a $63 million loss on extinguishment of debt, which is recorded in non-operating expense in our income statement.
Availability Under Revolving Facilities

As of December 31, 2023, we had approximately $2.9 billion undrawn and available under our revolving credit facilities. In addition, we had $450 million of outstanding letters of credit as of December 31, 2023 that did not affect the availability under our revolvers.

New York Transportation Development Corporation ("NYTDC") Special Facilities Revenue Bonds, Series 2023

In the December 2023 quarter, the NYTDC issued Special Facilities Revenue Bonds ("Series 2023 Bonds") in the aggregate principal amount of $878 million. We entered into loan agreements with the NYTDC to use the proceeds from the Series 2023 Bonds to finance a portion of the costs of the construction project that is currently in process at LaGuardia Airport. The proceeds from the Series 2023 Bonds are recorded in other noncurrent assets on our balance sheets. See Note 8, "Airport Redevelopment," for further information on our LaGuardia Airport project.

We are required to pay debt service on the Series 2023 Bonds through payments under loan agreements with NYTDC, and we have guaranteed the Series 2023 Bonds.

2018 Revolving Credit Facility

In the December 2023 quarter, we entered into an amended and restated credit agreement (the "A&R Credit Facility") which amends and restates the previous 2018 revolving credit facility. The A&R Credit Facility was undrawn at the time we entered into it and at December 31, 2023. The A&R Credit Facility contains a $1.325 billion three-year revolving facility, a $1.325 billion five-year revolving facility and a $360 million three-year standby letter of credit facility. Up to $250 million of each of the three-year and the five-year facilities can also be used for the issuance of letters of credit. The A&R Credit Facility contains an accordion feature under which the aggregate commitments can be increased up to $3.65 billion subject to certain conditions.

The A&R Credit Facility is secured by a first lien on collateral consistent with the existing credit agreement, which includes our Pacific route authorities and certain related assets. We also have the option of pledging additional collateral. The A&R Credit Facility provides for the release of the lien on the collateral if we receive and maintain an investment grade rating with stable outlook from at least two of the three rating agencies (such date on which the collateral release conditions are met, the "Collateral Release Date").

Fair Value of Debt

Market risk associated with our fixed- and variable-rate debt relates to the potential reduction in fair value and negative impact to future earnings, respectively, from an increase in interest rates. The fair value of debt, shown below, is principally based on reported market values, recently completed market transactions and estimates based on interest rates, maturities, credit risk and underlying collateral. Debt is primarily classified as Level 2 within the fair value hierarchy.

Fair value of outstanding debt
(in millions)December 31,
2023		December 31,
2022
Net carrying amount$18,610 $21,381 
Fair value$18,400 $20,700 
Covenants

Our debt agreements contain various affirmative, negative and financial covenants. For example, our credit facilities and our SkyMiles financing agreements, contain, among other things, a minimum liquidity covenant. The minimum liquidity covenant requires us to maintain at least $2.0 billion of liquidity (defined as cash, cash equivalents, short-term investments and aggregate principal amount committed and available to be drawn under our revolving credit facilities). Certain of our debt agreements also include collateral coverage ratios and limit our ability to (1) incur liens under certain circumstances, (2) dispose of collateral and (3) engage in mergers and consolidations or transfer all or substantially all of our assets. On or after the Collateral Release Date, collateral and liquidity covenants in the A&R Credit Facility will be replaced to include, among other things, (1) restrictions on our ability to place liens on, or to sell or otherwise dispose of, a designated pool of assets and (2) minimum fixed charge coverage ratio and minimum asset coverage ratio covenants. Our SkyMiles financing agreements include a debt service coverage ratio and also restrict our ability to, among other things, (1) modify the terms of the SkyMiles program, or otherwise change the policies and procedures of the SkyMiles program, in a manner that would reasonably be expected to materially impair repayment of the SkyMiles Debt, (2) sell pre-paid miles in excess of $550 million in the aggregate and (3) terminate or materially modify the intercompany arrangements governing the relationship between Delta and SkyMiles IP Ltd. with respect to the SkyMiles program.

Each of these restrictions, however, is subject to certain exceptions and qualifications that are set forth in these debt agreements. We were in compliance with the covenants in our debt agreements at December 31, 2023.

Future Maturities

The following table summarizes scheduled maturities of our debt for the years succeeding December 31, 2023:

Future debt maturities

(in millions)		Total DebtAmortization of
Debt (Discount)/Premium and Debt Issuance Cost, net and other
2024$2,633 $(49)
20252,006 (32)
20262,610 (6)
20272,315 — 
20281,884 — 
Thereafter7,245 4 
Total$18,693 $(83)$18,610 
v3.24.0.1
LEASES
 12 Months Ended
Dec. 31, 2023
Leases [Abstract]  
LEASES LEASES
We lease property and equipment under finance and operating leases. For leases with terms greater than 12 months, we record the related asset and obligation at the present value of the fixed minimum lease payments over the term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when appropriate. We do not separate lease and nonlease components of contracts, except for regional aircraft and information technology ("IT") assets as discussed below.

We use the rate implicit in the lease to discount lease payments to present value, when readily determinable. As the rate implicit in the lease is rarely readily determinable, we use our incremental borrowing rate, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date.

Some of our aircraft lease agreements include provisions for residual value guarantees. These guarantees represent an immaterial portion of our lease liability.
Aircraft

As of December 31, 2023, including aircraft operated by our regional carriers, we leased 225 aircraft, of which 111 were under finance leases and 114 were operating leases. Our aircraft leases had remaining lease terms of five months to 12 years.

In addition, we have regional aircraft leases that are embedded within our capacity purchase agreements and included in the ROU asset and lease liability. We allocated the consideration in each capacity purchase agreement to the lease and nonlease components based on their relative standalone fair values. Lease components of these agreements consist of 116 aircraft as of December 31, 2023 and nonlease components primarily consist of flight operations, in-flight and maintenance services. We determined our best estimate of the standalone fair value of the individual components by considering observable information including rates paid by our wholly owned subsidiary, Endeavor Air, Inc., and rates published by independent valuation firms. See Note 10, "Commitments and Contingencies," for additional information about our capacity purchase agreements.

Airport Facilities

Our facility leases are primarily for space at approximately 300 airports around the world that we serve. These leases reflect our use of airport terminals, office space, cargo warehouses and maintenance facilities. We generally lease space from government agencies that control the use of the airport, and as a result, these leases are classified as operating leases. The remaining lease terms vary from one month to 29 years. At the majority of the U.S. airports, the lease rates depend on airport operating costs or use of the facilities and are reset at least annually. Because of the variable nature of the rates, these leases are not recorded on our balance sheets as a ROU asset and lease liability.

Some airport facilities have fixed payment schedules, the most significant of which are New York-LaGuardia and New York-JFK. For those airport leases, we have recorded a ROU asset and lease liability representing the fixed component of the lease payments. See Note 8, "Airport Redevelopment," for more information on our significant airport redevelopment projects.

Other Ground Property and Equipment

We lease certain IT assets (including servers, mainframes, etc.), ground support equipment (including tugs, tractors, fuel trucks and de-icers), and various other equipment. The remaining lease terms range from one month to six years. Certain leased assets are embedded within various ground and IT service agreements. For ground service contracts, we have elected to include both the lease and nonlease components in the lease asset and lease liability balances on our balance sheets. For IT service contracts, we have elected to separate the lease and nonlease components and only the lease components are included in the lease asset and lease liability balances on our balance sheets. The amounts of these lease and nonlease components are not significant.
Lease Position

The table below presents the lease-related assets and liabilities recorded on the balance sheets.

Lease asset and liability balance sheet position by category
December 31,
(in millions)Classification on the Balance Sheet20232022
Assets
Operating lease assetsOperating lease right-of-use assets$7,004 $7,036 
Finance lease assetsProperty and equipment, net1,338 1,487 
Total lease assets$8,342 $8,523 
Liabilities
Current
OperatingCurrent maturities of operating leases$759 $714 
FinanceCurrent maturities of debt and finance leases358 304 
Noncurrent
OperatingNoncurrent operating leases6,468 6,866 
FinanceDebt and finance leases1,086 1,345 
Total lease liabilities$8,671 $9,229 
Weighted-average remaining lease term
Operating leases13 years13 years
Finance leases4 years5 years
Weighted-average discount rate
Operating leases
3.73 %4.30 %
Finance leases3.12 %3.05 %

Lease Costs

The table below presents certain information related to the lease costs for finance and operating leases.

Lease cost by category
Year Ended December 31,
(in millions)202320222021
Finance lease cost
Amortization of leased assets$109 $120 $131 
Interest of lease liabilities42 45 55 
Operating lease cost(1)
981 949 863 
Short-term lease cost(1)
258 281 245 
Variable lease cost(1)
2,230 1,859 1,599 
Total lease cost$3,620 $3,254 $2,893 
(1)Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense on our income statement.
Other Information

The table below presents supplemental cash flow information related to leases.

Supplemental lease-related cash flow information
Year Ended December 31,
(in millions)202320222021
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows for operating leases$1,230 $809 $999 
Operating cash flows for finance leases71 49 46 
Financing cash flows for finance leases264 363 336 

Undiscounted Cash Flows

The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets.

Future lease cash flows and reconciliation to the balance sheet
(in millions)Operating LeasesFinance Leases
2024$1,021 $395 
2025990 257 
2026899 192 
2027860 391 
2028772 164 
Thereafter4,705 157 
Total minimum lease payments9,247 1,556 
Less: amount of lease payments representing interest(2,020)(112)
Present value of future minimum lease payments7,227 1,444 
Less: current obligations under leases(759)(358)
Long-term lease obligations$6,468 $1,086 

As of December 31, 2023, we had additional leases that had not yet commenced of $151 million. These leases will commence in 2024 with lease terms of 4 to 19 years.
LEASES LEASES
We lease property and equipment under finance and operating leases. For leases with terms greater than 12 months, we record the related asset and obligation at the present value of the fixed minimum lease payments over the term. Many of our leases include rental escalation clauses, renewal options and/or termination options that are factored into our determination of lease payments when appropriate. We do not separate lease and nonlease components of contracts, except for regional aircraft and information technology ("IT") assets as discussed below.

We use the rate implicit in the lease to discount lease payments to present value, when readily determinable. As the rate implicit in the lease is rarely readily determinable, we use our incremental borrowing rate, which is based on the estimated interest rate for collateralized borrowing over a similar term of the lease at commencement date.

Some of our aircraft lease agreements include provisions for residual value guarantees. These guarantees represent an immaterial portion of our lease liability.
Aircraft

As of December 31, 2023, including aircraft operated by our regional carriers, we leased 225 aircraft, of which 111 were under finance leases and 114 were operating leases. Our aircraft leases had remaining lease terms of five months to 12 years.

In addition, we have regional aircraft leases that are embedded within our capacity purchase agreements and included in the ROU asset and lease liability. We allocated the consideration in each capacity purchase agreement to the lease and nonlease components based on their relative standalone fair values. Lease components of these agreements consist of 116 aircraft as of December 31, 2023 and nonlease components primarily consist of flight operations, in-flight and maintenance services. We determined our best estimate of the standalone fair value of the individual components by considering observable information including rates paid by our wholly owned subsidiary, Endeavor Air, Inc., and rates published by independent valuation firms. See Note 10, "Commitments and Contingencies," for additional information about our capacity purchase agreements.

Airport Facilities

Our facility leases are primarily for space at approximately 300 airports around the world that we serve. These leases reflect our use of airport terminals, office space, cargo warehouses and maintenance facilities. We generally lease space from government agencies that control the use of the airport, and as a result, these leases are classified as operating leases. The remaining lease terms vary from one month to 29 years. At the majority of the U.S. airports, the lease rates depend on airport operating costs or use of the facilities and are reset at least annually. Because of the variable nature of the rates, these leases are not recorded on our balance sheets as a ROU asset and lease liability.

Some airport facilities have fixed payment schedules, the most significant of which are New York-LaGuardia and New York-JFK. For those airport leases, we have recorded a ROU asset and lease liability representing the fixed component of the lease payments. See Note 8, "Airport Redevelopment," for more information on our significant airport redevelopment projects.

Other Ground Property and Equipment

We lease certain IT assets (including servers, mainframes, etc.), ground support equipment (including tugs, tractors, fuel trucks and de-icers), and various other equipment. The remaining lease terms range from one month to six years. Certain leased assets are embedded within various ground and IT service agreements. For ground service contracts, we have elected to include both the lease and nonlease components in the lease asset and lease liability balances on our balance sheets. For IT service contracts, we have elected to separate the lease and nonlease components and only the lease components are included in the lease asset and lease liability balances on our balance sheets. The amounts of these lease and nonlease components are not significant.
Lease Position

The table below presents the lease-related assets and liabilities recorded on the balance sheets.

Lease asset and liability balance sheet position by category
December 31,
(in millions)Classification on the Balance Sheet20232022
Assets
Operating lease assetsOperating lease right-of-use assets$7,004 $7,036 
Finance lease assetsProperty and equipment, net1,338 1,487 
Total lease assets$8,342 $8,523 
Liabilities
Current
OperatingCurrent maturities of operating leases$759 $714 
FinanceCurrent maturities of debt and finance leases358 304 
Noncurrent
OperatingNoncurrent operating leases6,468 6,866 
FinanceDebt and finance leases1,086 1,345 
Total lease liabilities$8,671 $9,229 
Weighted-average remaining lease term
Operating leases13 years13 years
Finance leases4 years5 years
Weighted-average discount rate
Operating leases
3.73 %4.30 %
Finance leases3.12 %3.05 %

Lease Costs

The table below presents certain information related to the lease costs for finance and operating leases.

Lease cost by category
Year Ended December 31,
(in millions)202320222021
Finance lease cost
Amortization of leased assets$109 $120 $131 
Interest of lease liabilities42 45 55 
Operating lease cost(1)
981 949 863 
Short-term lease cost(1)
258 281 245 
Variable lease cost(1)
2,230 1,859 1,599 
Total lease cost$3,620 $3,254 $2,893 
(1)Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense on our income statement.
Other Information

The table below presents supplemental cash flow information related to leases.

Supplemental lease-related cash flow information
Year Ended December 31,
(in millions)202320222021
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows for operating leases$1,230 $809 $999 
Operating cash flows for finance leases71 49 46 
Financing cash flows for finance leases264 363 336 

Undiscounted Cash Flows

The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets.

Future lease cash flows and reconciliation to the balance sheet
(in millions)Operating LeasesFinance Leases
2024$1,021 $395 
2025990 257 
2026899 192 
2027860 391 
2028772 164 
Thereafter4,705 157 
Total minimum lease payments9,247 1,556 
Less: amount of lease payments representing interest(2,020)(112)
Present value of future minimum lease payments7,227 1,444 
Less: current obligations under leases(759)(358)
Long-term lease obligations$6,468 $1,086 

As of December 31, 2023, we had additional leases that had not yet commenced of $151 million. These leases will commence in 2024 with lease terms of 4 to 19 years.
v3.24.0.1
AIRPORT REDEVELOPMENT
 12 Months Ended
Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]  
AIRPORT REDEVELOPMENT AIRPORT REDEVELOPMENT
New York-JFK Airport

We are enhancing and expanding our facilities at Terminal 4 of JFK to strengthen our competitive position and offer a premium travel experience for customers in New York City. Terminal 4 is operated by JFK International Air Terminal LLC ("IAT"), a private party, under its lease with the Port Authority of New York and New Jersey ("Port Authority"). We have a long-term agreement with IAT to sublease space in Terminal 4 through 2043 ("Sublease").

In 2021, the Port Authority approved plans to renovate and expand Terminal 4 in order to facilitate Delta's relocation from Terminal 2 and consolidation of its operations into Terminal 4. The project is adding 10 new gates and other complementary facilities, including an additional Delta Sky Club and a new Delta premium lounge. The project is estimated to cost approximately $1.6 billion and will be funded primarily with bonds issued in 2022 by the NYTDC for which our landlord, IAT, is the obligor. The majority of project costs are being used to expand or modify Delta's leased premises. Construction started in late 2021 and in 2023 we substantially completed a majority of Delta's portion of the project and consolidated all operations to Terminal 4. Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed, and therefore, we do not have the project asset or related obligation recorded on our balance sheets.
Equity Investment. We have an equity method investment in JFK IAT Member LLC, which owns IAT. The Sublease requires us to pay certain fixed management fees. We determined the investment is a variable interest entity and assessed whether we have a controlling financial interest in IAT. Our rights under the Sublease, with respect to management of Terminal 4, are consistent with rights granted to an anchor tenant under a standard airport lease. Accordingly, we do not consolidate this entity in our Consolidated Financial Statements. See Note 4, "Investments" for additional information on our equity investments.

Los Angeles International Airport ("LAX")

As part of the terminal redevelopment project at LAX, we are modernizing, upgrading, and providing post-security connection to Terminals 2 and 3. We announced this project and executed a modified lease agreement during 2016 with the City of Los Angeles (the "City"), which owns and operates LAX. This project includes a new centralized ticketing and arrival hall, a new security checkpoint, core infrastructure to support the City's planned airport people mover, ramp improvements and a post-security connector to the north side of the Tom Bradley International Terminal.

The project is expected to cost approximately $2.4 billion. A substantial majority of the project costs are being funded through the Regional Airports Improvement Corporation ("RAIC"), a California public benefit corporation, using a revolving credit facility provided by a group of lenders. The credit facility was executed in 2017 and we have guaranteed the obligations of the RAIC under the credit facility. During 2023, the revolving credit facility agreement was amended and the revolver capacity was reduced to $626 million. Loans made under the credit facility are being repaid with the proceeds from the City’s purchase of completed project assets. Under the lease agreement and subsequent project component approvals by the City's Board of Airport Commissioners, the City has appropriated to date approximately $1.8 billion to purchase completed project assets, representing the maximum allowable reimbursement by the City. Costs incurred in excess of the $1.8 billion maximum will not be reimbursed by the City. We currently expect our net project costs to be approximately $600 million, of which approximately $350 million has been reflected as investing activities and approximately $200 million as operating activities in our cash flows statement since the project started in 2017.

In 2020, we enhanced the project’s scope to include a more customer-friendly design of Terminal 3, an expanded Delta Sky Club and baggage system upgrades designed to increase the terminals’ operational efficiency going forward. In 2023, we substantially completed all construction for this project.

Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed, and therefore, we do not have the project asset or related obligation recorded on our balance sheets, except for certain assets recorded as leasehold improvements within property and equipment, net on our balance sheets.

We have recorded approximately $200 million as a ROU asset on our balance sheets related to certain costs incurred in excess of RAIC funding, though we have not recognized a ROU asset and lease liability on our balance sheets for the variable lease payments in our agreement with the City. See Note 7, "Leases" for more information on our ROU assets and lease liabilities.

New York-LaGuardia Airport

As part of the terminal redevelopment project at LaGuardia Airport, we are partnering with the Port Authority to replace Terminals C and D with a new state-of-the-art terminal facility consisting of 37 gates across four concourses connected to a central headhouse. The completed terminal redevelopment features a new, larger Delta Sky Club, wider concourses, more gate seating and nearly double the amount of concessions space than the prior terminals. The completed facility also offers direct access between the parking garage and terminal and improved roadways and drop-off/pick-up areas. Construction is underway and is being phased to limit passenger inconvenience.

We have opened Concourse E, Concourse G, the headhouse (including the Delta Sky Club), the terminal roadways and portions of Concourse D and Concourse F. Due to an acceleration effort that commenced in 2020, substantial completion is expected by the end of 2024.
In connection with the redevelopment, during 2017, we entered into an amended and restated terminal lease with the Port Authority with a term through 2050. Pursuant to the lease agreement, as amended to date, we (1) are funding (through debt issuance and existing cash) and undertaking the design, management and construction of the terminal and certain off-premises supporting facilities, (2) are receiving a Port Authority contribution of approximately $500 million to facilitate construction of the terminal and other supporting infrastructure, (3) will be responsible for all operations and maintenance during the term of the lease and (4) will have preferential rights to all gates in the terminal subject to Port Authority requirements with respect to accommodation of designated carriers.

The project is expected to cost $4.3 billion and the total amount spent to date is approximately $3.7 billion. We currently expect our net project cost to be approximately $3.8 billion and we bear the risks of project construction, including any potential cost over-runs. We entered into loan agreements to fund a portion of the construction, which are recorded on our balance sheets as debt with the proceeds reflected as restricted cash. Using funding primarily provided by these arrangements, we spent approximately $500 million, $650 million and $950 million during 2023, 2022 and 2021, respectively. Based on our assessment of the project, we concluded that we do not control the underlying assets being constructed. Costs incurred by Delta are accounted for as leasehold improvements recorded in property and equipment, net on our balance sheets. See Note 6, "Debt," for additional information on the debt (NYTDC Special Facilities Revenue Bonds) related to this redevelopment project.
v3.24.0.1
EMPLOYEE BENEFIT PLANS
 12 Months Ended
Dec. 31, 2023
Retirement Benefits [Abstract]  
EMPLOYEE BENEFIT PLANS EMPLOYEE BENEFIT PLANS
We sponsor defined benefit and defined contribution pension plans, healthcare plans and disability and survivorship plans for eligible employees and retirees and their eligible family members.

Defined Benefit Pension Plans. We sponsor defined benefit pension plans for eligible employees and retirees. These plans are generally closed to new entrants and frozen for future benefit accruals. Our funding obligations for qualified defined benefit plans are governed by the Employee Retirement Income Security Act and any applicable legislation. Under the Pension Protection Act of 2006, we elected alternative funding rules so that the unfunded liability for a frozen defined benefit plan may be amortized over a fixed 17-year period and is calculated using an 8.85% discount rate until the 17-year period expires for all frozen defined benefit plans by the end of 2024. Upon expiration, under legislation passed in 2021, any required funding would be amortized over a rolling 15-year period and calculated using a discount rate of no less than 4.75% through 2030. We have no minimum funding requirements for these plans in 2024 and do not plan to make voluntary contributions during 2024.

During 2023, we established a market based cash balance defined benefit pension plan for eligible pilots that is funded by company contributions in excess of IRS limits in the 401(k) plan. Prior to 2023, these contributions were reflected in our cost associated with the defined contribution pension plans shown below. The company funds the plan with cash contributions as benefits are earned and invests those assets. The participants’ benefit is the sum of the contributions made on their behalf plus any positive return on the invested contributions.

Defined Contribution Pension Plans. We sponsor several defined contribution plans. These plans generally cover different employee groups and employer contributions vary by plan. The costs associated with our defined contribution pension plans were approximately $1.2 billion, $1.0 billion and $875 million for the years ended December 31, 2023, 2022 and 2021, respectively.

Postretirement Healthcare Plans. We sponsor healthcare plans that provide benefits to eligible retirees and their dependents who are under age 65. We have generally eliminated company-paid post age 65 healthcare coverage, except for (1) subsidies available to a limited group of retirees and their dependents, (2) a group of retirees who retired prior to 1987 and (3) retiree medical accounts which provide a fixed dollar amount to eligible employees who retired under the 2012 voluntary workforce reduction programs or under the 2020 voluntary early retirement and separation programs ("voluntary programs").

Postemployment Plans. We provide certain other welfare benefits to eligible former or inactive employees after employment but before retirement, primarily as part of the disability and survivorship plans. Substantially all employees are eligible for benefits under these plans in the event of death and/or disability.

Benefits under our postretirement and post employment plans are funded from current assets and employee contributions.
Benefit Obligations, Fair Value of Plan Assets and Funded Status
Pension BenefitsOther Postretirement and Postemployment Benefits
December 31,December 31,
(in millions)2023202220232022
Benefit obligation at beginning of period$15,811 $21,073 $3,664 $4,605 
Service cost95 — 71 70 
Interest cost855 611 200 128 
Actuarial loss/(gain)351 (4,599)24 (710)
Benefits paid, including lump sums and annuities(1,201)(1,274)(485)(447)
Plan amendments— — 11 — 
Participant contributions— — 18 18 
Benefit obligation at end of period(1)
$15,911 $15,811 $3,503 $3,664 
Fair value of plan assets at beginning of period$15,721 $19,502 $71 $357 
Actual gain/(loss) on plan assets1,142 (2,517)3 (73)
Employer contributions104 10 426 216 
Participant contributions— — 18 18 
Benefits paid, including lump sums and annuities(1,201)(1,274)(485)(447)
Fair value of plan assets at end of period$15,766 $15,721 $33 $71 
Funded status at end of period$(145)$(90)$(3,470)$(3,593)
(1) At the end of each year presented, our accumulated benefit obligations for our pension plans are equal to the benefit obligations shown above.

During 2023, net actuarial losses increased our benefit obligation primarily due to the decrease in discount rates while net actuarial gains decreased our benefit obligation primarily due to the increase in discount rates during 2022. These gains and losses are recorded in AOCI and reflected in the table below. Amounts are generally amortized from AOCI over the expected future lifetime of plan participants.

Balance Sheet Position
Pension BenefitsOther Postretirement and Postemployment Benefits
December 31,December 31,
(in millions)2023202220232022
Prepaid pension assets$22 $27 $— $— 
Current liabilities(9)(9)(404)(369)
Noncurrent liabilities(158)(108)(3,066)(3,224)
Funded status at end of period$(145)$(90)$(3,470)$(3,593)
Net actuarial (loss)/gain$(6,474)$(6,444)$(162)$(155)
Prior service credit— — 1 18 
Total accumulated other comprehensive loss, pre-tax$(6,474)$(6,444)$(161)$(137)

Certain pension plans have benefit obligations in excess of plan assets. These plans have aggregate projected benefit obligations of $8.6 billion and aggregate fair value of plan assets of $8.4 billion at December 31, 2023.
Net Periodic Cost/(Benefit)
Pension BenefitsOther Postretirement and Postemployment Benefits
Year Ended December 31,Year Ended December 31,
(in millions)202320222021202320222021
Service cost$95 $— $— $71 $70 $86 
Interest cost855 611 582 200 128 117 
Expected return on plan assets(1,060)(1,319)(1,522)(1)(17)(34)
Amortization of prior service credit— — — (5)(5)(6)
Recognized net actuarial loss240 255 354 14 56 55 
Settlements— — 2 — — — 
Net periodic cost/(benefit)
$130 $(453)$(584)$279 $232 $218 

Service cost is recorded in salaries and related costs in the income statement, while all other components are recorded within pension and related (expense)/benefit under non-operating expense. Service cost listed under Pension Benefits relates solely to the new market based cash balance defined benefit pension plan discussed above.

Assumptions

We used the following actuarial assumptions to determine our benefit obligations and our net periodic cost/(benefit) for the periods presented:
December 31,
Benefit Obligations(1)
20232022
Weighted average discount rate5.31 %5.62 %

Year Ended December 31,
Net Periodic Cost/(Benefit)(1)
202320222021
Weighted average discount rate5.59 %2.96 %2.61 %
Weighted average expected long-term rate of return on plan assets7.00 %7.00 %8.98 %
Assumed healthcare cost trend rate for the next year(2)
6.25 %6.50 %6.25 %
(1)Future employee compensation levels do not impact our frozen defined benefit pension plans or other postretirement plans and impact only a small portion of our other postemployment obligation.
(2)Healthcare cost trend rate is assumed to decline gradually to 5.00% by 2029 and remain unchanged thereafter.

Expected Long-Term Rate of Return. Our expected long-term rate of return on plan assets is based primarily on plan-specific investment studies using historical market return and volatility data. Modest excess return expectations versus some public market indices are incorporated into the return projections based on the actively managed structure of the investment programs and their records of achieving such returns historically. We also expect to receive a premium for investing in less liquid private markets. We review our rate of return on plan assets assumptions annually. Our annual investment performance for one particular year does not, by itself, significantly influence our evaluation. The investment strategy for our defined benefit pension plan assets is to earn a long-term return that meets or exceeds our annualized return target while taking an acceptable level of risk and maintaining sufficient liquidity to pay current benefits and other cash obligations of the plan. This is achieved by investing in a globally diversified mix of public and private equity, fixed income, real assets, hedge funds and other assets and instruments. Our weighted average expected long-term rate of return on assets for net periodic cost/(benefit) for the year ended December 31, 2023 was 7.00%.

Life Expectancy. Changes in life expectancy may significantly impact our benefit obligations and future net periodic cost/(benefit). Each year we review information published by the Society of Actuaries and other publicly available information to develop our best estimate of life expectancy for purposes of measuring pension and other postretirement and postemployment benefit obligations.
Benefit Payments

Benefit payments in the table below are based on the same assumptions used to measure the related benefit obligations. Actual benefit payments may vary significantly from these estimates. Benefits earned under our pension plans are expected to be paid from funded benefit plan trusts, while our other postretirement and postemployment benefits are funded from current assets.

The following table summarizes the benefit payments that are expected to be paid in the years ending December 31:

Expected future benefit payments
(in millions)Pension BenefitsOther Postretirement and Postemployment Benefits
2024$1,310 $450 
20251,350 440 
20261,350 440 
20271,360 440 
20281,360 450 
2029-20336,670 2,190 

Plan Assets

We have adopted and implemented investment policies for our defined benefit pension plans that incorporate strategic asset allocation mixes intended to best meet the plans' long-term obligations, while maintaining an appropriate level of risk and liquidity. These asset portfolios employ a diversified mix of investments, which are reviewed periodically. Active management strategies are utilized where feasible in an effort to realize investment returns in excess of market indices. Derivatives in the plans are primarily used to manage risk and gain asset class exposure while still maintaining liquidity. As part of these strategies, the plans are required to hold cash collateral associated with certain derivatives. Our investment strategies target a mix of 20-40% growth-seeking assets, 25-35% income-generating assets and 35-45% risk-diversifying assets. Risk diversifying assets include hedge funds implementing long-short, market neutral and relative value strategies that invest primarily in publicly-traded equity, fixed income, foreign currency and commodity securities and are used to improve the impact of active management on the plans.

Benefit Plan Assets Measured at Fair Value on a Recurring Basis

Benefit plan assets relate to our defined benefit pension plans and certain of our postemployment benefit plans. These investments are presented net of the related benefit obligation in either other noncurrent assets or pension, postretirement and related benefits on the balance sheets depending on the funded status of each plan. See Note 3, "Fair Value Measurements," for a description of the levels within the fair value hierarchy and associated valuation techniques used to measure fair value. The following table shows our benefit plan assets by asset class.

Benefit plan assets measured at fair value on a recurring basis
December 31, 2023December 31, 2022Valuation Technique
(in millions)Level 1Level 2TotalLevel 1Level 2Total
Fixed income and fixed income-related instruments$300 $1,858 $2,158 $77 $1,366 $1,443 (a)(b)
Cash equivalents471 685 1,156 629 265 894 (a)
Equities and equity-related instruments647 122 769 420 25 445 (a)
Delta common stock419 — 419 343 — 343 (a)
Real assets11 236 247 17 170 187 (a)
Benefit plan assets$1,848 $2,901 $4,749 $1,486 $1,826 $3,312 
Investments measured at net asset value ("NAV")(1)
11,417 12,329 
Total benefit plan assets$16,166 $15,641 
(1) Investments that were measured at NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy.
Fixed Income and Fixed Income-Related Instruments. These investments include corporate bonds, government bonds, collateralized mortgage obligations and other asset-backed securities, and are generally valued at the bid price or the average of the bid and ask price. Prices are based on pricing models, quoted prices of securities with similar characteristics or broker quotes. Fixed income-related instruments include investments in securities traded on exchanges, including listed futures and options, which are valued at the last reported sale prices on the last business day of the year, or if not available, the last reported bid prices. Over-the-counter securities are valued at the bid prices or the average of the bid and ask prices on the last business day of the year from published sources or, if not available, from other sources considered reliable, generally broker quotes.

Cash Equivalents. These investments primarily consist of high-quality, short-term obligations that are a part of institutional money market mutual funds that are valued using current market quotations or an appropriate substitute that reflects current market conditions.

Equities and Equity-Related Instruments. These investments include common stock and equity-related instruments. Common stock is valued at the closing price reported on the active market on which the individual securities are traded. Equity-related instruments include investments in securities traded on exchanges, including listed futures and options, which are valued at the last reported sale prices on the last business day of the year or, if not available, the last reported bid prices. Over-the-counter securities are valued at the bid prices or the average of the bid and ask prices on the last business day of the year from published sources or, if not available, from other sources considered reliable, generally broker quotes.

Delta Common Stock. The Delta common stock investment is managed by an independent fiduciary.

Real Assets. These investments include commodities such as precious metals and precious metals-related instruments, some of which are valued at the closing price reported on the active market on which the individual instruments are traded, while others are priced based on pricing models, quoted prices of securities with similar characteristics or broker quotes.

The following table summarizes investments measured at fair value based on NAV per share as a practical expedient:

Benefit plan investment assets measured at NAV
December 31, 2023December 31, 2022
(in millions)Fair ValueRedemption FrequencyRedemption Notice PeriodFair ValueRedemption FrequencyRedemption Notice Period
Hedge funds and hedge fund-related strategies$6,175 (1)
7-180 Days
$6,730 (1)
2-180 Days
Commingled funds, private equity and private equity-related instruments (4)
2,379 (1) (2)
0-45 Days
2,266 (1) (2)
2-45 Days
Fixed income and fixed income-related instruments(4)
1,147 (1)
1-180 Days
1,003 (1)
1-180 Days
Real assets (4)
893 (2)N/A819 (2)N/A
Other823 (3)
2-10 Days
1,511 (3)
2-10 Days
Total investments measured at NAV$11,417 $12,329 
(1)Various. Includes funds with monthly or more frequent, quarterly and/or custom redemption frequencies as well as funds with a redemption window following the anniversary of the initial investment.
(2)Includes private funds that are closed-ended structures in which the plans' investments are generally not eligible for redemption.
(3)Includes funds with monthly or more frequent redemptions.
(4)Unfunded commitments were $1.3 billion for commingled funds, private equity and private equity-related instruments, $296 million for fixed income and fixed income-related instruments and $584 million for real assets at December 31, 2023.

On an annual basis we assess the potential for adjustments to the fair value of all investments. This primarily applies to private equity, private equity-related strategies and real assets. Due to a lag in the availability of data for certain of these investments, we solicit valuation updates from the investment fund managers and use their information and corroborating data from public markets to determine any needed fair value adjustments.

Hedge Funds and Hedge Fund-Related Strategies. These investments are primarily made through shares of limited partnerships or similar structures for which a liquid secondary market does not exist.

Commingled Funds, Private Equity and Private Equity-Related Instruments. These investments include commingled funds invested in common stock, as well as private equity and private equity-related instruments. Commingled funds are valued based on quoted market prices of the underlying assets owned by the fund. Private equity and private equity-related instruments are typically valued quarterly by the fund managers using valuation models where one or more of the significant inputs into the model cannot be observed and which require the development of assumptions.
Fixed Income and Fixed Income-Related Instruments. These investments include private fixed income instruments that are typically valued monthly or quarterly by the fund managers or third-party valuation agents using valuation models where one or more of significant inputs into the model cannot be observed and which require the development of assumptions.

Real Assets. These investments include real estate, energy transition, timberland, agriculture and infrastructure. The valuation of real assets requires significant judgment due to the absence of quoted market prices as well as the inherent lack of liquidity and the long-term nature of these assets. Real assets are typically valued quarterly by the fund managers using valuation models where one or more of the significant inputs into the model cannot be observed and which require the development of assumptions.

Other. Primarily includes globally-diversified, risk-managed commingled funds consisting mainly of equity, fixed income and commodity exposures.

Other

We also sponsor defined benefit pension plans for eligible employees in certain foreign countries. These plans did not have a material impact on our Consolidated Financial Statements in any period presented.

Profit Sharing Program

Our broad-based employee profit sharing program provides that, for each year in which we have an annual pre-tax profit, as defined by the terms of the program, we will pay a specified portion of that profit to employees. In determining the amount of profit sharing, the program defines profit as pre-tax profit adjusted for profit sharing and certain other items.
For the years ended December 31, 2023 and 2022, we recorded profit sharing expense of $1.4 billion and $563 million under the program, respectively. For the year ended December 31, 2021, we recorded a special profit sharing expense of $108 million, based on the adjusted pre-tax profit earned during the second half of the year, to recognize the extraordinary efforts of our employees through the pandemic.
v3.24.0.1
COMMITMENTS AND CONTINGENCIES
 12 Months Ended
Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]  
COMMITMENTS AND CONTINGENCIES COMMITMENTS AND CONTINGENCIES
Aircraft Purchase Commitments

Our future aircraft purchase commitments totaled approximately $17.5 billion at December 31, 2023:

Aircraft purchase commitments(1)
(in millions)Total
2024$3,530 
20254,230 
20263,490 
20273,870 
20281,650 
Thereafter760 
Total$17,530 
(1)The timing of these commitments is based on our contractual agreements with the aircraft manufacturers and remains uncertain due to supply chain, manufacturing and regulatory constraints.
Our future aircraft purchase commitments included the following aircraft at December 31, 2023:

Aircraft purchase commitments by fleet type
Fleet TypePurchase Commitments
A220-30077 
A321-200neo107 
A330-900neo12 
A350-90016 
B-737-10100 
Total312 

Aircraft Orders

During 2023, we agreed to acquire one A330-900 with delivery expected to occur in 2025 and exercised purchase rights for 26 A220-300 aircraft with delivery expected to start in 2027.

In January 2024, we entered into a purchase agreement with Airbus for 20 A350-1000 aircraft, with an option to purchase an additional 20 widebody aircraft. Deliveries of these aircraft are scheduled to begin in 2026.

Contract Carrier Agreements

We have contract carrier agreements with regional carriers expiring through 2034. These agreements are structured as either capacity purchase or revenue proration agreements.

Capacity Purchase Agreements. Our regional carriers primarily operate for us under capacity purchase agreements. Under these agreements, the regional carriers operate some or all of their aircraft using our flight designator codes, and we control the scheduling, pricing, reservations, ticketing and seat inventories of those aircraft and retain the revenues associated with those flights. We pay those airlines an amount, as defined in the applicable agreement, which is based on a determination of their cost of operating those flights and other factors intended to approximate market rates for those services.

The following table shows our minimum obligations under our existing capacity purchase agreements with third-party regional carriers, excluding contract carrier payments accounted for as leases of aircraft, which are described in Note 7, "Leases." The obligations set forth in the table contemplate minimum levels of flying by the regional carriers under the respective agreements and also reflect assumptions regarding certain costs associated with the minimum levels of flying such as the cost of fuel, labor, maintenance, insurance, catering, property tax and landing fees. Accordingly, our actual payments under these agreements could differ materially from the minimum fixed obligations set forth in the table below.

Contract carrier minimum obligations
(in millions)Amount
2024$1,600 
20251,540 
20261,560 
20271,520 
20281,260 
Thereafter1,360 
Total$8,840 

Revenue Proration Agreement. As of December 31, 2023, a portion of our contract carrier arrangement with SkyWest Airlines, Inc. was structured as a revenue proration agreement. This revenue proration agreement establishes a fixed dollar or percentage division of revenues for tickets sold to passengers traveling on connecting flight itineraries.
Legal Contingencies

We are involved in various legal proceedings related to employment practices, environmental issues, commercial disputes, antitrust and other regulatory matters concerning our business. We record liabilities for losses from legal proceedings when we determine that it is probable that the outcome in a legal proceeding will be unfavorable and the amount of loss can be reasonably estimated. Although the outcome of the legal proceedings in which we are involved cannot be predicted with certainty, we believe that the resolution of current matters will not have a material adverse effect on our Consolidated Financial Statements.

Credit Card Processing Agreements

Our VISA/MasterCard and American Express credit card processing agreements provide that no cash reserve ("Reserve") is required, and no withholding of payment related to receivables collected will occur, except in certain circumstances, including when we do not maintain a required level of liquidity as outlined in the merchant processing agreements. In circumstances in which the credit card processor can establish a Reserve or withhold payments, the amount of the Reserve or payments that may be withheld would be equal to the potential liability of the credit card processor for tickets purchased with VISA/MasterCard or American Express credit cards, as applicable, that had not yet been used for travel. We did not have a Reserve or an amount withheld as of December 31, 2023 or 2022.

Other Contingencies

General Indemnifications

We are the lessee under many commercial real estate leases. It is common in these transactions for us, as the lessee, to agree to indemnify the lessor and the lessor's related parties for tort, environmental and other liabilities that arise out of or relate to our use or occupancy of the leased premises. This type of indemnity would typically make us responsible to indemnified parties for liabilities arising out of the conduct of, among others, contractors, licensees and invitees at, or in connection with, the use or occupancy of the leased premises. This indemnity often extends to related liabilities arising from the negligence of the indemnified parties, but usually excludes any liabilities caused by either their sole or gross negligence or their willful misconduct.

Our aircraft and other equipment lease and financing agreements typically contain provisions requiring us, as the lessee or obligor, to indemnify the other parties to those agreements, including certain of those parties' related persons, against virtually any liabilities that might arise from the use or operation of the aircraft or other equipment.

We believe that our insurance would cover most of our exposure to liabilities and related indemnities associated with the commercial real estate leases and aircraft and other equipment lease and financing agreements described above. While our insurance does not typically cover environmental liabilities, we have insurance policies in place as required by applicable environmental laws.

Some of our aircraft and other financing transactions include provisions that require us to make payments to preserve an expected economic return to the lenders if that economic return is diminished due to specified changes in law or regulations. In some of these financing transactions, we also bear the risk of changes in tax laws that would subject payments to non-U.S. lenders to withholding taxes.

We cannot reasonably estimate our potential future payments under the indemnities and related provisions described above because we cannot predict (1) when and under what circumstances these provisions may be triggered and (2) the amount that would be payable if the provisions were triggered because the amounts would be based on facts and circumstances existing at such time.
Employees Under Collective Bargaining Agreements

As of December 31, 2023, we had approximately 103,000 full-time equivalent employees, approximately 20% of whom were represented by unions.

Domestic airline employees represented by collective bargaining agreements by group
Employee GroupApproximate Number of
Employees Represented		UnionDate on which Collective
Bargaining Agreement
Becomes Amendable
Delta Pilots16,960 ALPADecember 31, 2026
Delta Flight Superintendents (Dispatchers)
490 PAFCANovember 1, 2024
Endeavor Pilots1,530 ALPAJanuary 1, 2029
Endeavor Flight Attendants
1,600 AFAMarch 31, 2027

Delta pilots ratified a new four-year Pilot Working Agreement effective January 1, 2023. The agreement includes numerous work rule changes and pay rate increases during the four-year term, including an initial pay rate increase of 18%. The agreement also includes a provision for a one-time payment made upon ratification in the March 2023 quarter of $735 million. Additionally, we recorded adjustments to other benefit-related items of approximately $130 million. These items are recorded within pilot agreement and related expenses in our income statement.

In addition to the domestic airline employee groups discussed above, approximately 200 refinery employees of our wholly owned subsidiary Monroe are represented by the United Steel Workers under an agreement that expires on February 28, 2026. This agreement is governed by the National Labor Relations Act, which generally allows either party to engage in self-help upon the expiration of the agreement. Certain of our employees outside the U.S. are represented by unions, work councils or other local representative groups.
Other

We have certain contracts for goods and services that require us to pay a penalty, acquire inventory specific to us or purchase contract-specific equipment, as defined by each respective contract, if we terminate the contract without cause prior to its expiration date. Because these obligations are contingent on our termination of the contract without cause prior to its expiration date, no obligation would exist unless such a termination occurs.
v3.24.0.1
INCOME TAXES
 12 Months Ended
Dec. 31, 2023
Income Tax Disclosure [Abstract]  
INCOME TAXES INCOME TAXES
Income Tax Provision

Components of income tax provision
Year Ended December 31,
(in millions)202320222021
Current tax provision:
Federal$— $— $— 
State and local(8)(1)(1)
International(11)(4)(3)
Deferred tax (provision) benefit:
Federal(896)(525)(130)
State and local(84)(66)16 
Income tax provision$(999)$(596)$(118)
The following table presents the principal reasons for the difference between the effective tax rate and the U.S. federal statutory income tax rate:

Reconciliation of statutory federal income tax rate to the effective income tax rate
Year Ended December 31,
202320222021
U.S. federal statutory income tax rate21.0 %21.0 %21.0 %
State taxes, net of federal benefit2.0 3.0 (4.4)
Permanent differences0.7 1.0 4.9 
Valuation allowance(5.0)7.3 9.1 
Other(0.9)(1.1)(0.8)
Effective income tax rate17.8 %31.2 %29.8 %

Deferred Taxes

Deferred income taxes reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes.

Significant components of deferred income tax assets and liabilities
December 31,
(in millions)20232022
Deferred tax assets:
Net operating loss carryforwards$1,217 $1,395 
Capital loss carryforward8 50 
Pension, postretirement and other benefits1,488 1,467 
Investments806 1,106 
Deferred revenue2,110 2,334 
Lease liabilities2,193 2,376 
Other709 682 
Valuation allowance(877)(1,176)
Total deferred tax assets$7,654 $8,234 
Deferred tax liabilities:
Depreciation$5,570 $5,110 
Operating lease assets1,533 1,624 
Intangible assets1,143 1,121 
Other73 78 
Total deferred tax liabilities$8,319 $7,933 
Balance Sheet Position:
Other noncurrent assets$243 $325 
Deferred income taxes, net(908)(24)
Net deferred tax (liabilities) assets
$(665)$301 

Valuation Allowance

We periodically assess whether it is more likely than not that we will generate sufficient taxable income to realize our deferred income tax assets. We establish valuation allowances if it is more likely than not that we will be unable to realize our deferred income tax assets. In making this determination, we consider available positive and negative evidence and make certain assumptions. We consider, among other things, projected future taxable income, scheduled reversals of deferred tax liabilities, the overall business environment, our historical financial results and tax planning strategies.
At December 31, 2023 our net deferred tax liability balance was $665 million, including an $877 million valuation allowance primarily related to certain net realized and unrealized capital losses and certain state net operating losses.

As of December 31, 2023, we had approximately $4.5 billion of U.S. federal pre-tax net operating loss carryforwards which we are expecting to utilize by the end of 2025. Approximately $800 million of these net operating loss carryforwards were generated prior to 2018 and will not begin to expire until 2029, while the remaining net operating loss carryforwards do not expire. Therefore, we have not recorded a valuation allowance on our deferred tax assets other than the certain net realized and unrealized capital losses and certain state net operating losses that have short expiration periods.

The following table presents the balance of our valuation allowance on our deferred income tax assets and the associated activity:

Valuation allowance activity
(in millions)20232022
Balance at January 1$1,176 $833 
Tax provision(299)155 
Equity investment activity— 188 
Balance at December 31$877 $1,176 

Other

The amount of, and changes to, our uncertain tax positions were not material in any of the years presented. We are currently under audit by the IRS for the 2023 and 2022 tax years.
v3.24.0.1
EQUITY AND EQUITY COMPENSATION
 12 Months Ended
Dec. 31, 2023
Equity [Abstract]  
EQUITY AND EQUITY COMPENSATION EQUITY AND EQUITY COMPENSATION
Equity

We are authorized to issue 2.0 billion shares of capital stock, of which up to 1.5 billion may be shares of common stock, par value $0.0001 per share, and up to 500 million may be shares of preferred stock.

Preferred Stock. We may issue preferred stock in one or more series. The Board of Directors is authorized (1) to fix the descriptions, powers (including voting powers), preferences, rights, qualifications, limitations and restrictions with respect to any series of preferred stock and (2) to specify the number of shares of any series of preferred stock. We have not issued any preferred stock.

Treasury Stock. We generally withhold shares of Delta common stock to cover employees' portion of required tax withholdings when employee equity awards are issued or vest. These shares are valued at cost, which equals the market price of the common stock on the date of issuance or vesting. The weighted average cost per share held in treasury was $30.37 and $29.73 as of December 31, 2023 and 2022, respectively.

Warrants. During 2020 and 2021, in connection with the Coronavirus Aid, Relief, and Economic Security Act of 2020 (the "CARES Act") payroll support program ("PSP") and extensions, we issued warrants to the U.S Department of the Treasury to acquire more than 11.1 million shares of Delta common stock. The number of warrants outstanding slightly increased and the exercise price of the warrants slightly decreased since December 31, 2022 due to dividend payments during 2023. Key terms under each program as of December 31, 2023 are as follows:

Summary of payroll support program warrants
(in millions)Number of WarrantsExercise PriceExpiration Year
Payroll Support Program (PSP1)6.8$24.25 2025
Payroll Support Program Extension (PSP2)2.439.54 2026
Payroll Support Program 3 (PSP3)1.947.57 2026
Total11.1
Government Grant Recognition. Under the initial payroll support program under the CARES Act and PSP extensions we received support payments of grants, which included $4.5 billion of grants during the year ended December 31, 2021. The grants received from PSP2 and PSP3 were recognized in government grant recognition in our income statement during 2021 over the period that the funds were intended to compensate.

Equity Compensation

Our broad-based equity and cash compensation plan provides for grants of restricted stock, restricted stock units, stock options, performance awards, including cash incentive awards and other equity-based awards (the "Plan"). Shares of common stock issued under the Plan may be made available from authorized, but unissued, common stock or common stock we acquire. If any shares of our common stock are covered by an award that expires, is canceled, forfeited or otherwise terminates without delivery of shares (including shares surrendered or withheld for payment of taxes related to an award), such shares will again be available for issuance under the Plan except for (1) any shares tendered in payment of an option, (2) shares withheld to satisfy any tax withholding obligation with respect to the exercise of an option or stock appreciation right ("SAR") or (3) shares covered by a stock-settled SAR or other awards that were not issued upon the settlement of the award. The Plan authorizes the issuance of up to 163 million shares of common stock. As of December 31, 2023, there were 13 million shares available for future grants.

We make long-term incentive awards annually to eligible employees under the Plan. Generally, awards vest over time, subject to the employee's continued employment. Equity compensation expense, including awards payable in common stock or cash, is recognized in salaries and related costs over the employee's requisite service period (generally, the vesting period of the award) and totaled $180 million, $150 million and $149 million for the years ended December 31, 2023, 2022 and 2021, respectively. We record expense on a straight-line basis for awards with installment vesting. As of December 31, 2023, unrecognized costs related to unvested shares and stock options totaled $103 million. We expect substantially all unvested awards to vest and recognize forfeitures as they occur.

Restricted Stock. Restricted stock is common stock that may not be sold or otherwise transferred for a period of time and is subject to forfeiture in certain circumstances. The fair value of restricted stock awards is based on the closing price of the common stock on the grant date. As of December 31, 2023, there were 4.2 million unvested restricted stock awards. Restricted stock activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows:

Restricted Stock Award Activity
202320222021
Restricted
Stock Awards		Weighted-Average
Grant Price		Restricted
Stock Awards		Weighted-Average
Grant Price		Restricted
Stock Awards		Weighted-Average
Grant Price
(in millions, except weighted avg grant price)
Outstanding at January 13.1 $43.43 2.9 $45.66 2.2 $54.06 
Granted2.7 39.63 1.9 42.45 2.3 39.93 
Vested(1.5)44.79 (1.6)46.31 (1.4)51.15 
Forfeited(0.1)40.94 (0.1)45.51 (0.2)44.01 
Outstanding at December 314.2 $40.51 3.1 $43.43 2.9 $45.66 
Stock Options. Stock options are granted with an exercise price equal to the closing price of Delta common stock on the grant date and generally have a 10-year term. We determine the fair value of stock options at the grant date using an option pricing model. As of December 31, 2023, there were 6.2 million outstanding stock option awards with a weighted average exercise price of $50.42 of which 5.9 million were exercisable. Stock option activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows:

Stock Option Activity
202320222021
Stock OptionsWeighted-Average
Exercise Price		Stock OptionsWeighted-Average
Exercise Price		Stock OptionsWeighted-Average
Exercise Price
(in millions, except weighted avg grant price)
Outstanding at January 16.2 $50.40 6.2 $50.41 5.4 $52.37 
Granted— — — — 1.0 39.78 
Exercised(1)
— 39.78 — — — — 
Forfeited(1)
— 51.91 — 52.87 (0.2)49.61 
Outstanding at December 316.2 $50.42 6.2 $50.40 6.2 $50.41 
(1)2023 exercise and forfeiture and 2022 forfeiture activity in the table above rounds to zero.

Performance Awards. Performance awards are dollar-denominated long-term incentive opportunities which, for grants prior to 2021, were payable in Delta stock to executive officers on the payment date and in cash to all other participants. Beginning with the 2021 grants, performance awards are payable in cash to all participants. Potential performance award payments range from 0%-200% of a target level and are contingent upon our achieving certain financial and operational goals over a three-year performance period. As of December 31, 2023, there were no performance awards payable in Delta stock to executive officers. Based on the closing stock price at each respective year end and contingent on achieving the specified performance conditions, the maximum shares that could be issued were 0.7 million and 1.5 million for the years ended December 31, 2022 and 2021, respectively.

Performance-Based Restricted Stock Units. Performance-based restricted stock units are long-term incentive opportunities that provide executive officers with the right to receive shares of Delta stock based on our achievement of certain performance conditions at the end of a three-year period. Potential payouts range from 0%-300% of a target level. Based on the closing stock price at year end and contingent on achieving the specified performance conditions, the maximum shares that could be issued were 3.3 million and 1.3 million for the years ended December 31, 2023 and 2022, respectively. There were no outstanding performance-based restricted stock units for the year ended December 31, 2021.
v3.24.0.1
ACCUMULATED OTHER COMPREHENSIVE LOSS
 12 Months Ended
Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]  
ACCUMULATED OTHER COMPREHENSIVE LOSS ACCUMULATED OTHER COMPREHENSIVE LOSS
Components of accumulated other comprehensive loss
(in millions)
Pension and Other Benefits Liabilities(2)
OtherTax EffectTotal
Balance at January 1, 2021$(10,843)$41 $1,764 $(9,038)
Changes in value2,077 — (484)1,593 
Reclassifications into earnings(1)
411 — (96)315 
Balance at December 31, 2021
(8,355)41 1,184 (7,130)
Changes in value1,419 — (330)1,089 
Reclassifications into earnings(1)
312 — (72)240 
Balance at December 31, 2022
(6,624)41 782 (5,801)
Changes in value(303)(1)71 (233)
Reclassifications into earnings(1)
246 — (57)189 
Balance at December 31, 2023
$(6,681)$40 $796 $(5,845)
(1)Amounts reclassified from AOCI for pension and other benefits liabilities are recorded in pension and related (expense)/benefit in non-operating expense in the income statement.
(2)Includes approximately $755 million of deferred income tax expense as a result of tax law changes and prior valuation allowance releases through continuing operations, that will not be recognized in net income until pension and other benefit obligations are fully extinguished.
v3.24.0.1
SEGMENTS
 12 Months Ended
Dec. 31, 2023
Segment Reporting [Abstract]  
SEGMENTS SEGMENTS
Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker and is used in resource allocation and performance assessments. Our chief operating decision maker is considered to be our executive leadership team. Our executive leadership team regularly reviews discrete information for our two operating segments, which are determined by the products and services provided: our airline segment and our refinery segment.

Airline Segment

Our airline segment is managed as a single business unit that provides scheduled air transportation for passengers and cargo throughout the U.S. and around the world and includes our loyalty program, as well as other ancillary businesses. This allows us to benefit from an integrated revenue pricing and route network. Our flight equipment forms one fleet, which is deployed through a single route scheduling system. When making resource allocation decisions, our chief operating decision maker evaluates flight profitability data, which considers fleet type and route economics, but gives no weight to the financial impact of the resource allocation decision on a geographic region or mainline/regional carrier basis. Our objective in making resource allocation decisions is to optimize our consolidated financial results.

Refinery Segment

Our Monroe subsidiary operates the Trainer oil refinery and related assets located near Philadelphia, Pennsylvania, as part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel. Monroe's operations include pipelines and terminal assets that allow the refinery to supply jet fuel to our airline operations throughout the Northeastern U.S., including our New York hubs at LaGuardia and JFK.

Our refinery segment operates for the benefit of the airline segment by providing jet fuel to the airline segment from its own production and through jet fuel obtained through agreements with third parties. The refinery's production consists of jet fuel, as well as non-jet fuel products. We use several counterparties to exchange the non-jet fuel products produced by the refinery for jet fuel consumed in our airline operations. The gross fair value of the products exchanged under these agreements during the years ended December 31, 2023, 2022 and 2021 was $2.4 billion, $3.5 billion and $2.3 billion, respectively.

A refinery is subject to annual Environmental Protection Agency ("EPA") requirements to blend renewable fuels into the gasoline and on-road diesel fuel it produces. A refinery may meet its obligation by blending the necessary volumes of renewable fuels, by purchasing Renewable Identification Numbers ("RINs") in the open market or through a combination of blending and purchasing RINs. Because Monroe is able to blend only a small amount of renewable fuels, it must purchase the majority of its RINs requirement in the secondary market. Renewable fuel compliance costs are accrued in accounts payable each period as the RINs obligation is generated. Purchased RINs are carried at the lower of cost and net realizable value and are recorded in prepaid expenses and other. During 2023, we acquired RINs assets to satisfy substantially all of our 2023 RINs obligation. The RINs asset and obligation are retired when used to satisfy EPA requirements. During 2023, we retired approximately $700 million of our 2021 and 2022 RINs assets to settle our 2021 and 2022 obligations prior to the compliance deadlines.
Segment Reporting

Segment results are prepared based on our internal accounting methods described below, with reconciliations to consolidated amounts in accordance with GAAP. Our segments are not designed to measure operating income or loss directly related to the products and services included in each segment on a stand-alone basis.

Financial information by segment
(in millions)AirlineRefineryIntersegment Sales/OtherConsolidated
Year Ended December 31, 2023
Operating revenue$54,669 $7,572 $(4,193)
(1)
$58,048 
Depreciation and amortization2,341 94 (94)
(2)
2,341 
Operating income(2)
5,136 385 5,521 
Interest expense, net834 17 (17)834 
Total assets, end of period71,529 2,174 (59)73,644 
Capital expenditures5,088 235 5,323 
Year Ended December 31, 2022
Operating revenue$45,605 $10,706 $(5,729)
(1)
$50,582 
Depreciation and amortization2,107 93 (93)
(2)
2,107 
Operating income(2)
2,884 777 3,661 
Interest expense, net1,029 12 (12)1,029 
Total assets, end of period69,355 3,039 (106)72,288 
Capital expenditures6,217 149 6,366 
Year Ended December 31, 2021
Operating revenue$26,670 $6,054 $(2,825)
(1)
$29,899 
Depreciation and amortization1,998 95 (95)
(2)
1,998 
Operating income/(loss)(2)
1,888 (2)1,886 
Interest expense, net1,279 7 (7)1,279 
Total assets, end of period70,417 2,099 (57)72,459 
Capital expenditures3,188 59 3,247 
(1)See table below for detail of the intersegment operating revenue amounts.
(2)Refinery segment operating results, including depreciation and amortization, are included within aircraft fuel and related taxes in our income statement.

Operating Revenue Intersegment Sales/Other
Year Ended December 31,
(in millions)202320222021
Sales to airline segment(1)
$(1,535)$(1,976)$(492)
Exchanged products(2)
(2,354)(3,475)(2,293)
Sales of refined products
(304)(278)(40)
Total Operating Revenue Intersegment Sales/Other$(4,193)$(5,729)$(2,825)
(1)Represents transfers, valued on a market price basis, from the refinery to the airline segment for use in airline operations. We determine market price for jet fuel from the refinery by reference to the market index for the primary delivery location, which is New York Harbor.
(2)Represents value of products delivered under our exchange agreements, as discussed above, determined on a market price basis.
v3.24.0.1
EARNINGS PER SHARE
 12 Months Ended
Dec. 31, 2023
Earnings Per Share [Abstract]  
EARNINGS PER SHARE EARNINGS PER SHARE
We calculate basic earnings per share by dividing net income by the weighted average number of common shares outstanding, excluding restricted shares. We calculate diluted earnings per share by dividing net income by the weighted average number of common shares outstanding plus the dilutive effect of outstanding share-based instruments, including stock options, restricted stock awards and warrants. Antidilutive common stock equivalents excluded from the diluted earnings per share calculation are not material. The following table shows our computation:

Basic and diluted earnings per share
Year Ended December 31,
(in millions, except per share data)202320222021
Net income$4,609 $1,318 $280 
Basic weighted average shares outstanding639 638 636 
Dilutive effect of share-based instruments4 3 5 
Diluted weighted average shares outstanding643 641 641 
Basic earnings per share$7.21 $2.07 $0.44 
Diluted earnings per share$7.17 $2.06 $0.44 
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
Basis of Presentation
Basis of Presentation

Delta Air Lines, Inc., a Delaware corporation, provides scheduled air transportation for passengers and cargo throughout the United States ("U.S.") and around the world. Our Consolidated Financial Statements include the accounts of Delta Air Lines, Inc. and our consolidated subsidiaries and have been prepared in accordance with generally accepted accounting principles in the U.S. ("GAAP"). We are not the primary beneficiary of, nor do we have a controlling financial interest in, any variable interest entity. Accordingly, we have not consolidated any variable interest entity.

We have marketing alliances with other airlines to enhance our access to domestic and international markets. These arrangements may include codesharing, reciprocal loyalty program benefits, shared or reciprocal access to passenger lounges, joint promotions, common use of airport gates and ticket counters, office co-location and other marketing agreements. We have received antitrust immunity for certain marketing arrangements, which enables us to offer a more integrated route network and develop common sales, marketing and discount programs for customers. Some of our marketing arrangements provide for the sharing of revenues and expenses. Revenues and expenses associated with collaborative arrangements are presented on a gross basis in the applicable line items on our Consolidated Statements of Operations ("income statement").

We have reclassified certain prior period amounts to conform to the current period presentation. Unless otherwise noted, all amounts disclosed are stated before consideration of income taxes.
Use of Estimates
Use of Estimates

We are required to make estimates and assumptions when preparing our Consolidated Financial Statements in accordance with GAAP. These estimates and assumptions affect the amounts reported in our Consolidated Financial Statements and the accompanying notes. Actual results could differ materially from those estimates.
Recent Accounting Standards
Recent Accounting Standards

Standards Effective in Future Years

Fair Value of Equity Investments. In June 2022, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2022-03, "Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions." Under this standard, a contractual restriction on the sale of an equity security is not considered in measuring the security's fair value. The standard also requires certain disclosures for equity securities that are subject to contractual restrictions. The ASU becomes effective January 1, 2024, however we early adopted this standard as of December 31, 2023. The new standard does not impact the valuation of our equity investments, but we have included the newly required disclosures related to the contractual sale restrictions associated with our investment in Wheels Up Experience Inc. ("Wheels Up"). See Note 4, "Investments," for additional details.

Segment Reporting. In November 2023, the FASB issued ASU No. 2023-07, "Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures." This standard requires disclosure of significant segment expenses and other segment items by reportable segment. This ASU becomes effective for annual periods beginning in 2024 and interim periods in 2025. We are assessing the impact of this ASU and upon adoption expect that any impact would be limited to additional segment expense disclosures in the footnotes to our Consolidated Financial Statements.

Income Taxes. In December 2023, the FASB issued ASU No. 2023-09, "Income Taxes (Topic 740): Improvements to Income Tax Disclosures." This standard enhances disclosures related to income taxes, including the rate reconciliation and information on income taxes paid. This ASU becomes effective January 1, 2025. We are assessing the impact of this ASU and upon adoption may be required to include certain additional disclosures in the footnotes to our Consolidated Financial Statements.
Cash and Cash Equivalents Short-term, highly liquid investments with maturities of three months or less when purchased are classified as cash and cash equivalents.
Short-Term Investments Investments with maturities of greater than three months, but not in excess of one year, when purchased are classified as short-term investments and are stated at fair value. Investments with maturities beyond one year when purchased may be classified as short-term investments if they are expected to be available to support our short-term liquidity needs. Our short-term investments in debt securities purchased prior to October 1, 2022 are classified as fair value investments under the fair value option and unrealized gains and losses are recorded in non-operating expense. Our short-term investments in debt securities purchased on or after October 1, 2022 are classified as available-for-sale investments and are stated at fair value with unrealized gains and losses recorded in accumulated other comprehensive income/(loss) ("AOCI"). Realized gains and losses on these investments are recorded in non-operating expense.
Inventories
Inventories

Fuel. As part of our strategy to mitigate the cost of the refining margin reflected in the price of jet fuel, our wholly owned subsidiary, Monroe Energy, LLC ("Monroe"), operates the Trainer oil refinery. Refined products (finished goods) and feedstock and blendstock inventories (work-in-process) are both carried at the lower of cost and net realizable value. We use jet fuel in our airline operations that is produced by the refinery and procured through the exchanges with third parties of gasoline, diesel and other refined products ("non-jet fuel products") the refinery produces. Cost is determined using the first-in, first-out method. Costs include the raw material consumed plus direct manufacturing costs (such as labor, utilities and supplies) as incurred and an applicable portion of manufacturing overhead.

Expendables Parts and Supplies. Inventories of expendable parts related to flight equipment, which cannot be economically repaired, reconditioned or reused after removal from the aircraft, are carried at moving average cost and charged to aircraft maintenance materials and outside repairs as consumed. An allowance for obsolescence is provided over the remaining useful life of the related fleet. We also provide allowances for parts identified as excess or obsolete to reduce the carrying costs to the lower of cost or net realizable value. These parts are estimated to have residual value of 5% of the original cost.
Accounting for Refinery Related Buy/Sell Agreements
Accounting for Refinery Related Buy/Sell Agreements

To the extent that we receive jet fuel for non-jet fuel products exchanged under buy/sell agreements, we account for these transactions as nonmonetary exchanges. We have recorded these nonmonetary exchanges at the carrying amount of the non-jet fuel products transferred within aircraft fuel and related taxes on the income statement.
Derivatives
Derivatives
Changes in fuel prices, interest rates and foreign currency exchange rates impact our results of operations. In an effort to manage our exposure to these risks, we may enter into derivative contracts and adjust our derivative portfolio as market conditions change.
Property and Equipment, net
Long-Lived Assets
Our long-lived lived assets include property and equipment, net and operating lease right-of-use ("ROU") assets on our balance sheets. We record property and equipment at cost and depreciate or amortize these assets on a straight-line basis to their estimated residual values over their estimated useful lives. The estimated useful life for leasehold improvements is the shorter of lease term or estimated useful life.We capitalize certain internal and external costs incurred to develop and implement software and amortize those costs over an estimated useful life of three to fifteen years.
Our tangible assets consist primarily of flight equipment, which is mobile across geographic markets. Accordingly, assets are not allocated to specific geographic regions.
Impairment of Long-Lived Assets
We review flight equipment, ROU assets and other long-lived assets used in operations for impairment losses when events and circumstances indicate the assets may be impaired. Factors which could be indicators of impairment include, but are not limited to (1) a decision to permanently remove flight equipment or other long-lived assets from operations, (2) significant changes in the estimated useful life, (3) significant changes in projected cash flows, (4) permanent and significant declines in fleet fair values and (5) changes to the regulatory environment. For long-lived assets held for sale, we discontinue depreciation and record impairment losses when the carrying amount of these assets is greater than the fair value less the cost to sell.

To determine whether impairments exist for aircraft used in operations, we group assets at the fleet type level or at the contract level for aircraft operated by third-party regional carriers (i.e., the lowest level for which there are identifiable cash flows) and then estimate future cash flows based on projections of capacity, passenger mile yield, fuel and labor costs and other relevant factors. If an asset group is impaired, the impairment loss recognized is the amount by which the asset group's carrying amount exceeds its estimated fair value. We estimate aircraft fair values using published sources, appraisals and bids received from third parties, as available.
Income Taxes
Income Taxes

We account for deferred income taxes under the liability method. We recognize deferred tax assets and liabilities based on the tax effects of temporary differences between the financial statement and tax basis of assets and liabilities, as measured by current enacted tax rates. Deferred tax assets and liabilities are net by jurisdiction and are recorded as noncurrent on the balance sheets.

We have elected to recognize global intangible low tax income in the period it arises and do not recognize deferred taxes for basis differences that may reverse in future years.
A valuation allowance is recorded to reduce deferred tax assets when necessary. We periodically assess whether it is more likely than not that we will generate sufficient taxable income to realize our deferred income tax assets. We establish valuation allowances if it is more likely than not that we will be unable to realize our deferred income tax assets. In making this determination, we consider available positive and negative evidence and make certain assumptions. We consider, among other things, projected future taxable income, scheduled reversals of deferred tax liabilities, the overall business environment, our historical financial results and tax planning strategies.
Fuel Card Obligation
Fuel Card Obligation
We have a purchasing card with American Express for the purpose of buying jet fuel and crude oil.
Manufacturers' Credits
Manufacturers' Credits

We periodically receive credits in connection with the acquisition of aircraft and engines. These credits are deferred until the aircraft and engines are delivered, and then applied as a reduction to the cost of the related equipment.
Maintenance Costs
Maintenance Costs

We record maintenance costs related to our mainline and regional fleets in aircraft maintenance materials and outside repairs and regional carrier expense, respectively. Maintenance costs are expensed as incurred, except for costs incurred under power-by-the-hour contracts, which are expensed based on actual hours flown. Power-by-the-hour contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per flight cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized and amortized over the remaining estimated useful life of the asset or the remaining lease term, whichever is shorter.
Advertising Costs
Advertising Costs
We expense advertising costs in passenger commissions and other selling expenses in the year the advertising first takes place.
Commissions and Merchant Fees
Commissions and Merchant Fees

Passenger sales commissions and merchant fees are recognized in passenger commissions and other selling expenses when the related revenue is recognized.
Goodwill and Indefinite-Lived Intangible Assets
Goodwill and Indefinite-Lived Intangible Assets

Our goodwill and identifiable intangible assets relate to the airline segment. We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. We assess the value of our goodwill and indefinite-lived assets under either a qualitative or quantitative approach. Under a qualitative approach, we consider various market factors, including certain of the key assumptions listed below. We analyze these factors to determine if events and circumstances have affected the fair value of goodwill and indefinite-lived intangible assets. If we determine that it is more likely than not that the asset may be impaired, we use the quantitative approach to assess the asset's fair value and the amount of the impairment. Under a quantitative approach, we calculate the fair value of the asset incorporating the key assumptions listed below into our calculation.
We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions (1) forecasted revenues, expenses and cash flows, (2) current discount rates, (3) observable market transactions and (4) anticipated changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals). These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. We recognize an impairment charge if the asset's carrying value exceeds its estimated fair value.

Changes in certain events and circumstances could result in impairment or a change from indefinite-lived to definite-lived. Factors which could cause impairment include, but are not limited to (1) negative trends in our market capitalization, (2) reduced profitability resulting from lower passenger mile yields or higher input costs (primarily related to fuel and employees), (3) lower passenger demand as a result of weakened U.S. and global economies or other factors, (4) interruption to our operations due to a prolonged employee strike, terrorist attack or other reasons, (5) changes to the regulatory environment (e.g., changes in slot access and/or availability, additional Open Skies agreements or changes to antitrust approvals), (6) competitive changes by other airlines and (7) strategic changes to our operations leading to diminished utilization of the intangible assets.

Identifiable Intangible Assets. Indefinite-lived assets are not amortized and consist of routes, slots, the Delta tradename and assets related to alliances and collaborative arrangements. Definite-lived intangible assets consist primarily of marketing and maintenance service agreements and are amortized on a straight-line basis or under the undiscounted cash flows method over the estimated economic life of the respective agreements. Costs incurred to renew or extend the term of an intangible asset are expensed as incurred.
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
Reconciliation of cash, cash equivalents, and restricted cash
The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets ("balance sheets") that sum to the total of the same such amounts shown within the Consolidated Statements of Cash Flows ("cash flows statement").

Reconciliation of cash, cash equivalents and restricted cash
December 31,
(in millions)202320222021
Current assets:
Cash and cash equivalents$2,741 $3,266 $7,933 
Restricted cash included in prepaid expenses and other199 138 163 
Noncurrent assets:
Restricted cash included in other noncurrent assets455 69 473 
Total cash, cash equivalents and restricted cash$3,395 $3,473 $8,569 
Summary of property and equipment by classification The following table summarizes our property and equipment:
Property and equipment by classification
December 31,
(in millions, except for estimated useful life)Estimated Useful Life20232022
Flight equipment(1)
25-34 years
$40,976 $38,091 
Ground property and equipment
3-40 years
9,986 8,996 
Information technology-related assets
3-15 years
3,307 3,375 
Flight and ground equipment under finance leasesShorter of lease term or estimated useful life1,862 1,950 
Advance payments for equipment1,062 1,067 
Less: accumulated depreciation and amortization(2)
(21,707)(20,370)
Total property and equipment, net$35,486 $33,109 
(1)Includes aircraft and associated engines and parts.
(2)Includes accumulated amortization for flight and ground equipment under finance leases in the amount of $525 million and $463 million at December 31, 2023 and 2022, respectively.
v3.24.0.1
REVENUE RECOGNITION (Tables)
 12 Months Ended
Dec. 31, 2023
Revenue from Contract with Customer [Abstract]  
Schedule of disaggregation of revenue
Passenger revenue is composed of passenger ticket sales, loyalty travel awards and travel-related services performed in conjunction with a passenger’s flight.

Passenger revenue by category
Year Ended December 31,
(in millions)202320222021
Ticket$43,596 $35,626 $19,339 
Loyalty travel awards3,462 2,898 1,786 
Travel-related services1,851 1,694 1,394 
Total passenger revenue$48,909 $40,218 $22,519 
Other Revenue
Year Ended December 31,
(in millions)202320222021
Refinery$3,379 $4,977 $3,229 
Loyalty program3,093 2,597 1,770 
Ancillary businesses840 846 793 
Miscellaneous1,104 894 556 
Total other revenue$8,416 $9,314 $6,348 
Schedule loyalty program activity
The table below presents the activity of the current and noncurrent loyalty program deferred revenue, and includes miles earned through travel and miles sold to participating companies, which are primarily through marketing agreements.

Loyalty program activity
(in millions)202320222021
Balance at January 1$7,882 $7,559 $7,182 
Miles earned4,173 3,419 2,238 
Travel miles redeemed(3,462)(2,898)(1,786)
Non-travel miles redeemed(173)(198)(75)
Balance at December 31$8,420 $7,882 $7,559 
Schedule of revenue by geographic region Our passenger and operating revenue by geographic region are summarized in the following table:
Revenue by geographic region
Passenger RevenueOperating Revenue
Year Ended December 31,Year Ended December 31,
(in millions)202320222021202320222021
Domestic$33,968 $30,197 $18,468 $40,845 $38,478 $24,320 
Atlantic9,057 6,093 1,777 10,458 7,429 2,537 
Latin America3,798 2,889 1,873 4,292 3,334 2,284 
Pacific2,086 1,039 401 2,453 1,341 758 
Total$48,909 $40,218 $22,519 $58,048 $50,582 $29,899 
v3.24.0.1
FAIR VALUE MEASUREMENTS (Tables)
 12 Months Ended
Dec. 31, 2023
Fair Value Disclosures [Abstract]  
Schedule of assets (liabilities) measured at fair value on a recurring basis
Assets (Liabilities) Measured at Fair Value on a Recurring Basis(1)
December 31, 2023Valuation Technique
(in millions)TotalLevel 1Level 2Level 3
Cash equivalents$1,545 $1,545 $— $— (a)
Restricted cash equivalents653 653 — — (a)
Short-term investments
U.S. Government securities859 204 655 — (a)
Corporate obligations218 — 218 — (a)
Other fixed income securities50 — 50 — (a)
Long-term investments and related2,867 2,614 134 119 (a)(b)
Hedge derivatives, net
Fuel hedge contracts5 — 5 — (a)(b)

December 31, 2022Valuation Technique
(in millions)TotalLevel 1Level 2Level 3
Cash equivalents$2,021 $2,021 $— $— (a)
Restricted cash equivalents206 206 — — (a)
Short-term investments
U.S. Government securities1,587 122 1,465 — (a)
Corporate obligations1,614 — 1,614 — (a)
Other fixed income securities67 — 67 — (a)
Long-term investments1,450 1,305 38 107 (a)(b)
Hedge derivatives, net
Fuel hedge contracts(47)— (47)— (a)(b)
(1)See Note 9, "Employee Benefit Plans," for fair value of benefit plan assets.
v3.24.0.1
INVESTMENTS (Tables)
 12 Months Ended
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]  
Schedule of fair value investments ownership interest and carrying value
Equity investments ownership interest and carrying value
Accounting TreatmentOwnership InterestCarrying Value
(in millions)December 31, 2023December 31, 2022December 31, 2023December 31, 2022
Air France-KLMFair Value3 %3 %$110 $97 
China EasternFair Value2 %2 %134 189 
CLEARFair Value6 %5 %171 227 
Grupo Aeroméxico
Equity Method(1)
20 %20 %421 412 
Hanjin-KAL
Fair Value(2)
15 %15 %561 296 
LATAMFair Value10 %10 %658 403 
Unifi Aviation
Equity Method(3)
49 %49 %162 165 
Wheels Up
Fair Value(4)
38 %21 %903 54 
Other investmentsVarious337 285 
Equity investments$3,457 $2,128 
(1)Results are included in miscellaneous, net in our income statement under non-operating expense.
(2)At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL.
(3)Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations.
(4)See below for additional information about our ownership interest and voting rights.
Schedule of equity method investments ownership interest and carrying value
Equity investments ownership interest and carrying value
Accounting TreatmentOwnership InterestCarrying Value
(in millions)December 31, 2023December 31, 2022December 31, 2023December 31, 2022
Air France-KLMFair Value3 %3 %$110 $97 
China EasternFair Value2 %2 %134 189 
CLEARFair Value6 %5 %171 227 
Grupo Aeroméxico
Equity Method(1)
20 %20 %421 412 
Hanjin-KAL
Fair Value(2)
15 %15 %561 296 
LATAMFair Value10 %10 %658 403 
Unifi Aviation
Equity Method(3)
49 %49 %162 165 
Wheels Up
Fair Value(4)
38 %21 %903 54 
Other investmentsVarious337 285 
Equity investments$3,457 $2,128 
(1)Results are included in miscellaneous, net in our income statement under non-operating expense.
(2)At December 31, 2023, we held 14.8% of the outstanding shares (including common and preferred), and 14.9% of the common shares, of Hanjin KAL.
(3)Results are included in contracted services in our income statement as this entity is integral to the operations of our business by providing services at many of our airport locations.
(4)See below for additional information about our ownership interest and voting rights.
v3.24.0.1
GOODWILL AND INTANGIBLE ASSETS (Tables)
 12 Months Ended
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule goodwill and indefinite-lived intangible assets by category
Goodwill and indefinite-lived intangible assets by category
Carrying Value atExcess Fair Value at 2023 Testing Date
(in millions)December 31, 2023December 31, 2022
Goodwill$9,753 $9,753 
>100%
International routes and slots2,583 2,583 
20% to >100%
Airline alliances1,863 1,863 
30% to >100%
Delta tradename850 850 
>100%
Domestic slots622 622 
60% to >100%
Total$15,671 $15,671 
Schedule of definite-lived intangible assets by category
Definite-Lived Intangible Assets

Definite-lived intangible assets by category
December 31, 2023December 31, 2022
(in millions)Gross Carrying Value 
Accumulated Amortization		Gross Carrying ValueAccumulated Amortization
Marketing agreements$730 $(708)$730 $(704)
Maintenance contracts192 (150)192 (145)
Other54 (53)54 (53)
Total$976 $(911)$976 $(902)
v3.24.0.1
DEBT (Tables)
 12 Months Ended
Dec. 31, 2023
Debt Disclosure [Abstract]  
Schedule of outstanding debt by category
The following table summarizes our debt as of the dates indicated below:

Summary of outstanding debt by category
Maturity Dates
Interest Rate(s) Per Annum at December 31, 2023
December 31,
(in millions)20232022
Unsecured Payroll Support Program Loans2030to 20311.00%$3,496 $3,496 
Unsecured notes2024to20292.90%to7.38%2,590 2,997 
Financing arrangements secured by SkyMiles assets:
SkyMiles Notes(1)
2024to20284.50%and 4.75%4,518 5,144 
SkyMiles Term Loan(1)(2)
2024to20279.17%1,772 2,820 
NYTDC Special Facilities Revenue Bonds(1)
2024to20454.00%to6.00%3,656 2,838 
Financing arrangements secured by aircraft:
Certificates(1)
2024to20282.00%to8.00%1,591 1,802 
Notes(1)(2)
2024to20336.72%to7.65%165 813 
Financing arrangements secured by slots, gates and/or routes:
2020 Senior Secured Notes20257.00%838 1,542 
2018 Revolving Credit Facility(2)
2026to2028Undrawn— — 
Other financings(1)(2)
2024to20302.51%to5.00%67 67 
Other revolving credit facilities(2)
2024to2026Undrawn— — 
Total secured and unsecured debt18,693 21,519 
Unamortized (discount)/premium and debt issuance cost, net and other(83)(138)
Total debt18,610 21,381 
Less: current maturities(2,625)(2,055)
Total long-term debt$15,985 $19,326 
(1)Due in installments.
(2)Certain financings are comprised of variable rate debt. All variable rates are equal to SOFR (generally subject to a floor) or another index rate plus a specified margin.
Schedule of fair value of outstanding debt The fair value of debt, shown below, is principally based on reported market values, recently completed market transactions and estimates based on interest rates, maturities, credit risk and underlying collateral. Debt is primarily classified as Level 2 within the fair value hierarchy.
Fair value of outstanding debt
(in millions)December 31,
2023		December 31,
2022
Net carrying amount$18,610 $21,381 
Fair value$18,400 $20,700 
Schedule of future debt maturities
The following table summarizes scheduled maturities of our debt for the years succeeding December 31, 2023:

Future debt maturities

(in millions)		Total DebtAmortization of
Debt (Discount)/Premium and Debt Issuance Cost, net and other
2024$2,633 $(49)
20252,006 (32)
20262,610 (6)
20272,315 — 
20281,884 — 
Thereafter7,245 4 
Total$18,693 $(83)$18,610 
v3.24.0.1
LEASES (Tables)
 12 Months Ended
Dec. 31, 2023
Leases [Abstract]  
Schedule of lease asset and liability balance sheet position by category
The table below presents the lease-related assets and liabilities recorded on the balance sheets.

Lease asset and liability balance sheet position by category
December 31,
(in millions)Classification on the Balance Sheet20232022
Assets
Operating lease assetsOperating lease right-of-use assets$7,004 $7,036 
Finance lease assetsProperty and equipment, net1,338 1,487 
Total lease assets$8,342 $8,523 
Liabilities
Current
OperatingCurrent maturities of operating leases$759 $714 
FinanceCurrent maturities of debt and finance leases358 304 
Noncurrent
OperatingNoncurrent operating leases6,468 6,866 
FinanceDebt and finance leases1,086 1,345 
Total lease liabilities$8,671 $9,229 
Weighted-average remaining lease term
Operating leases13 years13 years
Finance leases4 years5 years
Weighted-average discount rate
Operating leases
3.73 %4.30 %
Finance leases3.12 %3.05 %
Schedule of lease cost by category
The table below presents certain information related to the lease costs for finance and operating leases.

Lease cost by category
Year Ended December 31,
(in millions)202320222021
Finance lease cost
Amortization of leased assets$109 $120 $131 
Interest of lease liabilities42 45 55 
Operating lease cost(1)
981 949 863 
Short-term lease cost(1)
258 281 245 
Variable lease cost(1)
2,230 1,859 1,599 
Total lease cost$3,620 $3,254 $2,893 
(1)Expenses are primarily classified within aircraft rent, landing fees and other rents and regional carrier expense on our income statement.
Schedule supplemental lease-related cash flow information
The table below presents supplemental cash flow information related to leases.

Supplemental lease-related cash flow information
Year Ended December 31,
(in millions)202320222021
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows for operating leases$1,230 $809 $999 
Operating cash flows for finance leases71 49 46 
Financing cash flows for finance leases264 363 336 
Schedule of future cash flows and reconciliation to the balance sheet, operating leases
The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets.

Future lease cash flows and reconciliation to the balance sheet
(in millions)Operating LeasesFinance Leases
2024$1,021 $395 
2025990 257 
2026899 192 
2027860 391 
2028772 164 
Thereafter4,705 157 
Total minimum lease payments9,247 1,556 
Less: amount of lease payments representing interest(2,020)(112)
Present value of future minimum lease payments7,227 1,444 
Less: current obligations under leases(759)(358)
Long-term lease obligations$6,468 $1,086 
Schedule of future cash flows and reconciliation to the balance sheet, finance leases
The table below reconciles the undiscounted cash flows for each of the first five years and total of the remaining years to the finance lease liabilities and operating lease liabilities recorded on the balance sheets.

Future lease cash flows and reconciliation to the balance sheet
(in millions)Operating LeasesFinance Leases
2024$1,021 $395 
2025990 257 
2026899 192 
2027860 391 
2028772 164 
Thereafter4,705 157 
Total minimum lease payments9,247 1,556 
Less: amount of lease payments representing interest(2,020)(112)
Present value of future minimum lease payments7,227 1,444 
Less: current obligations under leases(759)(358)
Long-term lease obligations$6,468 $1,086 
v3.24.0.1
EMPLOYEE BENEFIT PLANS (Tables)
 12 Months Ended
Dec. 31, 2023
Retirement Benefits [Abstract]  
Schedule of benefit obligations, fair value of plan assets, and funded status
Benefit Obligations, Fair Value of Plan Assets and Funded Status
Pension BenefitsOther Postretirement and Postemployment Benefits
December 31,December 31,
(in millions)2023202220232022
Benefit obligation at beginning of period$15,811 $21,073 $3,664 $4,605 
Service cost95 — 71 70 
Interest cost855 611 200 128 
Actuarial loss/(gain)351 (4,599)24 (710)
Benefits paid, including lump sums and annuities(1,201)(1,274)(485)(447)
Plan amendments— — 11 — 
Participant contributions— — 18 18 
Benefit obligation at end of period(1)
$15,911 $15,811 $3,503 $3,664 
Fair value of plan assets at beginning of period$15,721 $19,502 $71 $357 
Actual gain/(loss) on plan assets1,142 (2,517)3 (73)
Employer contributions104 10 426 216 
Participant contributions— — 18 18 
Benefits paid, including lump sums and annuities(1,201)(1,274)(485)(447)
Fair value of plan assets at end of period$15,766 $15,721 $33 $71 
Funded status at end of period$(145)$(90)$(3,470)$(3,593)
(1) At the end of each year presented, our accumulated benefit obligations for our pension plans are equal to the benefit obligations shown above.
Schedule of amounts balance sheet position
Balance Sheet Position
Pension BenefitsOther Postretirement and Postemployment Benefits
December 31,December 31,
(in millions)2023202220232022
Prepaid pension assets$22 $27 $— $— 
Current liabilities(9)(9)(404)(369)
Noncurrent liabilities(158)(108)(3,066)(3,224)
Funded status at end of period$(145)$(90)$(3,470)$(3,593)
Net actuarial (loss)/gain$(6,474)$(6,444)$(162)$(155)
Prior service credit— — 1 18 
Total accumulated other comprehensive loss, pre-tax$(6,474)$(6,444)$(161)$(137)
Schedule of net periodic cost (benefit)
Net Periodic Cost/(Benefit)
Pension BenefitsOther Postretirement and Postemployment Benefits
Year Ended December 31,Year Ended December 31,
(in millions)202320222021202320222021
Service cost$95 $— $— $71 $70 $86 
Interest cost855 611 582 200 128 117 
Expected return on plan assets(1,060)(1,319)(1,522)(1)(17)(34)
Amortization of prior service credit— — — (5)(5)(6)
Recognized net actuarial loss240 255 354 14 56 55 
Settlements— — 2 — — — 
Net periodic cost/(benefit)
$130 $(453)$(584)$279 $232 $218 
Schedule of assumptions used to determine benefit obligations and net periodic costs/ (benefit)
We used the following actuarial assumptions to determine our benefit obligations and our net periodic cost/(benefit) for the periods presented:
December 31,
Benefit Obligations(1)
20232022
Weighted average discount rate5.31 %5.62 %

Year Ended December 31,
Net Periodic Cost/(Benefit)(1)
202320222021
Weighted average discount rate5.59 %2.96 %2.61 %
Weighted average expected long-term rate of return on plan assets7.00 %7.00 %8.98 %
Assumed healthcare cost trend rate for the next year(2)
6.25 %6.50 %6.25 %
(1)Future employee compensation levels do not impact our frozen defined benefit pension plans or other postretirement plans and impact only a small portion of our other postemployment obligation.
(2)Healthcare cost trend rate is assumed to decline gradually to 5.00% by 2029 and remain unchanged thereafter.
Schedule of expected future benefit payments
The following table summarizes the benefit payments that are expected to be paid in the years ending December 31:

Expected future benefit payments
(in millions)Pension BenefitsOther Postretirement and Postemployment Benefits
2024$1,310 $450 
20251,350 440 
20261,350 440 
20271,360 440 
20281,360 450 
2029-20336,670 2,190 
Schedule of benefit plan assets measured at fair value on recurring basis The following table shows our benefit plan assets by asset class.
Benefit plan assets measured at fair value on a recurring basis
December 31, 2023December 31, 2022Valuation Technique
(in millions)Level 1Level 2TotalLevel 1Level 2Total
Fixed income and fixed income-related instruments$300 $1,858 $2,158 $77 $1,366 $1,443 (a)(b)
Cash equivalents471 685 1,156 629 265 894 (a)
Equities and equity-related instruments647 122 769 420 25 445 (a)
Delta common stock419 — 419 343 — 343 (a)
Real assets11 236 247 17 170 187 (a)
Benefit plan assets$1,848 $2,901 $4,749 $1,486 $1,826 $3,312 
Investments measured at net asset value ("NAV")(1)
11,417 12,329 
Total benefit plan assets$16,166 $15,641 
(1) Investments that were measured at NAV per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy.
Schedule of benefit plan investments assets measured at NAV
The following table summarizes investments measured at fair value based on NAV per share as a practical expedient:

Benefit plan investment assets measured at NAV
December 31, 2023December 31, 2022
(in millions)Fair ValueRedemption FrequencyRedemption Notice PeriodFair ValueRedemption FrequencyRedemption Notice Period
Hedge funds and hedge fund-related strategies$6,175 (1)
7-180 Days
$6,730 (1)
2-180 Days
Commingled funds, private equity and private equity-related instruments (4)
2,379 (1) (2)
0-45 Days
2,266 (1) (2)
2-45 Days
Fixed income and fixed income-related instruments(4)
1,147 (1)
1-180 Days
1,003 (1)
1-180 Days
Real assets (4)
893 (2)N/A819 (2)N/A
Other823 (3)
2-10 Days
1,511 (3)
2-10 Days
Total investments measured at NAV$11,417 $12,329 
(1)Various. Includes funds with monthly or more frequent, quarterly and/or custom redemption frequencies as well as funds with a redemption window following the anniversary of the initial investment.
(2)Includes private funds that are closed-ended structures in which the plans' investments are generally not eligible for redemption.
(3)Includes funds with monthly or more frequent redemptions.
(4)Unfunded commitments were $1.3 billion for commingled funds, private equity and private equity-related instruments, $296 million for fixed income and fixed income-related instruments and $584 million for real assets at December 31, 2023.
v3.24.0.1
COMMITMENTS AND CONTINGENCIES (Tables)
 12 Months Ended
Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]  
Schedule of aircraft purchase commitments
Our future aircraft purchase commitments totaled approximately $17.5 billion at December 31, 2023:

Aircraft purchase commitments(1)
(in millions)Total
2024$3,530 
20254,230 
20263,490 
20273,870 
20281,650 
Thereafter760 
Total$17,530 
(1)The timing of these commitments is based on our contractual agreements with the aircraft manufacturers and remains uncertain due to supply chain, manufacturing and regulatory constraints.
Our future aircraft purchase commitments included the following aircraft at December 31, 2023:

Aircraft purchase commitments by fleet type
Fleet TypePurchase Commitments
A220-30077 
A321-200neo107 
A330-900neo12 
A350-90016 
B-737-10100 
Total312 
Schedule of contract carrier minimum obligations The obligations set forth in the table contemplate minimum levels of flying by the regional carriers under the respective agreements and also reflect assumptions regarding certain costs associated with the minimum levels of flying such as the cost of fuel, labor, maintenance, insurance, catering, property tax and landing fees. Accordingly, our actual payments under these agreements could differ materially from the minimum fixed obligations set forth in the table below.
Contract carrier minimum obligations
(in millions)Amount
2024$1,600 
20251,540 
20261,560 
20271,520 
20281,260 
Thereafter1,360 
Total$8,840 
Schedule of domestic airline employees represented by collective bargaining agreements by group
Domestic airline employees represented by collective bargaining agreements by group
Employee GroupApproximate Number of
Employees Represented		UnionDate on which Collective
Bargaining Agreement
Becomes Amendable
Delta Pilots16,960 ALPADecember 31, 2026
Delta Flight Superintendents (Dispatchers)
490 PAFCANovember 1, 2024
Endeavor Pilots1,530 ALPAJanuary 1, 2029
Endeavor Flight Attendants
1,600 AFAMarch 31, 2027
v3.24.0.1
INCOME TAXES (Tables)
 12 Months Ended
Dec. 31, 2023
Income Tax Disclosure [Abstract]  
Schedule of components of income tax benefit (provision)
Components of income tax provision
Year Ended December 31,
(in millions)202320222021
Current tax provision:
Federal$— $— $— 
State and local(8)(1)(1)
International(11)(4)(3)
Deferred tax (provision) benefit:
Federal(896)(525)(130)
State and local(84)(66)16 
Income tax provision$(999)$(596)$(118)
Schedule of effective income tax rate reconciliation
The following table presents the principal reasons for the difference between the effective tax rate and the U.S. federal statutory income tax rate:

Reconciliation of statutory federal income tax rate to the effective income tax rate
Year Ended December 31,
202320222021
U.S. federal statutory income tax rate21.0 %21.0 %21.0 %
State taxes, net of federal benefit2.0 3.0 (4.4)
Permanent differences0.7 1.0 4.9 
Valuation allowance(5.0)7.3 9.1 
Other(0.9)(1.1)(0.8)
Effective income tax rate17.8 %31.2 %29.8 %
Schedule of significant components of deferred income tax assets and liabilities
Significant components of deferred income tax assets and liabilities
December 31,
(in millions)20232022
Deferred tax assets:
Net operating loss carryforwards$1,217 $1,395 
Capital loss carryforward8 50 
Pension, postretirement and other benefits1,488 1,467 
Investments806 1,106 
Deferred revenue2,110 2,334 
Lease liabilities2,193 2,376 
Other709 682 
Valuation allowance(877)(1,176)
Total deferred tax assets$7,654 $8,234 
Deferred tax liabilities:
Depreciation$5,570 $5,110 
Operating lease assets1,533 1,624 
Intangible assets1,143 1,121 
Other73 78 
Total deferred tax liabilities$8,319 $7,933 
Balance Sheet Position:
Other noncurrent assets$243 $325 
Deferred income taxes, net(908)(24)
Net deferred tax (liabilities) assets
$(665)$301 
Schedule of valuation allowance on deferred income tax assets
The following table presents the balance of our valuation allowance on our deferred income tax assets and the associated activity:

Valuation allowance activity
(in millions)20232022
Balance at January 1$1,176 $833 
Tax provision(299)155 
Equity investment activity— 188 
Balance at December 31$877 $1,176 
v3.24.0.1
EQUITY AND EQUITY COMPENSATION (Tables)
 12 Months Ended
Dec. 31, 2023
Equity [Abstract]  
Schedule of warrants
Summary of payroll support program warrants
(in millions)Number of WarrantsExercise PriceExpiration Year
Payroll Support Program (PSP1)6.8$24.25 2025
Payroll Support Program Extension (PSP2)2.439.54 2026
Payroll Support Program 3 (PSP3)1.947.57 2026
Total11.1
Schedule of restricted stock activity Restricted stock activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows:
Restricted Stock Award Activity
202320222021
Restricted
Stock Awards		Weighted-Average
Grant Price		Restricted
Stock Awards		Weighted-Average
Grant Price		Restricted
Stock Awards		Weighted-Average
Grant Price
(in millions, except weighted avg grant price)
Outstanding at January 13.1 $43.43 2.9 $45.66 2.2 $54.06 
Granted2.7 39.63 1.9 42.45 2.3 39.93 
Vested(1.5)44.79 (1.6)46.31 (1.4)51.15 
Forfeited(0.1)40.94 (0.1)45.51 (0.2)44.01 
Outstanding at December 314.2 $40.51 3.1 $43.43 2.9 $45.66 
Schedule of stock option activity Stock option activity under the Plan for the years ended December 31, 2023, 2022 and 2021 is as follows:
Stock Option Activity
202320222021
Stock OptionsWeighted-Average
Exercise Price		Stock OptionsWeighted-Average
Exercise Price		Stock OptionsWeighted-Average
Exercise Price
(in millions, except weighted avg grant price)
Outstanding at January 16.2 $50.40 6.2 $50.41 5.4 $52.37 
Granted— — — — 1.0 39.78 
Exercised(1)
— 39.78 — — — — 
Forfeited(1)
— 51.91 — 52.87 (0.2)49.61 
Outstanding at December 316.2 $50.42 6.2 $50.40 6.2 $50.41 
(1)2023 exercise and forfeiture and 2022 forfeiture activity in the table above rounds to zero.
v3.24.0.1
ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)
 12 Months Ended
Dec. 31, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]  
Schedule of components of accumulated other comprehensive loss
Components of accumulated other comprehensive loss
(in millions)
Pension and Other Benefits Liabilities(2)
OtherTax EffectTotal
Balance at January 1, 2021$(10,843)$41 $1,764 $(9,038)
Changes in value2,077 — (484)1,593 
Reclassifications into earnings(1)
411 — (96)315 
Balance at December 31, 2021
(8,355)41 1,184 (7,130)
Changes in value1,419 — (330)1,089 
Reclassifications into earnings(1)
312 — (72)240 
Balance at December 31, 2022
(6,624)41 782 (5,801)
Changes in value(303)(1)71 (233)
Reclassifications into earnings(1)
246 — (57)189 
Balance at December 31, 2023
$(6,681)$40 $796 $(5,845)
(1)Amounts reclassified from AOCI for pension and other benefits liabilities are recorded in pension and related (expense)/benefit in non-operating expense in the income statement.
(2)Includes approximately $755 million of deferred income tax expense as a result of tax law changes and prior valuation allowance releases through continuing operations, that will not be recognized in net income until pension and other benefit obligations are fully extinguished.
v3.24.0.1
SEGMENTS (Tables)
 12 Months Ended
Dec. 31, 2023
Segment Reporting [Abstract]  
Schedule of financial information by segment
Segment results are prepared based on our internal accounting methods described below, with reconciliations to consolidated amounts in accordance with GAAP. Our segments are not designed to measure operating income or loss directly related to the products and services included in each segment on a stand-alone basis.

Financial information by segment
(in millions)AirlineRefineryIntersegment Sales/OtherConsolidated
Year Ended December 31, 2023
Operating revenue$54,669 $7,572 $(4,193)
(1)
$58,048 
Depreciation and amortization2,341 94 (94)
(2)
2,341 
Operating income(2)
5,136 385 5,521 
Interest expense, net834 17 (17)834 
Total assets, end of period71,529 2,174 (59)73,644 
Capital expenditures5,088 235 5,323 
Year Ended December 31, 2022
Operating revenue$45,605 $10,706 $(5,729)
(1)
$50,582 
Depreciation and amortization2,107 93 (93)
(2)
2,107 
Operating income(2)
2,884 777 3,661 
Interest expense, net1,029 12 (12)1,029 
Total assets, end of period69,355 3,039 (106)72,288 
Capital expenditures6,217 149 6,366 
Year Ended December 31, 2021
Operating revenue$26,670 $6,054 $(2,825)
(1)
$29,899 
Depreciation and amortization1,998 95 (95)
(2)
1,998 
Operating income/(loss)(2)
1,888 (2)1,886 
Interest expense, net1,279 7 (7)1,279 
Total assets, end of period70,417 2,099 (57)72,459 
Capital expenditures3,188 59 3,247 
(1)See table below for detail of the intersegment operating revenue amounts.
(2)Refinery segment operating results, including depreciation and amortization, are included within aircraft fuel and related taxes in our income statement.

Operating Revenue Intersegment Sales/Other
Year Ended December 31,
(in millions)202320222021
Sales to airline segment(1)
$(1,535)$(1,976)$(492)
Exchanged products(2)
(2,354)(3,475)(2,293)
Sales of refined products
(304)(278)(40)
Total Operating Revenue Intersegment Sales/Other$(4,193)$(5,729)$(2,825)
(1)Represents transfers, valued on a market price basis, from the refinery to the airline segment for use in airline operations. We determine market price for jet fuel from the refinery by reference to the market index for the primary delivery location, which is New York Harbor.
(2)Represents value of products delivered under our exchange agreements, as discussed above, determined on a market price basis.
v3.24.0.1
EARNINGS PER SHARE (Tables)
 12 Months Ended
Dec. 31, 2023
Earnings Per Share [Abstract]  
Schedule of computation of basic and diluted (loss)/earnings per share The following table shows our computation:
Basic and diluted earnings per share
Year Ended December 31,
(in millions, except per share data)202320222021
Net income$4,609 $1,318 $280 
Basic weighted average shares outstanding639 638 636 
Dilutive effect of share-based instruments4 3 5 
Diluted weighted average shares outstanding643 641 641 
Basic earnings per share$7.21 $2.07 $0.44 
Diluted earnings per share$7.17 $2.06 $0.44 
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash Equivalents, and Restricted Cash Reconciliation (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Current assets:        
Cash and cash equivalents $ 2,741 $ 3,266 $ 7,933  
Restricted cash included in prepaid expenses and other 199 138 163  
Noncurrent assets:        
Restricted cash included in other noncurrent assets 455 69 473  
Total cash, cash equivalents and restricted cash $ 3,395 $ 3,473 $ 8,569 $ 10,055
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Summary of Significant Accounting Policies [Line Items]      
Derivative contracts, net $ 5,000,000 $ 47,000,000  
Depreciation and amortization expense related to property and equipment 2,341,000,000 2,107,000,000 $ 1,998,000,000
Amortization of capitalized software 340,000,000 307,000,000 301,000,000
Net book value of capitalized software 932,000,000 891,000,000  
Fuel card obligation 1,100,000,000 1,100,000,000  
Advertising expense 347,000,000 302,000,000 $ 198,000,000
Fuel Card Obligation      
Summary of Significant Accounting Policies [Line Items]      
Purchasing card maximum limit 1,100,000,000    
Fuel card obligation $ 1,100,000,000 $ 1,100,000,000  
Minimum      
Summary of Significant Accounting Policies [Line Items]      
Estimated residual value (percent) 5.00%    
Maximum      
Summary of Significant Accounting Policies [Line Items]      
Estimated residual value (percent) 10.00%    
Software and software development costs | Minimum      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 3 years    
Software and software development costs | Maximum      
Summary of Significant Accounting Policies [Line Items]      
Estimated useful life 15 years    
v3.24.0.1
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Property and Equipment, net (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Property, Plant and Equipment [Line Items]    
Less: accumulated depreciation and amortization $ (21,707) $ (20,370)
Total property and equipment, net 35,486 33,109
Flight equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 40,976 38,091
Flight equipment | Minimum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 25 years  
Flight equipment | Maximum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 34 years  
Ground property and equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 9,986 8,996
Ground property and equipment | Minimum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 3 years  
Ground property and equipment | Maximum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 40 years  
Information technology-related assets    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 3,307 3,375
Information technology-related assets | Minimum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 3 years  
Information technology-related assets | Maximum    
Property, Plant and Equipment [Line Items]    
Estimated useful life 15 years  
Flight and ground equipment under finance leases    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 1,862 1,950
Less: accumulated depreciation and amortization (525) (463)
Advance payments for equipment    
Property, Plant and Equipment [Line Items]    
Property and equipment, gross $ 1,062 $ 1,067
v3.24.0.1
REVENUE RECOGNITION - Passenger Revenue (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Disaggregation of Revenue [Line Items]      
Operating revenue $ 58,048 $ 50,582 $ 29,899
Passenger      
Disaggregation of Revenue [Line Items]      
Operating revenue 48,909 40,218 22,519
Ticket      
Disaggregation of Revenue [Line Items]      
Operating revenue 43,596 35,626 19,339
Loyalty travel awards      
Disaggregation of Revenue [Line Items]      
Operating revenue 3,462 2,898 1,786
Travel-related services      
Disaggregation of Revenue [Line Items]      
Operating revenue $ 1,851 $ 1,694 $ 1,394
v3.24.0.1
REVENUE RECOGNITION - Narrative (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Revenue from Contract with Customer [Abstract]      
Revenue recognized that was previously recorded in air traffic liability $ 7,400 $ 4,200 $ 2,200
Disaggregation of Revenue [Line Items]      
Marketing contracts initial terms, minimum (in years) 1 year    
Marketing contracts initial terms, maximum (in years) 13 years    
Cash sales of miles from marketing agreements $ 6,900 5,700 $ 4,100
Majority of new miles, redemption period (in years) 2 years    
Air traffic      
Disaggregation of Revenue [Line Items]      
Deferred revenue (current and noncurrent)   8,300  
Loyalty program deferred revenue   $ 100  
v3.24.0.1
REVENUE RECOGNITION - Loyalty Program Liability (Details) - Loyalty program - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Loyalty Program      
Current and noncurrent deferred revenue, beginning $ 7,882 $ 7,559 $ 7,182
Miles earned 4,173 3,419 2,238
Travel miles redeemed (3,462) (2,898) (1,786)
Non-travel miles redeemed (173) (198) (75)
Current and noncurrent deferred revenue, ending $ 8,420 $ 7,882 $ 7,559
v3.24.0.1
REVENUE RECOGNITION - Other Revenue (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Disaggregation of Revenue [Line Items]      
Operating revenue $ 58,048 $ 50,582 $ 29,899
Other      
Disaggregation of Revenue [Line Items]      
Operating revenue 8,416 9,314 6,348
Refinery      
Disaggregation of Revenue [Line Items]      
Operating revenue 3,379 4,977 3,229
Loyalty program      
Disaggregation of Revenue [Line Items]      
Operating revenue 3,093 2,597 1,770
Ancillary businesses      
Disaggregation of Revenue [Line Items]      
Operating revenue 840 846 793
Miscellaneous      
Disaggregation of Revenue [Line Items]      
Operating revenue $ 1,104 $ 894 $ 556
v3.24.0.1
Revenue Recognition - Revenue by Geographic Region (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Disaggregation of Revenue [Line Items]      
Operating revenue $ 58,048 $ 50,582 $ 29,899
Domestic      
Disaggregation of Revenue [Line Items]      
Operating revenue 40,845 38,478 24,320
Atlantic      
Disaggregation of Revenue [Line Items]      
Operating revenue 10,458 7,429 2,537
Latin America      
Disaggregation of Revenue [Line Items]      
Operating revenue 4,292 3,334 2,284
Pacific      
Disaggregation of Revenue [Line Items]      
Operating revenue 2,453 1,341 758
Passenger      
Disaggregation of Revenue [Line Items]      
Operating revenue 48,909 40,218 22,519
Passenger | Domestic      
Disaggregation of Revenue [Line Items]      
Operating revenue 33,968 30,197 18,468
Passenger | Atlantic      
Disaggregation of Revenue [Line Items]      
Operating revenue 9,057 6,093 1,777
Passenger | Latin America      
Disaggregation of Revenue [Line Items]      
Operating revenue 3,798 2,889 1,873
Passenger | Pacific      
Disaggregation of Revenue [Line Items]      
Operating revenue $ 2,086 $ 1,039 $ 401
v3.24.0.1
FAIR VALUE MEASUREMENTS - Fair Value Measurements on a Recurring Basis (Details) - Recurring - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Cash equivalents $ 1,545 $ 2,021
Restricted cash equivalents 653 206
Long-term investments and related 2,867 1,450
U.S. Government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 859 1,587
Corporate obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 218 1,614
Other fixed income securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 50 67
Fuel hedge contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Hedge derivatives, net 5 (47)
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Cash equivalents 1,545 2,021
Restricted cash equivalents 653 206
Long-term investments and related 2,614 1,305
Level 1 | U.S. Government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 204 122
Level 1 | Corporate obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 0 0
Level 1 | Other fixed income securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 0 0
Level 1 | Fuel hedge contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Hedge derivatives, net 0 0
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Cash equivalents 0 0
Restricted cash equivalents 0 0
Long-term investments and related 134 38
Level 2 | U.S. Government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 655 1,465
Level 2 | Corporate obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 218 1,614
Level 2 | Other fixed income securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 50 67
Level 2 | Fuel hedge contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Hedge derivatives, net 5 (47)
Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Cash equivalents 0 0
Restricted cash equivalents 0 0
Long-term investments and related 119 107
Level 3 | U.S. Government securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 0 0
Level 3 | Corporate obligations    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 0 0
Level 3 | Other fixed income securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Short-term investments 0 0
Level 3 | Fuel hedge contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis    
Hedge derivatives, net $ 0 $ 0
v3.24.0.1
FAIR VALUE MEASUREMENTS- Narrative (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Short-term investments $ 1,127 $ 3,268  
Fuel hedge contracts      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
(Loss) gain recognized on derivatives 6 $ 394 $ 146
Fuel hedge contracts | Settlement Gains On Contracts      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Loss on derivative 58    
Fuel hedge contracts | Mark-to-Market      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Gain on derivative $ 52    
v3.24.0.1
INVESTMENTS - Equity Investments Ownership Interest and Carrying Value (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Equity Investments    
Equity investments $ 3,457 $ 2,128
Air France-KLM    
Equity Investments    
Ownership Interest 3.00% 3.00%
Carrying Value $ 110 $ 97
China Eastern    
Equity Investments    
Ownership Interest 2.00% 2.00%
Carrying Value $ 134 $ 189
CLEAR    
Equity Investments    
Ownership Interest 6.00% 5.00%
Carrying Value $ 171 $ 227
Hanjin-KAL    
Equity Investments    
Ownership Interest 15.00% 15.00%
Carrying Value $ 561 $ 296
Hanjin-KAL | Common and Preferred Shares    
Equity Investments    
Ownership Interest 14.80%  
Hanjin-KAL | Common Stock    
Equity Investments    
Ownership Interest 14.90%  
LATAM    
Equity Investments    
Ownership Interest 10.00% 10.00%
Carrying Value $ 658 $ 403
Wheels Up    
Equity Investments    
Ownership Interest 38.00% 21.00%
Carrying Value $ 903 $ 54
Other investments    
Equity Investments    
Carrying Value $ 337 $ 285
Grupo Aeroméxico    
Equity Investments    
Ownership Interest 20.00% 20.00%
Carrying Value $ 421 $ 412
Unifi Aviation    
Equity Investments    
Ownership Interest 49.00% 49.00%
Carrying Value $ 162 $ 165
v3.24.0.1
Investments - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Aug. 15, 2023
Schedule of Equity Method Investments [Line Items]        
Gain on investments, net $ 1,263,000,000 $ (783,000,000) $ 56,000,000  
Virgin Atlantic        
Schedule of Equity Method Investments [Line Items]        
Carrying value of equity investment $ 0      
Ownership Interest 49.00%      
Unrecognized equity method losses $ 400,000,000      
Wheels Up        
Schedule of Equity Method Investments [Line Items]        
Liquidity threshold $ 100,000,000      
Ownership Interest 38.00% 21.00%    
Voting rights, shares held threshold 29.90%      
Gain on investments, net $ 786,000,000      
Public float percentage 5.00%      
Wheels Up | Line of Credit | Delta        
Schedule of Equity Method Investments [Line Items]        
Purchasing card maximum limit $ 100,000,000     $ 100,000,000
Line of credit       $ 0
Wheels Up | Line of Credit | Secured Debt        
Schedule of Equity Method Investments [Line Items]        
Debt instrument amount 390,000,000      
Wheels Up | Line of Credit | Secured Debt | Delta        
Schedule of Equity Method Investments [Line Items]        
Debt instrument amount 150,000,000      
Wheels Up | Line of Credit | Secured Debt | Other Investors        
Schedule of Equity Method Investments [Line Items]        
Debt instrument amount $ 240,000,000      
Wheels Up        
Schedule of Equity Method Investments [Line Items]        
Equity issuable 95.00%      
v3.24.0.1
GOODWILL AND INTANGIBLE ASSETS - Valuation of Goodwill and Indefinite-Lived Intangible (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Goodwill and indefinite-lived intangible assets    
Goodwill $ 9,753 $ 9,753
Goodwill and indefinite-lived intangible assets $ 15,671 15,671
Minimum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, goodwill (greater than) 100.00%  
International routes and slots    
Goodwill and indefinite-lived intangible assets    
Indefinite-lived intangibles $ 2,583 2,583
International routes and slots | Minimum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets 20.00%  
International routes and slots | Maximum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets 100.00%  
Airline alliances    
Goodwill and indefinite-lived intangible assets    
Indefinite-lived intangibles $ 1,863 1,863
Airline alliances | Minimum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets 30.00%  
Airline alliances | Maximum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets (greater than) 100.00%  
Delta tradename    
Goodwill and indefinite-lived intangible assets    
Indefinite-lived intangibles $ 850 850
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets (greater than) 100.00%  
Domestic slots    
Goodwill and indefinite-lived intangible assets    
Indefinite-lived intangibles $ 622 $ 622
Domestic slots | Minimum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets 60.00%  
Domestic slots | Maximum    
Excess Fair Value at 2023 Testing Date    
Excess fair value, indefinite-lived intangible assets (greater than) 100.00%  
v3.24.0.1
GOODWILL AND INTANGIBLE ASSETS - Definite-Lived Intangible Assets (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Finite-Lived Intangible Assets    
Gross carrying value $ 976 $ 976
Accumulated amortization (911) (902)
Marketing agreements    
Finite-Lived Intangible Assets    
Gross carrying value 730 730
Accumulated amortization (708) (704)
Maintenance contracts    
Finite-Lived Intangible Assets    
Gross carrying value 192 192
Accumulated amortization (150) (145)
Other    
Finite-Lived Intangible Assets    
Gross carrying value 54 54
Accumulated amortization $ (53) $ (53)
v3.24.0.1
GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]      
Amortization expense $ 9 $ 9 $ 10
Estimated amortization expense in 2022 8    
Estimated amortization expense in 2023 8    
Estimated amortization expense in 2024 8    
Estimated amortization expense in 2025 8    
Estimated amortization expense in 2026 $ 8    
v3.24.0.1
DEBT - Summary of Debt (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Debt Instrument [Line Items]    
Debt, gross $ 18,693 $ 21,519
Unamortized (discount)/premium and debt issuance cost, net and other (83) (138)
Total debt 18,610 21,381
Less: current maturities (2,625) (2,055)
Total long-term debt $ 15,985 19,326
Unsecured Payroll Support Program Loans | Unsecured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2030  
Maturity dates range, end Dec. 31, 2031  
Interest rate per annum (percent) 1.00%  
Debt, gross $ 3,496 3,496
Unsecured notes | Unsecured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2029  
Debt, gross $ 2,590 2,997
Unsecured notes | Unsecured Debt | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 2.90%  
Unsecured notes | Unsecured Debt | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 7.38%  
SkyMiles Notes | Secured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2028  
Debt, gross $ 4,518 5,144
SkyMiles Notes | Secured Debt | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 4.50%  
SkyMiles Notes | Secured Debt | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 4.75%  
SkyMiles Term Loan | Secured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2027  
Interest rate per annum (percent) 9.17%  
Debt, gross $ 1,772 2,820
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2045  
Debt, gross $ 3,656 2,838
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 4.00%  
NYTDC Special Facilities Revenue Bonds, Series 2020 | Bonds | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 6.00%  
Financings secured by aircraft - Certificates | Secured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2028  
Debt, gross $ 1,591 1,802
Financings secured by aircraft - Certificates | Secured Debt | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 2.00%  
Financings secured by aircraft - Certificates | Secured Debt | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 8.00%  
Financings secured by aircraft - Notes | Secured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2033  
Debt, gross $ 165 813
Financings secured by aircraft - Notes | Secured Debt | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 6.72%  
Financings secured by aircraft - Notes | Secured Debt | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 7.65%  
2020 Senior Secured Notes | Secured Debt    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 7.00%  
Debt, gross $ 838 1,542
2018 Revolving Credit Facility | Secured Debt    
Debt Instrument [Line Items]    
Maturity date Dec. 31, 2025  
2018 Revolving Credit Facility | Revolving Credit Facility    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2026  
Maturity dates range, end Dec. 31, 2028  
Debt, gross $ 0 0
Other financings | Secured and unsecured Debt    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2030  
Debt, gross $ 67 67
Other financings | Secured and unsecured Debt | Minimum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 2.51%  
Other financings | Secured and unsecured Debt | Maximum    
Debt Instrument [Line Items]    
Interest rate per annum (percent) 5.00%  
Other revolving credit facilities | Revolving Credit Facility    
Debt Instrument [Line Items]    
Maturity dates range, start Dec. 31, 2024  
Maturity dates range, end Dec. 31, 2026  
Debt, gross $ 0 $ 0
v3.24.0.1
DEBT - Early Settlement of Outstanding Notes (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Debt Instrument [Line Items]      
Repayment of principal $ 585    
Loss on extinguishment of debt 63 $ 100 $ 319
Secured and unsecured Debt      
Debt Instrument [Line Items]      
Repurchase amount 1,400    
Loss on extinguishment of debt $ 63    
v3.24.0.1
DEBT - Availability Under Revolving Credit Facilities (Details)
$ in Millions
Dec. 31, 2023
USD ($)
Debt Instrument [Line Items]  
Outstanding letters of credit that do not affect availability of revolvers $ 450
Revolving Credit Facility  
Debt Instrument [Line Items]  
Proceeds from revolving credit facilities $ 2,900
v3.24.0.1
DEBT - NYTDC Special Facilities Revenue Bonds, Series 2023 (Details)
$ in Millions
Dec. 31, 2023
USD ($)
NYTDC Special Facilities Revenue Bonds, Series 2023 | Bonds  
Debt Instrument [Line Items]  
Debt instrument amount $ 878
v3.24.0.1
DEBT - 2018 Revolving Credit Facility (Details)
 3 Months Ended
Dec. 31, 2023
USD ($)
ratingAgency
Line of Credit Facility [Line Items]  
Accordion feature $ 3,650,000,000
Revolving Credit Facility | 3 Year Revolving Credit Facility  
Line of Credit Facility [Line Items]  
Purchasing card maximum limit 1,325,000,000
Borrowing capacity available for letters of credit $ 250,000,000
Debt instrument term 3 years
Number of rating agencies with stable rating | ratingAgency 2
Revolving Credit Facility | 5 Year Revolving Credit Facility  
Line of Credit Facility [Line Items]  
Purchasing card maximum limit $ 1,325,000,000
Borrowing capacity available for letters of credit $ 250,000,000
Debt instrument term 5 years
Letter of Credit  
Line of Credit Facility [Line Items]  
Purchasing card maximum limit $ 360,000,000
Debt instrument term 3 years
v3.24.0.1
DEBT - Fair Value of Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Debt Disclosure [Abstract]    
Net carrying amount $ 18,610 $ 21,381
Fair value $ 18,400 $ 20,700
v3.24.0.1
DEBT - Covenants (Details) - SkyMiles program
$ in Millions
Dec. 31, 2023
USD ($)
Debt Instrument [Line Items]  
Minimum liquidity covenant $ 2,000
Aggregate limit on sale of pre-paid miles covenant $ 550
v3.24.0.1
DEBT - Future Maturities (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Total Debt    
2024 $ 2,633  
2025 2,006  
2026 2,610  
2027 2,315  
2028 1,884  
Thereafter 7,245  
Total 18,693 $ 21,519
Amortization of Debt (Discount)/Premium and Debt Issuance Cost, net and other    
2024 (49)  
2025 (32)  
2026 (6)  
2027 0  
2028 0  
Thereafter 4  
Total (83) (138)
Total debt $ 18,610 $ 21,381
v3.24.0.1
LEASES - Narrative (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2023
USD ($)
lease
aircraft
airport
Lessee, Lease, Description [Line Items]  
Leases that have not yet commenced | $ $ 151
Minimum  
Lessee, Lease, Description [Line Items]  
Leases that have not yet commenced, term of contract 4 years
Maximum  
Lessee, Lease, Description [Line Items]  
Leases that have not yet commenced, term of contract 19 years
Aircraft  
Lessee, Lease, Description [Line Items]  
Number of leases 225
Number of finance leases 111
Number of operating leases 114
Lease component of purchase agreements, number of aircraft | aircraft 116
Aircraft | Minimum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 5 months
Remaining term of finance leases 5 months
Aircraft | Maximum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 12 years
Remaining term of finance leases 12 years
Airport Facilities  
Lessee, Lease, Description [Line Items]  
Number of airports with facility space under lease | airport 300
Airport Facilities | Minimum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 1 month
Airport Facilities | Maximum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 29 years
Other Ground Property and Equipment | Minimum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 1 month
Remaining term of finance leases 1 month
Other Ground Property and Equipment | Maximum  
Lessee, Lease, Description [Line Items]  
Remaining term of operating leases 6 years
Remaining term of finance leases 6 years
v3.24.0.1
LEASES - Lease Position (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Assets    
Operating lease assets $ 7,004 $ 7,036
Finance lease assets 1,338 1,487
Total lease assets $ 8,342 $ 8,523
Finance lease asset, balance sheet Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370 Property and equipment, net of accumulated depreciation and amortization of $21,707 and $20,370
Liabilities    
Current operating lease liabilities $ 759 $ 714
Current finance lease liabilities 358 304
Long-term lease obligations 6,468 6,866
Noncurrent finance lease liabilities 1,086 1,345
Total lease liabilities $ 8,671 $ 9,229
Finance lease liability, current, balance sheet Current maturities of debt and finance leases Current maturities of debt and finance leases
Finance lease liability, noncurrent, balance sheet Debt and finance leases Debt and finance leases
Operating leases, weighted-average remaining lease term 13 years 13 years
Finance leases, weighted-average remaining lease term 4 years 5 years
Operating leases, weighted-average discount rate 3.73% 4.30%
Finance leases, weighted-average discount rate 3.12% 3.05%
v3.24.0.1
LEASES - Lease Costs (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Leases [Abstract]      
Finance lease cost, amortization of leased assets $ 109 $ 120 $ 131
Finance lease cost, interest of lease liabilities 42 45 55
Operating lease cost 981 949 863
Short-term lease cost 258 281 245
Variable lease cost 2,230 1,859 1,599
Total lease cost $ 3,620 $ 3,254 $ 2,893
v3.24.0.1
LEASES - Other Information (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Leases [Abstract]      
Operating cash flows for operating leases $ 1,230 $ 809 $ 999
Operating cash flows for finance leases 71 49 46
Financing cash flows for finance leases $ 264 $ 363 $ 336
v3.24.0.1
LEASES - Undiscounted Cash Flows (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Operating Leases    
2024 $ 1,021  
2025 990  
2026 899  
2027 860  
2028 772  
Thereafter 4,705  
Total minimum lease payments 9,247  
Less: amount of lease payments representing interest (2,020)  
Present value of future minimum lease payments 7,227  
Less: current obligations under leases (759) $ (714)
Long-term lease obligations 6,468 6,866
Finance Leases    
2024 395  
2025 257  
2026 192  
2027 391  
2028 164  
Thereafter 157  
Total minimum lease payments 1,556  
Less: amount of lease payments representing interest (112)  
Present value of future minimum lease payments 1,444  
Less: current obligations under leases (358) (304)
Long-term lease obligations $ 1,086 $ 1,345
v3.24.0.1
AIRPORT REDEVELOPMENT (Details)
 12 Months Ended 84 Months Ended
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
gate
Dec. 31, 2023
USD ($)
Jun. 30, 2023
USD ($)
Dec. 31, 2020
concourse
gate
Dec. 31, 2018
USD ($)
Agreements and Obligations [Line Items]              
Operating lease assets $ 7,004,000,000 $ 7,036,000,000   $ 7,004,000,000      
Financial Guarantee | Revolving Credit Facility              
Agreements and Obligations [Line Items]              
Aggregate commitments guaranteed         $ 626,000,000    
JFK Terminal Redevelopment Project              
Agreements and Obligations [Line Items]              
Number of new gates | gate     10        
Total expected project costs   1,600,000,000          
LAX Redevelopment Project              
Agreements and Obligations [Line Items]              
Total expected project costs 2,400,000,000     2,400,000,000      
Expected net projects costs 600,000,000     600,000,000      
Project costs reflected as investing cash flows       350,000,000      
Project costs reflected as operating cash flows       200,000,000      
Operating lease assets 200,000,000     200,000,000      
LAX Redevelopment Project | City of Los Angeles              
Agreements and Obligations [Line Items]              
Total appropriation to date by city 1,800,000,000     1,800,000,000      
Maximum reimbursement by city 1,800,000,000     1,800,000,000      
LaGuardia Airport Redevelopment Project              
Agreements and Obligations [Line Items]              
Total expected project costs 4,300,000,000     4,300,000,000      
Expected net projects costs 3,800,000,000     3,800,000,000      
Number of new gates planned | gate           37  
Number of concourses for gates | concourse           4  
Port Authority contribution to redevelopment project             $ 500,000,000
Amount spent on project costs $ 500,000,000 $ 650,000,000 $ 950,000,000 $ 3,700,000,000      
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Defined Benefit Plan Disclosure      
Discount rate for 17-year amortization period of unfunded liability for frozen defined benefit plan (percent) 8.85%    
Estimated funding by employer in next fiscal year $ 0    
Defined contribution plan costs $ 1,200,000,000 $ 1,000,000,000 $ 875,000,000
Assumed healthcare plan pre age 65 years    
Assumed healthcare plan post age 65 years    
Projected benefit obligation $ 8,600,000,000    
Fair value of plan asset $ 8,400,000,000    
Weighted average expected long-term rate of return on plan assets 7.00% 7.00% 8.98%
Profit sharing $ 1,383,000,000 $ 563,000,000 $ 108,000,000
Growth-seeking assets | Minimum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 20.00%    
Growth-seeking assets | Maximum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 40.00%    
Income-generating assets | Minimum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 25.00%    
Income-generating assets | Maximum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 35.00%    
Risk-diversifying assets | Minimum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 35.00%    
Risk-diversifying assets | Maximum      
Defined Benefit Plan Disclosure      
Plan assets, target allocations (percent) 45.00%    
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Benefit Obligations, Fair Value of Plan Assets and Funded Status (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Pension Benefits      
Change in Benefit Obligation      
Benefit obligation at beginning of period $ 15,811 $ 21,073  
Service cost 95 0 $ 0
Interest cost 855 611 582
Actuarial loss/(gain) 351 (4,599)  
Benefits paid, including lump sums and annuities (1,201) (1,274)  
Plan amendments 0 0  
Participant contributions 0 0  
Benefit obligation at end of period 15,911 15,811 21,073
Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 15,721 19,502  
Actual gain/(loss) on plan assets 1,142 (2,517)  
Employer contributions 104 10  
Participant contributions 0 0  
Benefits paid, including lump sums and annuities (1,201) (1,274)  
Fair value of plan assets at end of period 15,766 15,721 19,502
Funded Status of Plan      
Funded status at end of period (145) (90)  
Other Postretirement and Postemployment Benefits      
Change in Benefit Obligation      
Benefit obligation at beginning of period 3,664 4,605  
Service cost 71 70 86
Interest cost 200 128 117
Actuarial loss/(gain) 24 (710)  
Benefits paid, including lump sums and annuities (485) (447)  
Plan amendments 11 0  
Participant contributions 18 18  
Benefit obligation at end of period 3,503 3,664 4,605
Change in Fair Value of Plan Assets      
Fair value of plan assets at beginning of period 71 357  
Actual gain/(loss) on plan assets 3 (73)  
Employer contributions 426 216  
Participant contributions 18 18  
Benefits paid, including lump sums and annuities (485) (447)  
Fair value of plan assets at end of period 33 71 $ 357
Funded Status of Plan      
Funded status at end of period $ (3,470) $ (3,593)  
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Balance Sheet Position (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position    
Noncurrent liabilities $ (3,601) $ (3,707)
Pension Benefits    
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position    
Prepaid pension assets 22 27
Current liabilities (9) (9)
Noncurrent liabilities (158) (108)
Funded status at end of period (145) (90)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax    
Net actuarial (loss)/gain (6,474) (6,444)
Prior service credit 0 0
Total accumulated other comprehensive loss, pre-tax (6,474) (6,444)
Other Postretirement and Postemployment Benefits    
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position    
Prepaid pension assets 0 0
Current liabilities (404) (369)
Noncurrent liabilities (3,066) (3,224)
Funded status at end of period (3,470) (3,593)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax    
Net actuarial (loss)/gain (162) (155)
Prior service credit 1 18
Total accumulated other comprehensive loss, pre-tax $ (161) $ (137)
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Net Periodic Cost/(Benefit) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Pension Benefits      
Defined Benefit Plan Disclosure      
Service cost $ 95 $ 0 $ 0
Interest cost 855 611 582
Expected return on plan assets (1,060) (1,319) (1,522)
Amortization of prior service credit 0 0 0
Recognized net actuarial loss 240 255 354
Settlements 0 0 2
Net periodic cost/(benefit) 130 (453) (584)
Other Postretirement and Postemployment Benefits      
Defined Benefit Plan Disclosure      
Service cost 71 70 86
Interest cost 200 128 117
Expected return on plan assets (1) (17) (34)
Amortization of prior service credit (5) (5) (6)
Recognized net actuarial loss 14 56 55
Settlements 0 0 0
Net periodic cost/(benefit) $ 279 $ 232 $ 218
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Assumptions Used to Determine Benefit Obligation and Net Periodic Cost/(Benefit) (Details)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Defined Benefit Plan Disclosure      
Weighted average discount rate 5.31% 5.62%  
Weighted average expected long-term rate of return on plan assets 7.00% 7.00% 8.98%
Assumed healthcare cost trend rate for the next year 6.25% 6.50% 6.25%
Ultimate healthcare cost trend rate 5.00%    
Pension Benefits      
Defined Benefit Plan Disclosure      
Weighted average discount rate 5.59% 2.96% 2.61%
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Expected Benefit Payments (Details)
$ in Millions
Dec. 31, 2023
USD ($)
Pension Benefits  
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity  
2024 $ 1,310
2025 1,350
2026 1,350
2027 1,360
2028 1,360
2029-2033 6,670
Other Postretirement and Postemployment Benefits  
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity  
2024 450
2025 440
2026 440
2027 440
2028 450
2029-2033 $ 2,190
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Benefit Plan Assets Measured at Fair Value on Recurring Basis (Details) - Recurring - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Benefit plan assets by asset class    
Benefit plan assets $ 16,166 $ 15,641
Level 1 and Level 2    
Benefit plan assets by asset class    
Benefit plan assets 4,749 3,312
Level 1 and Level 2 | Fixed income and fixed income-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 2,158 1,443
Level 1 and Level 2 | Cash equivalents    
Benefit plan assets by asset class    
Benefit plan assets 1,156 894
Level 1 and Level 2 | Equities and equity-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 769 445
Level 1 and Level 2 | Delta common stock    
Benefit plan assets by asset class    
Benefit plan assets 419 343
Level 1 and Level 2 | Real assets    
Benefit plan assets by asset class    
Benefit plan assets 247 187
Level 1    
Benefit plan assets by asset class    
Benefit plan assets 1,848 1,486
Level 1 | Fixed income and fixed income-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 300 77
Level 1 | Cash equivalents    
Benefit plan assets by asset class    
Benefit plan assets 471 629
Level 1 | Equities and equity-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 647 420
Level 1 | Delta common stock    
Benefit plan assets by asset class    
Benefit plan assets 419 343
Level 1 | Real assets    
Benefit plan assets by asset class    
Benefit plan assets 11 17
Level 2    
Benefit plan assets by asset class    
Benefit plan assets 2,901 1,826
Level 2 | Fixed income and fixed income-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 1,858 1,366
Level 2 | Cash equivalents    
Benefit plan assets by asset class    
Benefit plan assets 685 265
Level 2 | Equities and equity-related instruments    
Benefit plan assets by asset class    
Benefit plan assets 122 25
Level 2 | Delta common stock    
Benefit plan assets by asset class    
Benefit plan assets 0 0
Level 2 | Real assets    
Benefit plan assets by asset class    
Benefit plan assets 236 170
NAV    
Benefit plan assets by asset class    
Benefit plan assets $ 11,417 $ 12,329
v3.24.0.1
EMPLOYEE BENEFIT PLANS - Investments Measured at NAV (Details) - NAV - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Investments measured at NAV    
Fair value of investment measured at NAV $ 11,417 $ 12,329
Hedge funds and hedge fund-related strategies    
Investments measured at NAV    
Fair value of investment measured at NAV $ 6,175 $ 6,730
Hedge funds and hedge fund-related strategies | Minimum    
Investments measured at NAV    
Redemption notice period 7 days 2 days
Hedge funds and hedge fund-related strategies | Maximum    
Investments measured at NAV    
Redemption notice period 180 days 180 days
Commingled funds, private equity and private equity-related instruments    
Investments measured at NAV    
Fair value of investment measured at NAV $ 2,379 $ 2,266
Unfunded commitments $ 1,300  
Commingled funds, private equity and private equity-related instruments | Minimum    
Investments measured at NAV    
Redemption notice period 0 days 2 days
Commingled funds, private equity and private equity-related instruments | Maximum    
Investments measured at NAV    
Redemption notice period 45 days 45 days
Fixed income and fixed income-related instruments    
Investments measured at NAV    
Fair value of investment measured at NAV $ 1,147 $ 1,003
Unfunded commitments $ 296  
Fixed income and fixed income-related instruments | Minimum    
Investments measured at NAV    
Redemption notice period 1 day 1 day
Fixed income and fixed income-related instruments | Maximum    
Investments measured at NAV    
Redemption notice period 180 days 180 days
Real assets    
Investments measured at NAV    
Fair value of investment measured at NAV $ 893 $ 819
Unfunded commitments 584  
Other    
Investments measured at NAV    
Fair value of investment measured at NAV $ 823 $ 1,511
Other | Minimum    
Investments measured at NAV    
Redemption notice period 2 days 2 days
Other | Maximum    
Investments measured at NAV    
Redemption notice period 10 days 10 days
v3.24.0.1
COMMITMENTS AND CONTINGENCIES - Aircraft Purchase Commitments and Contract Carrier Minimum Obligations (Details)
$ in Millions
Dec. 31, 2023
USD ($)
Aircraft purchase commitments  
Future commitments:  
2024 $ 3,530
2025 4,230
2026 3,490
2027 3,870
2028 1,650
Thereafter 760
Total 17,530
Capacity purchase agreements  
Future commitments:  
2024 1,600
2025 1,540
2026 1,560
2027 1,520
2028 1,260
Thereafter 1,360
Total $ 8,840
v3.24.0.1
COMMITMENTS AND CONTINGENCIES - Aircraft Purchase Commitments by Fleet Type (Details) - Aircraft purchase commitments
Dec. 31, 2023
aircraft
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 312
A220-300  
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 77
A321-200neo  
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 107
A330-900neo  
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 12
A350-900  
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 16
B-737-10  
Future Purchase Commitments  
Aircraft purchase commitments, minimum quantity required 100
v3.24.0.1
COMMITMENTS AND CONTINGENCIES - Narrative (Details)
$ in Millions
 1 Months Ended 3 Months Ended
Jan. 31, 2024
aircraft
Jun. 30, 2023
aircraft
Dec. 31, 2023
USD ($)
Future aircraft purchase commitments      
Future Purchase Commitments      
Future aircraft purchase commitments | $     $ 17,530
A330-900      
Future Purchase Commitments      
Number of aircraft agreed to be acquired   1  
A220-300      
Future Purchase Commitments      
Number of aircraft purchase rights exercised   26  
A350-1000 | Subsequent event      
Future Purchase Commitments      
Number of aircraft agreed to be acquired 20    
A350-1000 Widebody | Subsequent event      
Future Purchase Commitments      
Number of optional additional aircrafts 20    
v3.24.0.1
COMMITMENTS AND CONTINGENCIES - Employees Under Collective Bargaining Agreements Narrative (Details)
$ in Millions
 3 Months Ended
Jan. 01, 2023
Mar. 31, 2023
USD ($)
Dec. 31, 2023
employee
Other Commitments [Line Items]      
Approximate number of employees | employee     103,000
Percentage of employees represented by unions under collective bargaining agreements     20.00%
Collective bargaining agreement term 4 years    
Employee pay rate increase 18.00%    
Pilot agreement expense | $   $ 735  
Adjustments to other benefit-related items | $   $ 130  
Monroe refinery employees represented by United Steel Workers      
Other Commitments [Line Items]      
Approximate number of employees | employee     200
v3.24.0.1
COMMITMENTS AND CONTINGENCIES - Employees Under Collective Bargaining Agreements (Details)
Dec. 31, 2023
employee
Other Commitments [Line Items]  
Approximate Number of Employees Represented 103,000
Delta Pilots  
Other Commitments [Line Items]  
Approximate Number of Employees Represented 16,960
Delta Flight Superintendents (Dispatchers)  
Other Commitments [Line Items]  
Approximate Number of Employees Represented 490
Endeavor Pilots  
Other Commitments [Line Items]  
Approximate Number of Employees Represented 1,530
Endeavor Flight Attendants  
Other Commitments [Line Items]  
Approximate Number of Employees Represented 1,600
v3.24.0.1
INCOME TAXES - Components of Income Tax Benefit (Provision) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Current tax provision:      
Federal $ 0 $ 0 $ 0
State and local (8) (1) (1)
International (11) (4) (3)
Deferred tax (provision) benefit:      
Federal (896) (525) (130)
State and local (84) (66) 16
Income tax provision $ (999) $ (596) $ (118)
v3.24.0.1
INCOME TAXES - Effective Income Tax Rate Reconciliation (Details)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent      
U.S. federal statutory income tax rate 21.00% 21.00% 21.00%
State taxes, net of federal benefit 2.00% 3.00% (4.40%)
Permanent differences 0.70% 1.00% 4.90%
Valuation allowance (5.00%) 7.30% 9.10%
Other (0.90%) (1.10%) (0.80%)
Effective income tax rate 17.80% 31.20% 29.80%
v3.24.0.1
INCOME TAXES - Deferred Taxes (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Deferred tax assets:      
Net operating loss carryforwards $ 1,217 $ 1,395  
Capital loss carryforward 8 50  
Pension, postretirement and other benefits 1,488 1,467  
Investments 806 1,106  
Deferred revenue 2,110 2,334  
Lease liabilities 2,193 2,376  
Other 709 682  
Valuation allowance (877) (1,176) $ (833)
Total deferred tax assets 7,654 8,234  
Deferred tax liabilities:      
Depreciation 5,570 5,110  
Operating lease assets 1,533 1,624  
Intangible assets 1,143 1,121  
Other 73 78  
Total deferred tax liabilities 8,319 7,933  
Deferred income taxes, net 243 325  
Deferred income taxes, net (908) (24)  
Net deferred tax (liabilities) assets $ (665)    
Net deferred tax (liabilities) assets   $ 301  
v3.24.0.1
INCOME TAXES - Narrative (Details) - USD ($)
$ in Millions
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Income Tax Disclosure [Abstract]      
Deferred tax liabilities $ 665    
Valuation allowance 877 $ 1,176 $ 833
U.S. federal      
Income Taxes      
Operating loss carryforwards 4,500    
Operating loss carryforwards beginning to expire in 2029 $ 800    
v3.24.0.1
INCOME TAXES - Valuation Allowance (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Valuation allowance activity    
Valuation allowance, beginning $ 1,176 $ 833
Tax provision (299) 155
Equity investment activity 0 188
Valuation allowance, ending $ 877 $ 1,176
v3.24.0.1
EQUITY AND EQUITY COMPENSATION - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Class of Stock [Line Items]        
Capital stock, shares authorized (shares) 2,000,000,000      
Common stock, authorized (shares) 1,500,000,000 1,500,000,000    
Common stock, par value (USD per share) $ 0.0001 $ 0.0001    
Preferred stock, shares authorized (shares) 500,000,000      
Treasury stock weighted average cost per share (USD per share) $ 30.37 $ 29.73    
Grant payments received through payroll support program $ 4,500      
Number of shares authorized for issuance under the Plan (shares) 163,000,000      
Shares available for future grant (in shares) 13,000,000      
Equity compensation expense $ 180 $ 150 $ 149  
Compensation cost not yet recognized $ 103      
Outstanding stock option awards (shares) 6,200,000 6,200,000 6,200,000 5,400,000
Weighted average exercise price of options outstanding (USD per share) $ 50.42 $ 50.40 $ 50.41 $ 52.37
Number of exercisable stock option awards (shares) 5,900,000      
Restricted stock awards        
Class of Stock [Line Items]        
Unvested restricted stock awards (shares) 4,200,000 3,100,000 2,900,000 2,200,000
Stock options        
Class of Stock [Line Items]        
Term of award (in years) 10 years      
Performance awards        
Class of Stock [Line Items]        
Shares available for future grant (in shares)   700,000 1,500,000  
Performance period (in years) 3 years      
Performance awards | Minimum        
Class of Stock [Line Items]        
Potential performance award payments as percentage of target level 0.00%      
Performance awards | Maximum        
Class of Stock [Line Items]        
Potential performance award payments as percentage of target level 200.00%      
Performance-Based Restricted Stock Units        
Class of Stock [Line Items]        
Shares available for future grant (in shares) 3,300,000 1,300,000    
Performance period (in years) 3 years      
Performance-Based Restricted Stock Units | Minimum        
Class of Stock [Line Items]        
Potential performance award payments as percentage of target level 0.00%      
Performance-Based Restricted Stock Units | Maximum        
Class of Stock [Line Items]        
Potential performance award payments as percentage of target level 300.00%      
PSP Warrants | Payroll Support Program        
Class of Stock [Line Items]        
Number shares called by warrants (in shares)     11,100,000 11,100,000
v3.24.0.1
EQUITY AND EQUITY COMPENSATION - Warrants (Details)
shares in Millions
Dec. 31, 2023
$ / shares
shares
Class of Warrant or Right [Line Items]  
Number of Warrants (in shares) 11.1
Payroll Support Program (PSP1)  
Class of Warrant or Right [Line Items]  
Number of Warrants (in shares) 6.8
Exercise Price (usd per share) | $ / shares $ 24.25
Payroll Support Program Extension (PSP2)  
Class of Warrant or Right [Line Items]  
Number of Warrants (in shares) 2.4
Exercise Price (usd per share) | $ / shares $ 39.54
Payroll Support Program 3 (PSP3)  
Class of Warrant or Right [Line Items]  
Number of Warrants (in shares) 1.9
Exercise Price (usd per share) | $ / shares $ 47.57
v3.24.0.1
EQUITY AND EQUITY COMPENSATION - Restricted Stock Award Activity (Details) - Restricted Stock - $ / shares
shares in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Restricted Stock      
Outstanding, beginning (in shares) 3.1 2.9 2.2
Granted (in shares) 2.7 1.9 2.3
Vested (in shares) (1.5) (1.6) (1.4)
Forfeited (in shares) (0.1) (0.1) (0.2)
Outstanding, ending (in shares) 4.2 3.1 2.9
Restricted Stock, Weighted-Average Grant Price      
Outstanding, beginning (USD per share) $ 43.43 $ 45.66 $ 54.06
Granted (USD per share) 39.63 42.45 39.93
Vested (USD per share) 44.79 46.31 51.15
Forfeited (USD per share) 40.94 45.51 44.01
Outstanding, ending (USD per share) $ 40.51 $ 43.43 $ 45.66
v3.24.0.1
EQUITY AND EQUITY COMPENSATION - Stock Option Activity (Details) - $ / shares
shares in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Stock Options      
Outstanding, beginning (in shares) 6.2 6.2 5.4
Granted (in shares) 0.0 0.0 1.0
Exercised (in shares) 0.0 0.0 0.0
Forfeited (in shares) 0.0 0.0 (0.2)
Outstanding, ending (in shares) 6.2 6.2 6.2
Stock Options, Weighted-Average Grant Price      
Outstanding, beginning (USD per share) $ 50.40 $ 50.41 $ 52.37
Granted (USD per share) 0 0 39.78
Exercised (USD per share) 39.78 0 0
Forfeited (USD per share) 51.91 52.87 49.61
Outstanding, ending (USD per share) $ 50.42 $ 50.40 $ 50.41
v3.24.0.1
ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
AOCI Attributable to Parent, Net of Tax      
Beginning balance, tax effect $ 782 $ 1,184 $ 1,764
Beginning balance 6,582 3,887 1,534
Changes in value, tax effect 71 (330) (484)
Changes in value (net of tax effect) (233) 1,089 1,593
Reclassifications into earnings, tax effect (57) (72) (96)
Reclassification into earnings (net of tax effect) 189 240 315
Ending balance, tax effect 796 782 1,184
Ending balance 11,105 6,582 3,887
Deferred income tax expense in AOCI that will not be recognized until obligation is fully extinguished 755 755 755
Accumulated Other Comprehensive Loss      
AOCI Attributable to Parent, Net of Tax      
Beginning balance (5,801) (7,130) (9,038)
Ending balance (5,845) (5,801) (7,130)
Pension and Other Benefits Liabilities      
AOCI Attributable to Parent, Net of Tax      
Beginning balance, AOCI before tax (6,624) (8,355) (10,843)
Changes in value (303) 1,419 2,077
Reclassifications into earnings 246 312 411
Ending balance, AOCI before tax (6,681) (6,624) (8,355)
Other      
AOCI Attributable to Parent, Net of Tax      
Beginning balance, AOCI before tax 41 41 41
Changes in value (1) 0 0
Reclassifications into earnings 0 0 0
Ending balance, AOCI before tax $ 40 $ 41 $ 41
v3.24.0.1
SEGMENTS - Narrative (Details)
$ in Millions
 12 Months Ended
Dec. 31, 2023
USD ($)
segment
fleet
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Business Acquisition [Line Items]      
Number of operating segments | segment 2    
Number of fleets | fleet 1    
Operating revenue $ 58,048 $ 50,582 $ 29,899
Renewable energy asset retired 700    
Intersegment Sales/Other      
Business Acquisition [Line Items]      
Operating revenue (4,193) (5,729) (2,825)
Intersegment Sales/Other | Exchanged products      
Business Acquisition [Line Items]      
Operating revenue $ (2,354) $ (3,475) $ (2,293)
v3.24.0.1
SEGMENTS - Segment Reporting (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Segment Reporting Information, Profit (Loss)      
Operating revenue $ 58,048 $ 50,582 $ 29,899
Depreciation and amortization 2,341 2,107 1,998
Operating income (loss) 5,521 3,661 1,886
Interest expense, net 834 1,029 1,279
Total assets, end of period 73,644 72,288 72,459
Capital expenditures 5,323 6,366 3,247
Operating Segments | Airline      
Segment Reporting Information, Profit (Loss)      
Operating revenue 54,669 45,605 26,670
Depreciation and amortization 2,341 2,107 1,998
Operating income (loss) 5,136 2,884 1,888
Interest expense, net 834 1,029 1,279
Total assets, end of period 71,529 69,355 70,417
Capital expenditures 5,088 6,217 3,188
Operating Segments | Refinery      
Segment Reporting Information, Profit (Loss)      
Operating revenue 7,572 10,706 6,054
Depreciation and amortization 94 93 95
Operating income (loss) 385 777 (2)
Interest expense, net 17 12 7
Total assets, end of period 2,174 3,039 2,099
Capital expenditures 235 149 59
Intersegment Sales/Other      
Segment Reporting Information, Profit (Loss)      
Operating revenue (4,193) (5,729) (2,825)
Depreciation and amortization (94) (93) (95)
Interest expense, net (17) (12) (7)
Total assets, end of period (59) (106) (57)
Intersegment Sales/Other | Sales to airline segment      
Segment Reporting Information, Profit (Loss)      
Operating revenue (1,535) (1,976) (492)
Intersegment Sales/Other | Exchanged products      
Segment Reporting Information, Profit (Loss)      
Operating revenue (2,354) (3,475) (2,293)
Intersegment Sales/Other | Sales of refined products      
Segment Reporting Information, Profit (Loss)      
Operating revenue $ (304) $ (278) $ (40)
v3.24.0.1
EARNINGS PER SHARE (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Earnings Per Share [Abstract]      
Net income $ 4,609 $ 1,318 $ 280
Basic weighted average shares outstanding (shares) 639 638 636
Dilutive effect of share-based awards (shares) 4 3 5
Diluted weighted average shares outstanding (shares) 643 641 641
Basic earnings per share (USD per share) $ 7.21 $ 2.07 $ 0.44
Diluted earnings per share (USD per share) $ 7.17 $ 2.06 $ 0.44