Cover - USD ($) $ in Billions	12 Months Ended
Cover - USD ($) $ in Billions	Dec. 31, 2021	Feb. 18, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	000-19731
Entity Registrant Name	GILEAD SCIENCES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3047598
Entity Address, Address Line One	333 Lakeside Drive
Entity Address, City or Town	Foster City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94404
City Area Code	650
Local Phone Number	574-3000
Title of 12(b) Security	Common Stock, par value, $0.001 per share
Trading Symbol	GILD
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Public Float			$ 62.6
Entity Common Stock, Shares Outstanding		1,253,886,724
Documents Incorporated by Reference	Specified portions of the registrant’s proxy statement, which will be filed with the Commission pursuant to Regulation 14A in connection with the registrant’s 2022 Annual Meeting of Stockholders, to be held on May 4, 2022, are incorporated by reference into Part III of this Report.
Entity Central Index Key	0000882095
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	San Jose, California
Auditor Firm ID	42

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 5,338	$ 5,997
Short-term marketable debt securities	1,182	1,411
Accounts receivable, net	4,493	4,892
Inventories	1,618	1,683
Prepaid and other current assets	2,141	2,013
Total current assets	14,772	15,996
Property, plant and equipment, net	5,121	4,967
Long-term marketable debt securities	1,309	502
Intangible assets, net	33,455	33,126
Goodwill	8,332	8,108
Other long-term assets	4,963	5,708
Total assets	67,952	68,407
Current liabilities:
Accounts payable	705	844
Accrued government and other rebates	3,244	3,460
Accrued and other current liabilities	6,145	4,336
Current portion of long-term debt and other obligations, net	1,516	2,757
Total current liabilities	11,610	11,397
Long-term debt, net	25,179	28,645
Long-term income taxes payable	4,767	5,016
Deferred tax liability	4,356	3,914
Other long-term obligations	976	1,214
Commitments and contingencies (Note 14)
Stockholders’ equity:
Preferred stock, par value $0.001 per share; 5 shares authorized; none outstanding	0	0
Common stock, par value $0.001 per share; 5,600 authorized; 1,254 shares issued and outstanding as of December 31, 2021 and 2020	1	1
Additional paid-in capital	4,661	3,880
Accumulated other comprehensive income (loss)	83	(60)
Retained earnings	16,324	14,381
Total Gilead stockholders’ equity	21,069	18,202
Noncontrolling interest	(5)	19
Total stockholders’ equity	21,064	18,221
Total liabilities and stockholders’ equity	$ 67,952	$ 68,407

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Stockholders’ equity:
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	5,600,000,000	5,600,000,000
Common stock, issued (in shares)	1,254,000,000	1,254,000,000
Common stock, outstanding (in shares)	1,254,000,000	1,254,000,000

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Total revenues	$ 27,305	$ 24,689	$ 22,449
Costs and expenses:
Cost of goods sold	6,601	4,572	4,675
Research and development expenses	5,363	5,039	4,055
Acquired in-process research and development expenses	177	5,856	5,051
Selling, general and administrative expenses	5,246	5,151	4,381
Total costs and expenses	17,387	20,618	18,162
Income from operations	9,918	4,071	4,287
Interest expense	(1,001)	(984)	(995)
Other income (expense), net	(639)	(1,418)	1,868
Income before income taxes	8,278	1,669	5,160
Income tax (expense) benefit	(2,077)	(1,580)	204
Net income	6,201	89	5,364
Net loss attributable to noncontrolling interest	24	34	22
Net income attributable to Gilead	$ 6,225	$ 123	$ 5,386
Net income per share attributable to Gilead common stockholders - basic (in dollars per share)	$ 4.96	$ 0.10	$ 4.24
Shares used in per share calculation - basic (in shares)	1,256	1,257	1,270
Net income per share attributable to Gilead common stockholders - diluted (in dollars per share)	$ 4.93	$ 0.10	$ 4.22
Shares used in per share calculation - diluted (in shares)	1,262	1,263	1,277
Product sales
Revenues:
Total revenues	$ 27,008	$ 24,355	$ 22,119
Royalty, contract and other revenues
Revenues:
Total revenues	$ 297	$ 334	$ 330

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 6,201	$ 89	$ 5,364
Other comprehensive income (loss):
Net foreign currency translation gain (loss), net of tax	(38)	(2)	6
Available-for-sale debt securities:
Net unrealized gain (loss), net of tax	(6)	43	54
Reclassifications to net income, net of tax	0	(42)	(1)
Net change	(6)	1	53
Cash flow hedges:
Net unrealized gain (loss), net of tax	129	(103)	72
Reclassifications to net income, net of tax	58	(41)	(126)
Net change	187	(144)	(54)
Other comprehensive income (loss)	143	(145)	5
Comprehensive income (loss)	6,344	(56)	5,369
Comprehensive loss attributable to noncontrolling interest	24	34	22
Comprehensive income (loss) attributable to Gilead	$ 6,368	$ (22)	$ 5,391

Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Cumulative effect from the adoption of new accounting standard	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained Earnings Cumulative effect from the adoption of new accounting standard	Noncontrolling Interest
Beginning period (in shares) at Dec. 31, 2018			1,282
Beginning balance at Dec. 31, 2018	$ 21,534	$ 8	$ 1	$ 2,282	$ 80	$ 19,024	$ 8	$ 147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	5,364					5,386		(22)
Other comprehensive income (loss), net of tax	5				5
Issuances under employee stock purchase plan (in shares)			2
Issuances under employee stock purchase plan	90			90
Issuance under equity incentive plans (in shares)			10
Issuances under equity incentive plans	118			118
Stock-based compensation	638			638
Repurchases of common stock (in shares)			(28)
Repurchases of common stock	(1,868)			(77)		(1,791)
Dividends declared	(3,239)					(3,239)
Ending period (in shares) at Dec. 31, 2019			1,266
Ending balance at Dec. 31, 2019	22,650	$ (7)	$ 1	3,051	85	19,388	$ (7)	125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Change in noncontrolling interest	(72)							(72)
Net income (loss)	89					123		(34)
Other comprehensive income (loss), net of tax	(145)			1	(145)	(1)
Issuances under employee stock purchase plan (in shares)			2
Issuances under employee stock purchase plan	100			100
Issuance under equity incentive plans (in shares)			11
Issuances under equity incentive plans	156			156
Stock-based compensation	642			642
Repurchases of common stock (in shares)			(25)
Repurchases of common stock	(1,728)			(70)		(1,658)
Dividends declared	$ (3,464)					(3,464)
Ending period (in shares) at Dec. 31, 2020	1,254		1,254
Ending balance at Dec. 31, 2020	$ 18,221		$ 1	3,880	(60)	14,381		19
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	6,201					6,225		(24)
Other comprehensive income (loss), net of tax	143			0	143	0
Issuances under employee stock purchase plan (in shares)			2
Issuances under employee stock purchase plan	111			111
Issuance under equity incentive plans (in shares)			9
Issuances under equity incentive plans	58			58
Stock-based compensation	640			640
Repurchases of common stock (in shares)			(11)
Repurchases of common stock	(692)			(28)		(664)
Dividends declared	$ (3,618)					(3,618)
Ending period (in shares) at Dec. 31, 2021	1,254		1,254
Ending balance at Dec. 31, 2021	$ 21,064		$ 1	$ 4,661	$ 83	$ 16,324		$ (5)

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.71	$ 0.71	$ 0.71	$ 0.71	$ 0.68	$ 0.68	$ 0.68	$ 0.68	$ 2.84	$ 2.72	$ 2.52

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net income	$ 6,201,000,000	$ 89,000,000	$ 5,364,000,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense	329,000,000	288,000,000	255,000,000
Amortization expense	1,721,000,000	1,192,000,000	1,149,000,000
Stock-based compensation expense	635,000,000	643,000,000	636,000,000
Deferred income taxes	(116,000,000)	(214,000,000)	(2,098,000,000)
Net (gain) loss from equity securities	610,000,000	1,662,000,000	(1,241,000,000)
Acquired in-process research and development expenses	177,000,000	5,856,000,000	4,251,000,000
In-process research and development impairment	0	0	800,000,000
Write-downs for slow-moving and excess raw material and work in process inventory	121,000,000	40,000,000	547,000,000
Other	1,217,000,000	250,000,000	279,000,000
Changes in operating assets and liabilities:
Accounts receivable, net	313,000,000	(1,171,000,000)	(218,000,000)
Inventories	11,000,000	(195,000,000)	(95,000,000)
Prepaid expenses and other	(42,000,000)	(214,000,000)	(307,000,000)
Accounts payable	(118,000,000)	80,000,000	(61,000,000)
Income taxes payable	(364,000,000)	(778,000,000)	272,000,000
Accrued liabilities	689,000,000	640,000,000	(389,000,000)
Net cash provided by operating activities	11,384,000,000	8,168,000,000	9,144,000,000
Investing Activities:
Purchases of marketable debt securities	(3,517,000,000)	(20,315,000,000)	(30,455,000,000)
Proceeds from sales of marketable debt securities	730,000,000	23,239,000,000	7,523,000,000
Proceeds from maturities of marketable debt securities	2,180,000,000	9,479,000,000	22,398,000,000
Acquisitions, including in-process research and development, net of cash acquired	(1,402,000,000)	(25,742,000,000)	(4,251,000,000)
Purchases of equity securities	(380,000,000)	(455,000,000)	(1,773,000,000)
Capital expenditures	(579,000,000)	(650,000,000)	(825,000,000)
Other	(163,000,000)	(171,000,000)	(434,000,000)
Net cash used in by investing activities	(3,131,000,000)	(14,615,000,000)	(7,817,000,000)
Financing Activities:
Proceeds from debt financing, net of issuance costs	0	8,184,000,000	0
Proceeds from issuances of common stock	169,000,000	256,000,000	209,000,000
Repurchases of common stock	(546,000,000)	(1,583,000,000)	(1,749,000,000)
Repayments of debt and other obligations	(4,750,000,000)	(2,500,000,000)	(2,750,000,000)
Payment of dividends	(3,605,000,000)	(3,449,000,000)	(3,222,000,000)
Other	(145,000,000)	(138,000,000)	(122,000,000)
Net cash (used in) provided by financing activities	(8,877,000,000)	770,000,000	(7,634,000,000)
Effect of exchange rate changes on cash and cash equivalents	(35,000,000)	43,000,000	(2,000,000)
Net change in cash and cash equivalents	(659,000,000)	(5,634,000,000)	(6,309,000,000)
Cash and cash equivalents at beginning of period	5,997,000,000	11,631,000,000	17,940,000,000
Cash and cash equivalents at end of period	5,338,000,000	5,997,000,000	11,631,000,000
Supplemental disclosure of cash flow information:
Interest paid, net of amounts capitalized	979,000,000	951,000,000	982,000,000
Income taxes paid	$ 2,509,000,000	$ 2,639,000,000	$ 1,793,000,000

Organization and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Organization and Summary of Significant Accounting Policies

ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Overview

Gilead Sciences, Inc. (“Gilead,” “we,” “our” or “us”) is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. We are committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis and cancer. We operate in more than 35 countries worldwide, with headquarters in Foster City, California.

Our portfolio of marketed products includes AmBisome®, Atripla®, Biktarvy®, Cayston®, Complera®, Descovy®, Descovy for PrEP®, Emtriva®, Epclusa®, Eviplera®, Genvoya®, Harvoni®, Hepcludex® (bulevirtide), Hepsera®, Jyseleca® (filgotinib), Letairis®, Odefsey®, Ranexa®, Sovaldi®, Stribild®, Tecartus®, Trodelvy®, Truvada®, Truvada for PrEP®, Tybost®, Veklury®, Vemlidy®, Viread®, Vosevi®, Yescarta® and Zydelig®. The approval status of Hepcludex and Jyseleca vary worldwide, and Hepcludex and Jyseleca are not approved in the United States. We also sell and distribute authorized generic versions of Epclusa and Harvoni in the United States through our separate subsidiary, Asegua Therapeutics, LLC. In addition, we sell and distribute certain products through our corporate partners under collaborative agreements.

Basis of Presentation

The accompanying Consolidated Financial Statements include the accounts of Gilead, our wholly-owned subsidiaries and certain variable interest entities for which we are the primary beneficiary. All intercompany transactions have been eliminated. For consolidated entities where we own or are exposed to less than 100% of the economics, we record net income or loss attributable to noncontrolling interests in our Consolidated Statements of Income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties.

We assess whether we are the primary beneficiary of a variable interest entity (“VIE”) at the inception of the arrangement and at each reporting date. This assessment is based on our power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and our obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE. We did not have any material VIEs as of December 31, 2021.

Certain reclassifications have been made to prior periods in the Consolidated Financial Statements and accompanying notes to conform with the current presentation. Beginning 2020, acquired in-process research and development (“IPR&D”) expenses are reported separately from Research and development expenses on our Consolidated Statements of Income. Our Consolidated Statements of Income for the year ended December 31, 2019 was conformed to separately present acquired IPR&D expenses.

Segment Information

We have one operating segment which primarily focuses on the discovery, development and commercialization of innovative medicines in areas of unmet medical need. Our Chief Executive Officer, as the chief operating decision-maker (“CODM”), manages and allocates resources to the operations of our company on an entity-wide basis. Managing and allocating resources on an entity-wide basis enables our CODM to assess the overall level of resources available and how to best deploy these resources across functions and research and development (“R&D”) projects based on unmet medical need and, as necessary, reallocate resources among our internal R&D portfolio and external opportunities to best support the long-term growth of our business. See Note 2. Revenues for a summary of disaggregated revenues by product and geographic region.

Significant Accounting Policies, Estimates and Judgments

The preparation of these Consolidated Financial Statements in accordance with U.S. generally accepted accounting principles requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosures. On an ongoing basis, we evaluate our significant accounting policies and estimates. We base our estimates on historical experience and on various market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are assessed each period and updated to reflect current information, such as the economic considerations related to the impact that the coronavirus disease (“COVID-19”) could have on our significant accounting estimates. Actual results may differ significantly from these estimates.

Revenue Recognition

Product Sales

We recognize revenue from product sales when control of the product transfers, generally upon shipment or delivery, to the customer, or in certain cases, upon the corresponding sales by our customer to a third party. The revenues are recognized net of estimated government and other rebates and chargebacks, cash discounts for prompt payment, distributor fees, sales return provisions and other related deductions. These deductions to product sales are referred to as gross-to-net deductions and are estimated and recorded in the period in which the related product sales occur. Our payment terms to customers generally range from 30 to 90 days; however, payment terms differ by jurisdiction, by customer and, in some instances, by type of product. Revenues from product sales, net of gross-to-net deductions, are recorded only to the extent a significant reversal in the amount of cumulative revenue recognized is not probable of occurring when the uncertainty associated with gross-to-net deductions is subsequently resolved. Taxes assessed by governmental authorities and collected from customers are excluded from product sales. If we expect, at contract inception, that the period between the transfer of control and corresponding payment from the customer will be one year or less, we do not adjust the amount of consideration for the effects of a financing component.

Gross-to-Net Deductions

Rebates and Chargebacks

Government and other rebates and chargebacks include amounts payable to payers and healthcare providers under various programs, and may vary by product, by payer and individual payer plans. Rebates and chargebacks are based on contractual arrangements or statutory requirements which may vary by product, payer and individual payer plans. For qualified programs that can purchase our products through wholesalers or other distributors at a lower contractual price, the wholesalers or distributors charge back to us the difference between their acquisition cost and the lower contractual price.

Rebates and chargebacks are estimated primarily based on product sales, and expected payer mix and discount rates, which require significant estimates and judgment. Additionally, in developing our estimates, we consider: historical and estimated payer mix; statutory discount requirements and contractual terms; historical claims experience and processing time lags; estimated patient population; known market events or trends; market research; channel inventory data obtained from our major U.S. wholesalers; and other pertinent internal or external information. We assess and update our estimates each reporting period to reflect actual claims and other current information.

Government and other chargebacks that are payable to our direct customers are generally classified as reductions of Accounts receivable on our Consolidated Balance Sheets. Government and other rebates that are payable to third party payers and healthcare providers are recorded in Accrued government and other rebates on our Consolidated Balance Sheets.

Cash Discounts

We estimate cash discounts based on contractual terms, historical customer payment patterns and our expectations regarding future customer payment patterns.

Distributor Fees

Under our inventory management agreements with our significant U.S. wholesalers, we pay the wholesalers a fee primarily for compliance with certain contractually determined covenants such as the maintenance of agreed upon inventory levels. These distributor fees are based on a contractually determined fixed percentage of sales.

Allowance for Sales Returns

Allowances are made for estimated sales returns by our customers and are recorded in the period the related revenue is recognized. We typically permit returns if the product is damaged, defective, or otherwise cannot be used by the customer. In the United States, we typically permit returns six months prior to and up to one year after the product expiration date. Outside the United States, returns are only allowed in certain countries on a limited basis.

Our estimates of sales returns are based primarily on analysis of our historical product return patterns, industry information reporting the return rates for similar products and contractual agreement terms. We also take into consideration known or expected changes in the marketplace specific to each product.

Shipping and Handling

Shipping and handling activities are considered to be fulfillment activities and not considered to be a separate performance obligation.

Royalty, Contract and Other Revenues

Royalty revenue is recognized in the period in which the obligation is satisfied and the corresponding sales by our corporate partners occur.

Research and Development Expenses

R&D expenses consist primarily of clinical studies performed by contract research organizations (“CROs”), materials and supplies, payments under collaborative and other arrangements including milestone payments, licenses and fees, expense reimbursements to the collaboration partners, personnel costs including salaries, benefits and stock-based compensation expense, and overhead allocations consisting of various support and infrastructure costs. Milestone payments made to third-party collaborators are expensed as incurred up to the point of regulatory approval. Milestone payments made upon regulatory approval are capitalized and amortized over the remaining useful life of the related product. From time to time, we enter into development and collaboration agreements in which we share expenses with a collaborative partner. We record payments received from our collaborative partners for their share of the development costs as a reduction of R&D expenses.

We charge R&D costs, including clinical study costs, to expense when incurred. Clinical study costs are a significant component of R&D expenses. Most of our clinical studies are performed by third-party CROs. We monitor levels of performance under each significant contract including the extent of patient enrollment and other activities through communications with our CROs. We accrue costs for clinical studies performed by CROs over the service periods specified in the contracts and adjust our estimates, if required, based upon our ongoing review of the level of effort and costs actually incurred by the CROs. All of our material CRO contracts are terminable by us upon written notice and we are generally only liable for actual services completed by the CRO and certain non-cancelable expenses incurred at any point of termination. Payments we make for R&D services prior to the services being rendered are recorded as prepaid assets in our Consolidated Balance Sheets and are expensed as the services are provided.

Acquired In-Process Research and Development Expenses

Acquired IPR&D expenses reflect IPR&D impairments as well as the initial costs of externally developed IPR&D projects, acquired directly in a transaction other than a business combination, that do not have an alternative future use, including upfront payments related to various collaborations and the initial costs of rights to IPR&D projects. The acquired IPR&D is expensed on acquisition date. Future costs to develop these IPR&D projects are recorded in Research and development expenses on our Consolidated Statements of Income as incurred.

Selling, General and Administrative Expenses

Selling, general and administrative (“SG&A”) expenses relate to sales and marketing, finance, human resources, legal and other administrative activities. SG&A expenses consist primarily of personnel costs, facilities and overhead costs, outside marketing, advertising and legal expenses, and other general and administrative costs. SG&A expenses also include the Branded Prescription Drug (“BPD”) fee. In the United States, we, along with other pharmaceutical manufacturers of branded drug products, are required to pay a portion of the BPD fee, which is estimated based on select government sales during the prior year as a percentage of total industry government sales.

We expense the costs of advertising, including promotional expenses, as incurred. Advertising expenses were $735 million, $795 million and $784 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Cash and Cash Equivalents

We consider highly liquid investments with insignificant interest rate risk and an original maturity of three months or less on the purchase date to be cash equivalents.

Marketable and Non-Marketable Securities

Marketable Debt Securities

We determine the appropriate classification of our marketable debt securities at the time of purchase and reevaluate such designation at each balance sheet date. All of our marketable debt securities are considered available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term marketable debt securities or long-term marketable debt securities. Unrealized gains and losses on available-for-sale debt securities are excluded from net income and reported in Accumulated other comprehensive income (loss) (“AOCI”) as a separate component of stockholders’ equity. Other income (expense), net, includes interest, amortization of purchase premiums and discounts, realized gains and losses on sales of securities and expected credit losses, if any. The cost of securities sold is based on the specific identification method. We regularly review our investments for declines in fair value below their amortized cost basis to determine whether the impairment is due to credit-related factors or noncredit-related factors. Our review includes the creditworthiness of the security issuers, the severity of the unrealized losses, whether we have the intent to sell the securities and whether it is more likely than not that we will be required to sell the securities before the recovery of their amortized cost bases. When we determine that a portion of the unrealized loss is due to an expected credit loss, we recognize the loss amount in Other income (expense), net, with a corresponding allowance against the carrying value of the security we hold. The portion of the unrealized loss related to factors other than credit losses is recognized in AOCI.

Marketable and Non-Marketable Equity Securities

Investments in equity securities, other than equity method investments, are recorded at fair market value if fair value is readily determinable, and unrealized gains and losses are included in Other income (expense), net on our Consolidated Statements of Income.

For investments in entities over which we have significant influence but do not meet the requirements for consolidation and have not elected the fair value option, we use the equity method of accounting with our share of the underlying income or loss of such entities reported in Other income (expense), net on our Consolidated Statements of Income. We have elected the fair value option to account for our equity investments in Arcus Biosciences, Inc. (“Arcus”) and Galapagos NV (“Galapagos”) over which we have significant influence. We believe the fair value option best reflects the underlying economics of these investments. See Note 11. Collaborations and Other Arrangements for additional information.

Equity securities without readily determinable fair values are recorded using the measurement alternative of cost less impairment, if any, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer. Certain investments in equity securities of non-public companies are accounted for using the equity method based on our ownership percentage and other factors that indicate we have significant influence over the investee. See Note 11. Collaborations and Other Arrangements for additional information.

Our investments in equity securities are recorded in Prepaid and other current assets or Other long-term assets on our Consolidated Balance Sheets. We regularly review our securities for indicators of impairment.

Concentrations of Risk

We are subject to credit risk from our portfolio of cash equivalents and marketable securities. Under our investment policy, we limit amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. We are not exposed to any significant concentrations of credit risk from these financial instruments. The goals of our investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after-tax rate of return.

We are also subject to credit risk from our accounts receivable related to our product sales. Trade accounts receivable are recorded net of allowances for wholesaler chargebacks related to government and other programs, cash discounts for prompt payment and credit losses. Estimates of our allowance for credit losses consider a number of factors including existing contractual payment terms, individual customer circumstances, historical payment patterns of our customers, a review of the local economic environment and its potential impact on expected future customer payment patterns and government funding and reimbursement practices. The majority of our trade accounts receivable arises from product sales in the United States and Europe. Additions to the allowance for credit losses, write-offs and recoveries of customer receivables were not material for the years ended December 31, 2021, 2020 and 2019.

Inventories

Inventories are recorded at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. We periodically review our inventories to identify obsolete, slow-moving, excess or otherwise unsaleable items. If obsolete, slow-moving, excess or unsaleable items are observed and there are no alternate uses for the inventory, we record a write-down to net realizable value through a charge to Cost of goods sold on our Consolidated Statements of Income. The determination of net realizable value requires judgment, including consideration of many factors, such as estimates of future product demand, product net selling prices, current and future market conditions and potential product obsolescence, among others.

When future commercialization is considered probable and the future economic benefit is expected to be realized, based on management’s judgment, we capitalize pre-launch inventory costs prior to regulatory approval. A number of factors are considered, including the current status in the regulatory approval process, potential impediments to the approval process such as safety or efficacy, anticipated R&D initiatives that could impact the indication in which the compound will be used, viability of commercialization and marketplace trends.

Property, Plant and Equipment

Property, plant and equipment is stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method. Repairs and maintenance costs are expensed as incurred. Estimated useful lives in years are generally as follows:


Description			Estimated Useful Life
Buildings and improvements			Shorter of 35 years or useful life
Laboratory and manufacturing equipment			4-10
Office, computer equipment and other			3-15
Leasehold improvements			Shorter of useful life or lease term

Leases

We determine if an arrangement contains a lease at inception. Right-of-use assets and lease liabilities are recognized at the commencement date based on the present value of the lease payments over the lease term, which is the non-cancelable period stated in the contract adjusted for any options to extend or terminate when it is reasonably certain that we will exercise that option. Right-of-use assets are adjusted for prepaid lease payments, lease incentives and initial direct costs incurred. Operating lease expense for the minimum lease payments is recognized on a straight-line basis over the lease term.

We account for lease and nonlease components in our lease agreements as a single lease component in determining lease assets and liabilities. In addition, we do not recognize the right-of-use assets and liabilities for leases with lease terms of one year or less.

As most of our operating leases do not provide an implicit interest rate, we generally utilize a collateralized incremental borrowing rate, applied in a portfolio approach when relevant, based on the information available at the commencement date to determine the lease liability.

Acquisitions

We account for business combinations using the acquisition method of accounting, which generally requires that assets acquired, including IPR&D projects, and liabilities assumed be recorded at their fair values as of the acquisition date on our Consolidated Balance Sheets. Any excess of consideration over the fair value of net assets acquired is recorded as goodwill. The determination of estimated fair value requires us to make significant estimates and assumptions. As a result, we may record adjustments to the fair values of assets acquired and liabilities assumed within the measurement period, which may be up to one year from the acquisition date, with the corresponding offset to goodwill. Transaction costs associated with business combinations are expensed as they are incurred.

When we determine net assets acquired do not meet the definition of a business combination under the acquisition method of accounting, the transaction is accounted for as an acquisition of assets and, therefore, no goodwill is recorded and contingent consideration, such as payments upon achievement of various developmental, regulatory and commercial milestones, generally is not recognized at the acquisition date. In an asset acquisition, upfront payments allocated to IPR&D projects at the acquisition date and subsequent milestone payments are expensed as incurred on our Consolidated Statements of Income unless there is an alternative future use.

Goodwill and Intangible Assets

Goodwill represents the excess of the consideration transferred over the estimated fair value of assets acquired and liabilities assumed in a business combination. Intangible assets are measured at their respective fair values as of the acquisition date and may be subject to adjustment within the measurement period, which may be up to one year from the acquisition date. Intangible assets related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. We do not amortize goodwill and intangible assets with indefinite useful lives. Goodwill and indefinite-lived intangible assets are tested for impairment annually or more frequently if events or changes in circumstances indicate that it is more likely than not that the assets are impaired.

When development is successfully completed, which generally occurs when regulatory approval is obtained, the associated assets are deemed finite-lived and amortized over their respective estimated useful lives beginning at that point in time. Intangible assets with finite useful lives are amortized over their estimated useful lives, primarily on a straight-line basis, and are reviewed for impairment when facts or circumstances indicate that the carrying value of these assets may not be recoverable.

Impairment of Long-Lived Assets

Long-lived assets, including property, plant and equipment and finite-lived intangible assets, are reviewed for impairment whenever facts or circumstances either internally or externally may indicate that the carrying value of an asset may not be recoverable. Should there be an indication of impairment, we test for recoverability by comparing the estimated undiscounted future cash flows expected to result from the use of the asset to the carrying amount of the asset or asset group. If the asset or asset group is determined to be impaired, any excess of the carrying value of the asset or asset group over its estimated fair value is recognized as an impairment loss.

Valuation of Contingent Consideration Resulting from a Business Combination

In connection with certain acquisitions, we may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. We record contingent consideration resulting from a business combination at its fair value on the acquisition date. Each reporting period thereafter, we revalue these obligations and record increases or decreases in their fair value in Research and development expenses on our Consolidated Statements of Income until such time that the related product candidate receives marketing approval.

Increases or decreases in fair value of the contingent consideration liabilities can result from updates to assumptions such as the expected timing or probability of achieving the specified milestones, changes in projected revenues or changes in discount rates. Significant judgment is employed in determining these assumptions as of the acquisition date and for each subsequent period. Updates to assumptions could have a significant impact on our results of operations in any given period. Actual results may differ from estimates.

Foreign Currency Translation, Transaction Gains and Losses, and Hedging Contracts

Non-U.S. entity operations are recorded in the functional currency of each entity. Results of operations for non-U.S. dollar functional currency entities are translated into U.S. dollars using average currency rates. Assets and liabilities are translated using currency rates at period end. Foreign currency translation adjustments are recorded as a component of AOCI within stockholders’ equity. Foreign currency transaction gains and losses are recorded in Other income (expense), net, on our Consolidated Statements of Income. Net foreign currency transaction gains and losses were not material for the years ended December 31, 2021, 2020 and 2019.

We hedge a portion of our foreign currency exposures related to outstanding monetary assets and liabilities as well as forecasted product sales using foreign currency exchange forward contracts. In general, the market risk related to these contracts is offset by corresponding gains and losses on the hedged transactions. The credit risk associated with these contracts is driven by changes in interest and currency exchange rates and, as a result, varies over time. By working only with major banks and closely monitoring current market conditions, we seek to limit the risk that counterparties to these contracts may be unable to perform. We also seek to limit our risk of loss by entering into contracts that permit net settlement at maturity. Therefore, our overall risk of loss in the event of a counterparty default is limited to the amount of any unrealized gains on outstanding contracts (i.e., those contracts that have a positive fair value) at the date of default. We do not enter into derivative contracts for trading purposes.

Fair Value of Financial Instruments

We apply fair value accounting for all financial and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. We define fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities which are required to be recorded at fair value, we consider the principal or most advantageous market in which we would transact and the market-based risk measurements or assumptions that market participants would use in pricing the asset or liability, such as risks inherent in valuation techniques, transfer restrictions and credit risks.

Derivative Financial Instruments

We recognize all derivative instruments as either assets or liabilities at fair value on our Consolidated Balance Sheets. Unrealized changes in the fair value of derivatives designated as part of a hedge transaction are recorded in AOCI. The unrealized gains or losses in AOCI are reclassified into Product sales on our Consolidated Statements of Income when the respective hedged transactions affect earnings. Changes in the fair value of derivatives that are not part of a hedge transaction are recorded each period in Other income (expense), net on our Consolidated Statements of Income.

We assess, both at inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are effective in offsetting the changes in cash flows or fair values of the hedged items. If we determine that a forecasted transaction is probable of not occurring, we discontinue hedge accounting for the affected portion of the hedge instrument, and any related unrealized gain or loss on the contract is recognized in Other income (expense), net on our Consolidated Statements of Income.

Share-Based Compensation

We provide share-based compensation in the form of various types of equity-based awards, including restricted stock units (“RSU”s), performance share awards or units (“PSU”s) and stock options. Compensation expense is recognized on the Consolidated Statements of Income based on the estimated fair value of the award on the grant date. The estimated fair value of RSUs is based on the closing price of our common stock. For PSUs, depending on the terms of the award, fair value on the date of grant is determined based on either the Monte Carlo valuation methodology or the closing stock price on the date of grant. For stock option awards, estimated fair value is based on the Black-Scholes option valuation model.

Contingencies

We are a party to various legal actions. We recognize accruals for such actions to the extent that we conclude that a loss is both probable and reasonably estimable. We accrue the best estimate of loss within a range; however, if no estimate in the range is better than any other, then we accrue the minimum amount in the range. If we determine that a material loss is reasonably possible, we disclose the possible loss or range of loss, or that the amount of loss cannot be estimated at this time.

Income Taxes

Our income tax provision is computed under the liability method. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Significant estimates are required in determining our provision for income taxes. Some of these estimates are based on interpretations of applicable tax laws or regulations.

We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by tax authorities based on the technical merits of the position. The tax benefit recognized in the Consolidated Financial Statements for a particular tax position is based on the largest benefit that is more likely than not to be realized. The amount of unrecognized tax benefits (“UTB”) is adjusted as appropriate for changes in facts and circumstances, such as significant amendments to existing tax law, new regulations or interpretations by tax authorities, new information obtained during a tax examination or resolution of an examination. We recognize both accrued interest and penalties, where appropriate, related to UTB in Income tax (expense) benefit on our Consolidated Statements of Income.

We have elected to account for the tax on Global Intangible Low-Taxed Income, enacted as part of the Tax Cuts and Jobs Act, as a component of tax expense in the period in which the tax is incurred.

Other Significant Accounting Policies

Our other significant accounting policies are described in the remaining appropriate Notes to the Consolidated Financial Statements.

Revenues

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Revenues

REVENUES

Disaggregation of Revenues

Revenues were as follows:


	Year Ended December 31, 2021								Year Ended December 31, 2020								Year Ended December 31, 2019
(in millions)	U.S.		Europe		Other International		Total		U.S.		Europe		Other International		Total		U.S.		Europe		Other International		Total
Product Sales:
HIV
Atripla	$	121	$	12	$	12	$	145	$	307	$	21	$	21	$	349	$	501	$	60	$	39	$	600
Biktarvy	7,049		969		606		8,624		6,095		735		429		7,259		4,225		370		143		4,738
Complera/Eviplera	102		142		14		258		89		159		21		269		160		214		32		406
Descovy	1,397		164		139		1,700		1,526		197		138		1,861		1,078		255		167		1,500
Genvoya	2,267		391		221		2,879		2,605		490		243		3,338		2,984		664		283		3,931
Odefsey	1,076		440		52		1,568		1,172		450		50		1,672		1,180		438		37		1,655
Stribild	132		43		14		189		125		54		17		196		268		75		26		369
Truvada	314		22		35		371		1,376		27		45		1,448		2,640		101		72		2,813
Revenue share - Symtuza(1)	355		165		11		531		331		149		8		488		249		130		—		379
Other HIV(2)	15		18		17		50		25		5		28		58		30		5		12		47
Total HIV	12,828		2,366		1,121		16,315		13,651		2,287		1,000		16,938		13,315		2,312		811		16,438

Veklury	3,640		1,095		830		5,565		2,026		607		178		2,811		—		—		—		—

Hepatitis C virus (“HCV”)
Ledipasvir/ Sofosbuvir(3)	84		31		97		212		92		29		151		272		312		71		260		643
Sofosbuvir/Velpatasvir(4)	815		316		331		1,462		864		337		398		1,599		971		553		441		1,965
Other HCV(5)	119		74		14		207		132		48		13		193		182		118		28		328
Total HCV	1,018		421		442		1,881		1,088		414		562		2,064		1,465		742		729		2,936

Hepatitis B virus (“HBV”) / Hepatitis Delta virus (“HDV”)
Vemlidy	384		34		396		814		356		29		272		657		309		21		158		488
Viread	11		28		72		111		14		34		137		185		32		69		142		243
Other HBV/HDV(6)	2		42		—		44		10		8		—		18		2		9		—		11
Total HBV/HDV	397		104		468		969		380		71		409		860		343		99		300		742

Cell Therapy
Tecartus	136		40		—		176		34		10		—		44		—		—		—		—
Yescarta	406		253		36		695		362		191		10		563		373		83		—		456
Total Cell Therapy	542		293		36		871		396		201		10		607		373		83		—		456

Trodelvy	370		10		—		380		49		—		—		49		—		—		—		—

Other
AmBisome	39		274		227		540		61		230		145		436		37		234		136		407
Letairis	206		—		—		206		314		—		—		314		618		—		—		618
Ranexa	10		—		—		10		9		—		—		9		216		—		—		216
Zydelig	26		35		1		62		31		39		2		72		47		54		2		103
Other(7)	100		80		29		209		136		45		14		195		151		43		9		203
Total Other	381		389		257		1,027		551		314		161		1,026		1,069		331		147		1,547
Total product sales	19,176		4,678		3,154		27,008		18,141		3,894		2,320		24,355		16,565		3,567		1,987		22,119
Royalty, contract and other revenues	91		196		10		297		76		241		17		334		80		244		6		330
Total revenues	$	19,267	$	4,874	$	3,164	$	27,305	$	18,217	$	4,135	$	2,337	$	24,689	$	16,645	$	3,811	$	1,993	$	22,449

_______________________________

(1) Represents our revenue from cobicistat (“C”), emtricitabine (“FTC”) and tenofovir alafenamide (“TAF”) in Symtuza (darunavir/C/FTC/TAF), a fixed dose combination product commercialized by Janssen Sciences Ireland Unlimited Company (“Janssen”).

(2) Includes Emtriva and Tybost.

(3) Amounts consist of sales of Harvoni and the authorized generic version of Harvoni sold by our separate subsidiary, Asegua Therapeutics LLC.

(4) Amounts consist of sales of Epclusa and the authorized generic version of Epclusa sold by our separate subsidiary, Asegua Therapeutics LLC.

(5) Includes Vosevi and Sovaldi.

(6) Includes Hepcludex and Hepsera.

(7) Includes Cayston and Jyseleca.

Revenues From Major Customers

The following table summarizes revenues from each of our customers who individually accounted for 10% or more of our total revenues:


	Year Ended December 31,
(as a percentage of total revenues)	2021		2020		2019
AmerisourceBergen Corporation	23	%	27	%	21	%
Cardinal Health, Inc.	22	%	21	%	21	%
McKesson Corporation	20	%	20	%	22	%

Revenues Recognized from Performance Obligations Satisfied in Prior Periods

Revenues recognized from performance obligations satisfied in prior years related to our revenue share with Janssen, as described in Note 11. Collaborations and Other Arrangements, and royalties for licenses of our intellectual property were $851 million, $841 million and $741 million for the years ended December 31, 2021, 2020 and 2019, respectively.

Revenues from product sales, net of gross-to-net deductions, are recorded only to the extent a significant reversal in the amount of cumulative revenue recognized is not probable of occurring when the uncertainty associated with gross-to-net deductions is subsequently resolved. Estimates are assessed each period and updated to reflect current information. Changes in estimates related to sales made in prior years resulted in $856 million, $101 million and $257 million increase in revenues for the years ended December 31, 2021, 2020 and 2019, respectively. This was primarily related to changes in estimates for accrued government and other rebates and allowances for sales returns upon product expiration.

Contract Balances

Our contract assets, which consist of unbilled amounts primarily from arrangements where the licensing of intellectual property is the only or predominant performance obligation, totaled $174 million and $198 million as of December 31, 2021 and 2020, respectively. Contract liabilities, which generally result from receipt of advance payment before our performance under the contract, were not material as of December 31, 2021 and 2020, respectively. Revenue expected to be recognized in the future from contract liabilities as the related performance obligations are satisfied is not expected to be material in any one year.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-URI http://asc.fasb.org/topic&trid=49130388

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130551-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130556-203045

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 12
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130558-203045

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123351226&loc=SL49130554-203045

+ Details

Fair Value Measurements

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

We determine the fair value of financial and non-financial assets and liabilities using the fair value hierarchy, which establishes three levels of inputs that may be used to measure fair value, as follows:

•Level 1 inputs include quoted prices in active markets for identical assets or liabilities;

•Level 2 inputs include observable inputs other than Level 1 inputs, such as quoted prices for similar assets or liabilities; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability; and

•Level 3 inputs include unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the underlying asset or liability. Our Level 3 assets and liabilities include those whose fair value measurements are determined using pricing models, discounted cash flow methodologies or similar valuation techniques and significant management judgment or estimation.

Our financial instruments consist primarily of cash and cash equivalents, marketable debt securities, accounts receivable, foreign currency exchange contracts, equity securities, accounts payable and short-term and long-term debt. Cash and cash equivalents, marketable debt securities, certain equity securities, and foreign currency exchange contracts are reported at their respective fair values on our Consolidated Balance Sheets. Equity securities without readily determinable fair values are recorded using the measurement alternative of cost less impairment, if any, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer. Short-term and long-term debt are reported at their amortized costs on our Consolidated Balance Sheets. The remaining financial instruments are reported on our Consolidated Balance Sheets at amounts that approximate current fair values. There were no transfers between Level 1, Level 2 and Level 3 in the periods presented.

The following table summarizes the types of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy:


	December 31, 2021								December 31, 2020
(in millions)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale debt securities:
U.S. treasury securities	$	407	$	—	$	—	$	407	$	309	$	—	$	—	$	309
U.S. government agencies securities	—		4		—		4		—		—		—		—
Non-U.S. government securities	—		50		—		50		—		43		—		43
Certificates of deposit	—		249		—		249		—		216		—		216
Corporate debt securities	—		1,363		—		1,363		—		1,142		—		1,142
Residential mortgage and asset-backed securities	—		424		—		424		—		316		—		316
Equity securities:
Money market funds	3,661		—		—		3,661		4,361		—		—		4,361
Equity investment in Galapagos(1)	931		—		—		931		1,648		—		—		1,648
Equity investment in Arcus(1)	559		—		—		559		212		—		—		212
Other publicly traded equity securities	331		—		—		331		531		—		—		531
Deferred compensation plan	261		—		—		261		218		—		—		218
Foreign currency derivative contracts	—		80		—		80		—		12		—		12
Total	$	6,150	$	2,170	$	—	$	8,320	$	7,279	$	1,729	$	—	$	9,008
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	$	—	$	—	$	317	$	317	$	—	$	—	$	—	$	—
Deferred compensation plan	261		—		—		261		218		—		—		218
Foreign currency derivative contracts	—		5		—		5		—		121		—		121
Total	$	261	$	5	$	317	$	583	$	218	$	121	$	—	$	339

_______________________________

(1) See Note 11. Collaborations and Other Arrangements for additional information.

Equity Securities

The following table summarizes the classification of our equity securities measured at fair value on a recurring basis on our Consolidated Balance Sheets:


(in millions)	December 31, 2021		December 31, 2020
Cash and cash equivalents	$	3,661	$	4,361
Prepaid and other current assets	885		853
Other long-term assets	1,197		1,756
Total	$	5,743	$	6,970

Changes in the fair value of equity securities resulted in net unrealized losses of $610 million and $1.7 billion and net unrealized gains of $1.2 billion for the years ended December 31, 2021, 2020 and 2019 respectively, which were included in Other income (expense), net, on our Consolidated Statements of Income.

Other Equity Securities

Equity method investments and other equity investments without readily determinable fair values were $338 million and $262 million as of December 31, 2021 and 2020, respectively, and were excluded from the above tables. These amounts were included in Other long-term assets on our Consolidated Balance Sheets.

Related Party Transaction

During the second quarter of 2021, we donated certain equity securities at fair value to the Gilead Foundation, a California nonprofit organization (the “Foundation”). The Foundation is a related party as certain officers of the company also serve as directors of the Foundation. The donation expense of $212 million was recorded within Selling, general and administrative expenses on our Consolidated Statements of Income for the year ended December 31, 2021.

Level 2 Inputs

We estimate the fair values of Level 2 investments by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income-based and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate the fair value. These inputs include reported trades of and broker/dealer quotes on the same or similar securities, issuer credit spreads, benchmark securities, prepayment/default projections based on historical data and other observable inputs.

For our marketable securities, we review trading activity and pricing as of the measurement date. When sufficient quoted pricing for identical securities is not available, we use market pricing and other observable market inputs for similar securities obtained from various third-party data providers. These inputs either represent quoted prices for similar assets in active markets or have been derived from observable market data.

Substantially all of our foreign currency derivative contracts have maturities within an 18-month time horizon and all are with counterparties that have a minimum credit rating of A- or equivalent by S&P Global Ratings, Moody’s Investors Service, Inc. or Fitch Ratings, Inc. We estimate the fair values of these contracts by taking into consideration the valuations obtained from a third-party valuation service that utilizes an income-based industry standard valuation model for which all significant inputs are observable, either directly or indirectly. These inputs include foreign currency exchange rates, London Interbank Offered Rates (“LIBOR”) and swap rates. These inputs, where applicable, are observable at commonly quoted intervals.

The total estimated fair values of our aggregate short-term and long-term debt, determined using Level 2 inputs based on their quoted market values, were approximately $28.6 billion and $34.6 billion as of December 31, 2021 and 2020, respectively, and the carrying values were $25.6 billion and $30.3 billion as of December 31, 2021 and 2020, respectively.

Level 3 Inputs

In connection with our first quarter 2021 acquisition of MYR, we measured assets acquired and liabilities assumed at fair value on a nonrecurring basis, except for the liability for contingent consideration. The estimated fair value of the liability for contingent consideration was $341 million and $317 million as of the acquisition date and December 31, 2021, respectively. The change in estimated fair value from the acquisition date was primarily due to the effect of foreign exchange remeasurement. The contingent consideration was estimated using probability-weighted scenarios for U.S. Food and Drug Administration (“FDA”) approval of Hepcludex. See Note 6. Acquisitions for additional information.

In connection with our fourth quarter 2020 acquisition of Immunomedics, Inc. (“Immunomedics”), we measured assets acquired and liabilities assumed at fair value on a nonrecurring basis. The liability assumed related to the sale of future royalties is subsequently amortized using the effective interest method over the remaining estimated life. The fair values of the liability related to the sale of future royalties were $1.3 billion and $1.1 billion as of December 31, 2021 and 2020, respectively, and the carrying value was $1.1 billion as of December 31, 2021 and 2020. See Note 6. Acquisitions and Note 12. Debt and Credit Facilities for additional information.

In 2020, in connection with collaborations and other equity arrangements we entered into with Pionyr Immunotherapeutics Inc. (“Pionyr”) and Tizona Therapeutics, Inc. (“Tizona”), we also measured fair values of our exclusive options to acquire the remaining outstanding capital stock of Pionyr and Tizona on a nonrecurring basis. See Note 11. Collaborations and Other Arrangements for additional information.

In 2019, we measured IPR&D intangible assets acquired in connection with the acquisition of Kite Pharma, Inc. (“Kite”) at fair value on a nonrecurring basis, and recognized a pre-tax impairment charge of $800 million. The fair values of the acquired IPR&D assets are estimated based on probability-adjusted discounted cash flow calculations using Level 3 fair value measurements, and inputs include estimated revenues, costs, probability of technical and regulatory success and discount rates. Amounts capitalized as IPR&D are subject to impairment testing until the completion or abandonment of the associated R&D efforts. See Note 9. Goodwill and Intangible Assets for additional information.

Our policy is to recognize transfers into or out of Level 3 classification as of the actual date of the event or change in circumstances that caused the transfer. There were no transfers between Level 1, Level 2 and Level 3 in the periods presented.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Available-for-Sale Debt Securities

12 Months Ended

Dec. 31, 2021

Debt Securities, Available-for-sale [Abstract]

Available-for-sale Debt Securities

AVAILABLE-FOR-SALE DEBT SECURITIES

The following table summarizes our available-for-sale debt securities:


	December 31, 2021								December 31, 2020
(in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. treasury securities	$	408	$	—	$	(1)	$	407	$	308	$	1	$	—	$	309
U.S. government agencies securities	4		—		—		4		—		—		—		—
Non-U.S. government securities	50		—		—		50		43		—		—		43
Certificates of deposit	249		—		—		249		216		—		—		216
Corporate debt securities	1,365		—		(2)		1,363		1,140		2		—		1,142
Residential mortgage and asset-backed securities	425		—		(1)		424		316		—		—		316
Total	$	2,501	$	—	$	(4)	$	2,497	$	2,023	$	3	$	—	$	2,026

The following table summarizes the classification of our available-for-sale debt securities in our Consolidated Balance Sheets:


(in millions)	December 31, 2021		December 31, 2020
Cash and cash equivalents	$	6	$	113
Short-term marketable debt securities	1,182		1,411
Long-term marketable debt securities	1,309		502
Total	$	2,497	$	2,026

The following table summarizes our available-for-sale debt securities by contractual maturity:


	December 31, 2021
(in millions)	Amortized Cost		Fair Value
Within one year	$	1,189	$	1,188
After one year through five years	1,288		1,286
After five years	24		23
Total	$	2,501	$	2,497

We held a total of 534 and 75 positions which were in unrealized loss positions as of December 31, 2021 and 2020, respectively. Aggregated gross unrealized losses on available-for-sale debt securities were not material for the years ended December 31, 2021 and 2020. No impairment was recognized for the years ended December 31, 2021, 2020 and 2019.

Derivative Financial Instruments

12 Months Ended

Dec. 31, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments

DERIVATIVE FINANCIAL INSTRUMENTS

Our operations in foreign countries expose us to market risk associated with foreign currency exchange rate fluctuations between the U.S. dollar and various foreign currencies, primarily the Euro. To manage this risk, we may hedge a portion of our foreign currency exposures related to outstanding monetary assets and liabilities as well as forecasted product sales using foreign currency exchange forward or option contracts. In general, the market risk related to these contracts is offset by corresponding gains and losses on the hedged transactions. The credit risk associated with these contracts is driven by changes in interest and currency exchange rates, and as a result, varies over time. By working only with major banks and closely monitoring current market conditions, we seek to limit the risk that counterparties to these contracts may be unable to perform. We also seek to limit our risk of loss by entering into contracts that permit net settlement at maturity. Therefore, our overall risk of loss in the event of a counterparty default is limited to the amount of any unrealized gains on outstanding contracts (i.e., those contracts that have a positive fair value) at the date of default. We do not enter into derivative contracts for trading purposes.

We hedge our exposure to foreign currency exchange rate fluctuations for certain monetary assets and liabilities that are denominated in a non-functional currency. The derivative instruments we use to hedge this exposure are not designated as hedges, and as a result, changes in their fair value are recorded in Other income (expense), net, on our Consolidated Statements of Income.

We hedge our exposure to foreign currency exchange rate fluctuations for forecasted product sales that are denominated in a non-functional currency. The derivative instruments we use to hedge this exposure are designated as cash flow hedges and have maturities of 18 months or less. Upon executing a hedging contract and each reporting period thereafter, we assess hedge effectiveness using regression analysis. The unrealized gains or losses in AOCI are reclassified into Product sales on our Consolidated Statements of Income when the respective hedged transactions affect earnings. The majority of gains and losses related to the hedged forecasted transactions reported in AOCI as of December 31, 2021 are expected to be reclassified to Product sales within 12 months.

The cash flow effects of our derivative contracts for the years ended December 31, 2021, 2020 and 2019 were included within Net cash provided by operating activities on our Consolidated Statements of Cash Flows.

We had notional amounts on foreign currency exchange contracts outstanding of $2.9 billion and $2.4 billion as of December 31, 2021 and 2020, respectively.

While all our derivative contracts allow us the right to offset assets and liabilities, we have presented amounts on a gross basis. The following table summarizes the classification and fair values of derivative instruments in our Consolidated Balance Sheets:


	December 31, 2021
	Derivative Assets			Derivative Liabilities
(in millions)	Classification	Fair Value		Classification	Fair Value
Derivatives designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	$	75	Accrued and other current liabilities	$	4
Foreign currency exchange contracts	Other long-term assets	5		Other long-term obligations	1
Total derivatives designated as hedges		80			5
Derivatives not designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	—		Accrued and other current liabilities	—
Total derivatives not designated as hedges		—			—
Total derivatives		$	80		$	5


	December 31, 2020
	Derivative Assets			Derivative Liabilities
(in millions)	Classification	Fair Value		Classification	Fair Value
Derivatives designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	$	—	Accrued and other current liabilities	$	113
Foreign currency exchange contracts	Other long-term assets	—		Other long-term obligations	7
Total derivatives designated as hedges		—			120
Derivatives not designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	12		Accrued and other current liabilities	1
Total derivatives not designated as hedges		12			1
Total derivatives		$	12		$	121

The following table summarizes the effect of our foreign currency exchange contracts on our Consolidated Financial Statements:


	Year Ended December 31,
(in millions)	2021		2020		2019
Derivatives designated as hedges:
Gain (loss) recognized in AOCI	$	147	$	(118)	$	76
Gain (loss) reclassified from AOCI into Product sales	$	(67)	$	47	$	127
Derivatives not designated as hedges:
Gain (loss) recognized in Other income (expense), net	$	21	$	(51)	$	22

From time to time, we may discontinue cash flow hedges and, as a result, record related amounts in Other income (expense), net on our Consolidated Statements of Income. There were no discontinuances of cash flow hedges for the years presented.

As of December 31, 2021 and 2020, we only held foreign currency exchange contracts. The following table summarizes the potential effect of offsetting our foreign currency exchange contracts on our Consolidated Balance Sheets:


							Gross Amounts Not Offset on the Consolidated Balance Sheets
(in millions)	Gross Amounts of Recognized Assets/Liabilities		Gross Amounts Offset on the Consolidated Balance Sheets		Amounts of Assets/Liabilities Presented on the Consolidated Balance Sheets		Derivative Financial Instruments		Cash Collateral Received/Pledged		Net Amount (Legal Offset)
As of December 31, 2021
Derivative assets	$	80	$	—	$	80	$	(4)	$	—	$	76
Derivative liabilities	$	5	$	—	$	5	$	(4)	$	—	$	1
As of December 31, 2020
Derivative assets	$	12	$	—	$	12	$	(12)	$	—	$	—
Derivative liabilities	$	121	$	—	$	121	$	(12)	$	—	$	109

Acquisitions

12 Months Ended

Dec. 31, 2021

Business Combination and Asset Acquisition [Abstract]

Acquisitions

ACQUISITIONS

MYR

In the first quarter of 2021, we completed the acquisition of MYR, a German biotechnology company. MYR focuses on the development and commercialization of therapeutics for the treatment of HDV. The acquisition provided Gilead with Hepcludex, which was conditionally approved by the European Medicines Agency (“EMA”) in July 2020 for the treatment of chronic HDV infection in adults with compensated liver disease. Upon closing, MYR became a wholly-owned subsidiary of Gilead. The financial results of MYR were included in our Consolidated Financial Statements from the date of the acquisition. Acquisition-related expenses were not material for the year ended December 31, 2021.

The aggregate consideration for this acquisition of €1.3 billion (or $1.6 billion) primarily consisted of €1.0 billion (or $1.2 billion) paid upon closing and contingent consideration of up to €300 million, subject to customary adjustments, representing a potential future milestone payment upon FDA approval of Hepcludex. The fair value of this contingent liability, estimated using probability-weighted scenarios for FDA approval, was $341 million as of the acquisition date and was initially recorded in Other long-term obligations on our Consolidated Balance Sheets. In the second quarter of 2021, the balance was reclassified to Accrued and other current liabilities on our Consolidated Balance Sheets. The estimated fair value of this contingent liability was $317 million as of December 31, 2021. The change in estimated fair value from the acquisition date was primarily due to the effect of foreign exchange remeasurement.

The acquisition of MYR was accounted for as a business combination using the acquisition method of accounting. This method requires, among other things, that assets acquired and liabilities assumed be generally recognized at fair value as of the acquisition date. The fair value estimates for the assets acquired and liabilities assumed were based upon valuations using information known and knowable as of the date of this filing. Changes to these assumptions and estimates could cause an impact to the valuation of assets acquired, including intangible assets, goodwill and the related tax impacts of the acquisition, as well as legal and other contingencies. The amounts recognized will be finalized as the information necessary to complete the analysis is obtained, but no later than one year after the acquisition date.

The following table summarizes estimated fair values of assets acquired and liabilities assumed as of the acquisition date:


(in millions)	Amount
Intangible assets:
Finite-lived intangible asset	$	845
Acquired IPR&D	1,190
Deferred income taxes, net	(513)
Other assets (and liabilities), net	(187)
Total identifiable net assets	1,335
Goodwill	226
Total consideration	$	1,561

Intangible Assets

The finite-lived intangible asset of $845 million represents the estimated fair value of Hepcludex for HDV in Europe as of the acquisition date. The fair value was determined by applying the income approach using unobservable inputs to estimate probability-weighted net cash flows attributable to Hepcludex for HDV in Europe and a discount rate of 12%. The discount rate used represents the estimated rate that market participants would use to value this intangible asset. This intangible asset is being amortized over an estimated useful life of 10 years.

Acquired IPR&D consists of Hepcludex for HDV in all other regions without regulatory approval, including the United States. The estimated aggregate fair value of $1.19 billion as of the acquisition date was determined by applying the income approach using unobservable inputs to estimate probability-weighted net cash flows attributable to this asset and a discount rate of 12%. The discount rate used represents the estimated rate that market participants would use to value this intangible asset.

Some of the more significant assumptions inherent in the development of intangible asset fair values include: estimates of projected future cash flows, including revenues and operating profits; probability of success; the discount rate selected; the life of the potential commercialized products and the risks related to the viability of and potential alternative treatments in any future target markets, among other factors.

The inputs used for valuing these identifiable intangibles are unobservable and considered Level 3 under the fair value measurement and disclosure guidance. See Note 3. Fair Value Measurements for additional information.

Deferred Income Taxes

The net deferred tax liability was based upon the difference between the estimated financial statement basis and tax basis of net assets acquired and an estimate for the final pre-acquisition net operating losses of MYR.

Goodwill

The excess of the consideration transferred over the fair values of assets acquired and liabilities assumed of $226 million was recorded as goodwill, which primarily reflects the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Goodwill recognized for MYR is not expected to be deductible for income tax purposes.

There were no material measurement period adjustments recorded to the fair values of assets acquired and liabilities assumed during the year ended December 31, 2021.

Immunomedics

In the fourth quarter of 2020, we completed the acquisition of Immunomedics, a company focused on the development of antibody-drug conjugate technology, for cash consideration of $20.6 billion. Upon closing, Immunomedics became a wholly-owned subsidiary of Gilead. The acquisition was financed with the majority of the proceeds from the September 2020 senior unsecured notes offering, an additional $1.0 billion borrowing under a new senior unsecured term loan facility and cash on hand. In 2021, we repaid the borrowing under the senior unsecured term loan facility. See Note 12. Debt and Credit Facilities for additional information.

We recorded share-based compensation expense of $289 million related to the cash settlement of the accelerated share-based compensation expense attributable to the post-combination period, which was primarily recorded in Selling, general and administrative expenses and Research and development expenses on our Consolidated Statements of Income for the year ended December 31, 2020. We also recorded other acquisition-related expenses of $39 million, primarily representing closing costs and related fees, in Selling, general and administrative expenses on our Consolidated Statements of Income for the year ended December 31, 2020.

The acquisition of Immunomedics was accounted for as a business combination using the acquisition method of accounting. This method requires, among other things, that assets acquired and liabilities assumed be generally recognized at fair value as of the acquisition date. There were no material measurement period adjustments recorded to the fair values of assets acquired and liabilities assumed during the year ended December 31, 2021. The fair value estimates for the assets acquired and liabilities assumed have been completed.

The following table summarizes fair values of assets acquired and liabilities assumed as of the acquisition date:


(in millions)	Amount
Cash and cash equivalents	$	726
Inventories	946
Intangible assets:
Finite-lived intangible asset	4,600
Acquired IPR&D	15,760
Outlicense contract	175
Deferred tax liabilities	(4,565)
Liability related to future royalties	(1,100)
Other assets (and liabilities), net	64
Total identifiable net assets	16,606
Goodwill	3,991
Total consideration transferred	$	20,597

Inventories

The fair value step-up adjustment of $881 million, included in inventories of $946 million as of the acquisition date, was primarily determined by the estimated selling price of finished inventory less the cost to complete the manufacturing process and selling effort. The step-up adjustment is recorded in Cost of goods sold on our Consolidated Statements of Income as the inventory is sold to customers and in Research and development expenses on our Consolidated Statements of Income for inventory used for clinical purposes.

Intangible Assets

The finite-lived intangible asset of $4.6 billion represents the estimated fair value of Trodelvy for metastatic triple-negative breast cancer (“TNBC”) as of the acquisition date. The fair value was determined by applying the income approach using unobservable inputs to estimate probability-weighted net cash flows attributable to Trodelvy for metastatic TNBC and a discount rate of 7.0%. The discount rate used represents the estimated rate that market participants would use to value this intangible asset. This intangible asset is being amortized over an estimated useful life of 12 years.

Acquired IPR&D assets consist of Trodelvy for hormone receptor positive, human epidermal growth factor receptor 2 negative, metastatic breast cancer, Trodelvy for non-small cell lung cancer and Trodelvy for urothelial cancer (“UC”). The estimated aggregate fair value of $15.8 billion as of the acquisition date was determined by applying the income approach using unobservable inputs to estimate probability-weighted net cash flows attributable to these assets and a discount rate of 7.0%. The discount rate used represents the estimated rate that market participants would use to value these intangible assets. Trodelvy for UC was granted accelerated approval by FDA in April 2021 and $1.0 billion was reclassified to finite-lived intangibles from IPR&D. See Note 9. Goodwill and Intangible Assets for additional information.

Some of the more significant assumptions inherent in the development of intangible asset fair values include: the amount and timing of projected future cash flows (including revenue, cost of sales, research and development costs, and sales and marketing expenses); probability of success; the discount rate selected to measure the inherent risk of future cash flows; the assessment of the asset’s life cycle and the competitive trends impacting the asset, among other factors.

We also recorded an intangible asset related to a license and supply agreement with a third party, which was entered into by Immunomedics prior to the acquisition. Under the agreement, the third party was granted an exclusive license to develop and commercialize Trodelvy in certain territories in Asia and make certain sales milestones and royalty payments to us. The acquisition date fair value of $175 million was determined by estimating the probability-weighted net cash flows attributable to the outlicense and a discount rate of 7.0%. The discount rate represents the estimated rate that market participants would use to value this intangible asset. This intangible asset is being amortized over an estimated useful life of 15 years on a straight-line basis.

The inputs used for valuing these identifiable intangibles are unobservable and considered Level 3 under the fair value measurement and disclosure guidance.

Deferred Income Taxes

The net deferred tax liability was based upon the difference between the estimated financial statement basis and tax basis of net assets acquired and an estimate for the final pre-acquisition net operating losses of Immunomedics.

Liability Related to Future Royalties

We assumed a liability related to a funding arrangement, which was originally entered into by Immunomedics and RPI Finance Trust (“RPI”), prior to our acquisition of Immunomedics. Under the funding agreement, RPI has the right to receive certain royalty amounts, subject to certain reductions, based on the net sales of Trodelvy for each calendar quarter during the term of the agreement through approximately 2036. The acquisition date fair value of the liability was estimated as $1.1 billion, which was primarily determined based on current estimates of future royalty payments to RPI over the life of the arrangement using the real options method and an effective annual interest rate of 2.5%. The liability is amortized using the effective interest rate method, resulting in recognition of interest expense over 16 years. The estimated timing and amount of future expected royalty payments over the estimated term will be re-assessed each reporting period. The impact from changes in estimates will be recognized in the liability and the related interest expense prospectively. The inputs used for valuation of this liability are unobservable and are considered Level 3 under the fair value measurement and disclosure guidance. See Note 3. Fair Value Measurements for additional information. The liability related to future royalties was categorized as debt and primarily included in Long-term debt, net on our Consolidated Balance Sheets. See Note 12. Debt and Credit Facilities for additional information.

Goodwill

The excess of the consideration transferred over the fair values of assets acquired and liabilities assumed of $4.0 billion was recorded as goodwill, which primarily reflects the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Goodwill recognized for Immunomedics is not expected to be deductible for income tax purposes.

Forty Seven, Inc. (“Forty Seven”)

In the second quarter of 2020, we completed the acquisition of Forty Seven, a clinical-stage immuno-oncology company focused on developing therapies targeting cancer immune evasion pathways and specific cell targeting approaches, for total consideration of $4.7 billion, net of acquired cash. Upon closing, Forty Seven became a wholly-owned subsidiary of Gilead. We accounted for the transaction as an asset acquisition since the lead asset, magrolimab, represented substantially all the fair value of the gross assets acquired. During the year ended December 31, 2020, we recorded a $4.5 billion charge representing an acquired IPR&D asset with no alternative future use in Acquired in-process research and development expenses, and stock-based compensation expense of $144 million primarily in Research and development expenses on our Consolidated Statements of Income.

Inventories

12 Months Ended

Dec. 31, 2021

Inventory Disclosure [Abstract]

Inventories

INVENTORIES

The following table summarizes our Inventories:


	December 31,
(in millions)	2021		2020
Raw materials	$	1,112	$	1,080
Work in process	590		976
Finished goods	1,032		958
Total	$	2,734	$	3,014

Reported as:
Inventories	$	1,618	$	1,683
Other long-term assets	1,116		1,331
Total	$	2,734	$	3,014

Amounts reported as Other long-term assets primarily consisted of raw materials as of December 31, 2021 and 2020. Total inventories as of December 31, 2021 and 2020 include $294 million and $797 million, respectively, of fair value adjustments resulting from the Immunomedics acquisition.

Inventory write-down charges were $228 million, $86 million and $649 million for the years ended December 31, 2021, 2020 and 2019, respectively. During the year ended December 31, 2019, $547 million of the $649 million inventory write-down charges was related to slow-moving and excess raw material and work in process inventory primarily due to lower long-term demand for our HCV products.

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

PROPERTY, PLANT AND EQUIPMENT

The following table summarizes our Property, plant and equipment, net:


	December 31,
(in millions)	2021		2020
Land and land improvements	$	404	$	404
Buildings and improvements (including leasehold improvements)	3,794		3,678
Laboratory and manufacturing equipment	952		904
Office, computer equipment and other	807		793
Construction in progress	1,057		856
Subtotal	7,014		6,635
Less: accumulated depreciation and amortization	1,893		1,668
Total	$	5,121	$	4,967

We had unamortized capitalized software costs, included in Office, computer equipment and other, of $131 million and $124 million as of December 31, 2021 and 2020, respectively. Capitalized interest on construction in progress is included in Property, plant and equipment, net on our Consolidated Balance Sheets. Interest capitalized in 2021 and 2020 was not material.

The net book value of our property, plant and equipment in the United States was $4.1 billion and $4.0 billion as of December 31, 2021 and 2020, respectively. The corresponding amount in international locations was $963 million and $940 million as of December 31, 2021 and 2020, respectively. All individual international locations accounted for less than 10% of the total balances.

Goodwill and Intangible Assets

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill and Intangible Assets

GOODWILL AND INTANGIBLE ASSETS

Goodwill

The following table summarizes the changes in the carrying amount of Goodwill:


	December 31,
(in millions)	2021		2020
Beginning balance	$	8,108	$	4,117
Goodwill resulting from acquisitions	226		3,991
Measurement period adjustments	(2)		—
Ending balance	$	8,332	$	8,108

We perform an annual goodwill impairment assessment in the fourth quarter or earlier if impairment indicators exist. As of December 31, 2021, there were no accumulated goodwill impairment losses.

Intangible Assets

The following table summarizes our Intangible assets, net:


	December 31, 2021								December 31, 2020
(in millions)	Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount
Finite-lived assets
Intangible asset - sofosbuvir	$	10,720	$	(5,651)	$	—	$	5,069	$	10,720	$	(4,952)	$	—	$	5,768
Intangible asset - axicabtagene ciloleucel(1)	7,110		(1,501)		—		5,609		6,200		(1,105)		—		5,095
Intangible asset - Trodelvy(2)	5,630		(507)		—		5,123		4,600		(63)		—		4,537
Intangible asset - Hepcludex	845		(72)		—		773		—		—		—		—
Other(3)	1,610		(650)		1		961		1,377		(540)		(1)		836
Total finite-lived assets	25,915		(8,381)		1		17,535		22,897		(6,660)		(1)		16,236
Indefinite-lived assets - IPR&D(4)	15,920		—		—		15,920		16,890		—		—		16,890
Total intangible assets	$	41,835	$	(8,381)	$	1	$	33,455	$	39,787	$	(6,660)	$	(1)	$	33,126

________________________________

(1) Gross carrying amount as of December 31, 2021 includes $910 million reclassified in the first quarter of 2021 from indefinite-lived assets - IPR&D following the March 2021 FDA approval of Yescarta for the treatment of adult patients with relapsed or refractory follicular lymphoma.

(2) Gross carrying amount as of December 31, 2021 includes Trodelvy for metastatic TNBC and Trodelvy for use in adult patients with locally advanced or metastatic UC. The amount related to UC of $1.0 billion was reclassified to finite-lived assets from indefinite-lived assets - IPR&D upon the accelerated approval by FDA in April 2021.

(3) In October 2021, FDA granted approval of Tecartus for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia. Accordingly, the related amount of $200 million was reclassified to finite-lived assets in the fourth quarter of 2021.

(4) Gross carrying amount as of December 31, 2021 includes IPR&D from our 2021 acquisition of MYR and remaining IPR&D from our 2020 acquisition of Immunomedics. Gross carrying amount as of December 31, 2020 includes IPR&D from our 2020 acquisition of Immunomedics and remaining IPR&D from our 2017 acquisition of Kite.

Aggregate amortization expense related to finite-lived intangible assets was $1.7 billion, $1.2 billion and $1.1 billion for the years ended December 31, 2021, 2020 and 2019, respectively, and is primarily included in Cost of goods sold on our Consolidated Statements of Income.

Amounts capitalized as IPR&D are subject to impairment testing until the completion or abandonment of the associated R&D efforts. During 2021, we performed a qualitative assessment of our IPR&D intangible asset obtained in connection with our first quarter 2021 acquisition of MYR and did not identify any indicators of impairment. During 2021, 2020 and 2019, we performed quantitative impairment testing of our IPR&D intangible assets, other than the MYR asset described above, using a probability-weighted income approach that discounts expected future cash flows to present value using discount rates of 6.5%, 8.0% and 9.5%, respectively. The discount rates are based on the estimated weighted-average cost of capital for companies with profiles similar to our profile and represents the rate that market participants would use to value the intangible assets. The discounted cash flow models used in valuing these intangible assets also require the use of Level 3 fair value measurements and inputs including estimated revenues, costs, and probability of technical and regulatory success. No IPR&D impairment charges were recorded in 2021 and 2020.

During 2019, we lowered our estimated revenues related to our IPR&D intangible asset - axicabtagene ciloleucel for the treatment of indolent B-cell non-Hodgkin lymphoma due to changes in the estimated market opportunities as new therapies or combinations of existing therapies were approved. The lower estimated revenues reduced the fair value of the IPR&D intangible assets below carrying value resulting in the recognition of an impairment charge of $800 million, which was recorded within Acquired in-process research and development expenses on our Consolidated Statements of Income.

The following table summarizes the estimated future amortization expense associated with our finite-lived intangible assets as of December 31, 2021:


(in millions)	Amount
2022	$	1,778
2023	1,778
2024	1,778
2025	1,773
2026	1,765
Thereafter	8,663
Total	$	17,535

Other Financial Information

12 Months Ended

Dec. 31, 2021

Other Financial Information [Abstract]

Other Financial Information

OTHER FINANCIAL INFORMATION

Accounts receivable, net

The following table summarizes our Accounts receivable, net:


	December 31,
(in millions)	2021		2020
Accounts receivable	$	5,278	$	5,560
Less: chargebacks	671		552
Less: cash discounts and other	67		72
Less: allowances for credit losses	47		44
Accounts receivable, net	$	4,493	$	4,892

Accrued and other current liabilities

The following table summarizes the components of Accrued and other current liabilities:


	December 31,
(in millions)	2021		2020
Compensation and employee benefits	$	927	$	864
Income taxes payable	539		598
Allowance for sales returns	499		587
Accrual for settlement related to bictegravir litigation(1)	1,250		—
Other accrued liabilities	2,930		2,287
Accrued and other current liabilities	$	6,145	$	4,336

_______________________________

(1) See Note 14. Commitments and Contingencies for additional information.

Collaborations and Other Arrangements	12 Months Ended
Collaborations and Other Arrangements	Dec. 31, 2021
Collaborative and Other Arrangements [Abstract]
Collaborations and Other Arrangements	COLLABORATIONS AND OTHER ARRANGEMENTS We enter into licensing and strategic collaborations and other similar arrangements with third parties for the development and commercialization of certain products and product candidates. These arrangements may involve two or more parties who are active participants in the operating activities of the collaboration and are exposed to significant risks and rewards depending on the commercial success of the activities. These arrangements may include non-refundable upfront payments, expense reimbursements or payments by us for options to acquire certain rights, contingent obligations by us for potential development and regulatory milestone payments and/or sales-based milestone payments, royalty payments, revenue or profit-sharing arrangements and cost-sharing arrangements. We also have equity investments in third parties focused on the development and commercialization of products and product candidates. Merck & Co, Inc. (“Merck”) On March 13, 2021, we entered into a license and collaboration agreement with Merck Sharp & Dohme Corp., a subsidiary of Merck to jointly develop and commercialize long-acting investigational treatments in HIV that combine Gilead’s investigational capsid inhibitor, lenacapavir, and Merck’s investigational nucleoside reverse transcriptase translocation inhibitor, islatravir. The collaboration will initially focus on long-acting oral and injectable formulations. Under the terms of the agreement, Gilead and Merck will share global development and commercialization costs at 60% and 40%, respectively, across the oral and injectable formulation programs. For long-acting oral products, if approved, Gilead would lead commercialization in the United States, and Merck would lead commercialization in the European Union (“EU”) and rest of the world. For long-acting injectable products, if approved, Merck would lead commercialization in the United States and Gilead would lead commercialization in the EU and rest of the world. Under the terms of the agreement, Gilead and Merck would jointly promote the combination products in the United States and certain other major markets. If successful, we would share global product revenues with Merck equally until product revenues surpass certain pre-determined per formulation revenue tiers. Upon passing $2.0 billion in net product sales for the oral combination in a given calendar year, our share of revenue would increase to 65% for any revenues above the threshold for such calendar year. Upon passing $3.5 billion in net product sales for the injectable combination in a given calendar year, our share of revenue will increase to 65% for any revenues above the threshold for such calendar year. Reimbursements of research and development costs to or from Merck are recorded within Research and development expenses on our Consolidated Statements of Income. Expenses recognized under the agreement were not material for the year ended December 31, 2021. No revenues have been recognized under the agreement for the year ended December 31, 2021. We will also have the option to license certain of Merck’s investigational oral integrase inhibitors to develop in combination with lenacapavir. Reciprocally, Merck will have the option to license certain of Gilead’s investigational oral integrase inhibitors to develop in combination with islatravir. Each company may exercise its option for such investigational oral integrase inhibitor of the other company within the first five years after execution of the agreement, following completion of the first Phase 1 clinical trial of that integrase inhibitor. Upon exercise of an option, the companies will split development costs and revenues, unless the non-exercising company decides to opt-out, in which case the non-exercising company will be paid a royalty. In December 2021, Merck announced the decision of the parties to stop all dosing of participants in the Phase 2 clinical study evaluating an oral-weekly combination treatment regimen of lenacapavir and islatravir following the decision of FDA to place clinical holds on the investigational new drug applications for certain formulations of islatravir. Arcus On May 27, 2020, we entered into a transaction with Arcus, a publicly traded oncology-focused biopharmaceutical company, which included entry into an option, license and collaboration agreement (the “Collaboration Agreement”) and a common stock purchase agreement and an investor rights agreement (together, and as subsequently amended the “Stock Purchase Agreements”). In accordance with the terms of the Collaboration Agreement and Stock Purchase Agreements, which closed on July 13, 2020, we made an upfront payment of $175 million and acquired approximately 6.0 million shares of Arcus common stock for approximately $200 million. Of the total $391 million initial cash payments, including transactional costs, made under the agreements, we recorded $135 million as an equity investment which was calculated based on Arcus’ closing stock price on the closing date of the transaction. The remaining $256 million was attributed to (i) the acquired license and option rights of $175 million representing IPR&D assets with no alternative future use, (ii) $65 million of an issuance premium for the equity purchase and (iii) $16 million of direct transactional costs. These amounts were expensed as Acquired in-process research and development expenses during the year ended December 31, 2020 on our Consolidated Statements of Income. Under the Stock Purchase Agreements, we have the right to purchase additional shares of Arcus from Arcus over the five-year period beginning on the closing of the Stock Purchase Agreements, up to a maximum of 35% of the outstanding voting stock. We are subject to a three-year standstill, restricting our ability to acquire voting stock of Arcus exceeding more than 35% of the then-issued and outstanding voting stock of Arcus, subject to certain exceptions. Additionally, we agreed not to dispose of any equity securities of Arcus prior to the second anniversary of the closing of the Stock Purchase Agreements without the prior consent of Arcus, subject to certain exceptions. On May 29, 2020, in a separate secondary equity offering, we acquired 2.2 million shares of common stock of Arcus for approximately $61 million. In the first quarter of 2021, we also acquired approximately 5.7 million additional shares of Arcus common stock for $220 million. As a result, we currently own a total of 13.8 million shares of Arcus, which represented approximately 19.5% of the issued and outstanding voting stock of Arcus immediately following the closing of the first quarter 2021 transaction. Pursuant to the Collaboration Agreement, Gilead had the right to opt in to all current and future clinical-stage product candidates for up to ten years following the closing of the transaction. In November 2021, we exercised our options to three of Arcus’ clinical stage programs and amended the Collaboration Agreement. The option exercise and amendment transaction closed in December 2021, triggering collaboration opt-in payments of $725 million and waiving the $100 million option continuation payment which would have been due to Arcus in the third quarter of 2022. The net option charge of $625 million was recorded within Research and development expenses on our Consolidated Statements of Income for the year ended December 31, 2021. The collaboration opt-in payments of $725 million were recorded in Accrued and other current liabilities on our Consolidated Balance Sheets as of December 31, 2021 and paid to Arcus in January 2022. Our payments to Arcus will be included within Net cash provided by investing activities on our Consolidated Statements of Cash Flows in the first quarter of 2022. Under the amended Collaboration Agreement, the companies will co-develop and share the global costs related to these clinical programs. If the optioned molecules achieve regulatory approval, the companies will co-commercialize and equally share profits in the U.S. Gilead will hold exclusive commercialization rights outside the U.S., subject to any rights of Arcus’s existing collaboration partners, and will pay to Arcus tiered royalties as a percentage of net sales ranging from the mid-teens and low twenties. Under the Collaboration Agreement, we may also pay an additional $100 million at our option on each of the fourth, sixth and eighth anniversaries of the agreement, unless terminated early, to maintain the rights to opt-in to future Arcus programs for the duration of the contact term. We elected and applied the fair value option to account for our equity investment in Arcus whereby the investment is marked to market each reporting period based on the market price of Arcus shares. We believe the fair value option best reflects the underlying economics of the investment. During the years ended December 31, 2021 and 2020, we recorded pre-tax unrealized gains of $127 million and $80 million, respectively, related to our investment in Arcus in Other income (expense), net on our Consolidated Statements of Income. We initially recorded our equity investments in Arcus in Other long-term assets on our Consolidated Balance Sheets as the investments were subject to contractual lock-up provisions for a period of two years from the closing date of the Stock Purchase Agreements, subject to certain conditions. In the third quarter of 2021, we reclassified our equity investments in Arcus to Prepaid and other current assets on our Consolidated Balance Sheets as the contractual lock-up provisions are expected to expire in July 2022. Our equity investment in Arcus was $559 million and $212 million as of December 31, 2021 and 2020, respectively. Pionyr On June 19, 2020, we entered into a transaction with Pionyr, a privately held company pursuing novel biology in the field of immuno-oncology, which included entry into two separate merger agreements, one contemplating the initial acquisition of a 49.9% equity interest in Pionyr, and the other providing us the exclusive option, subject to certain terms and conditions, to acquire the remaining outstanding capital stock of Pionyr (together, the “Pionyr Merger and Option Agreements”) and a research and development service agreement. On July 13, 2020, we closed the transaction and made cash payments of $269 million. We account for our investment in Pionyr using the equity method of accounting because our equity interest provides us with the ability to exercise significant influence over Pionyr. Our investment in Pionyr, consisting of the transaction price noted above and transaction costs, exceeded our pro-rata portion of Pionyr's net assets at transaction closing. We determined that the resulting basis difference primarily relates to Pionyr’s IPR&D which has no alternative future use and that Pionyr is not a business as defined in ASC 805, “Business Combinations.” As a result, we immediately recorded a charge for this basis difference of $215 million in Acquired in-process research and development expenses on our Consolidated Statements of Income during the year ended December 31, 2020. The carrying value of our equity method investment in Pionyr was zero as of December 31, 2021 and 2020. The estimated fair value of our exclusive option to acquire the remaining outstanding capital stock of Pionyr is approximately $70 million based on a probability-weighted option pricing model using unobservable inputs, which are considered Level 3 under the fair value measurement and disclosure guidance. The estimated amount is recorded in Other long-term assets on our Consolidated Balance Sheets. We may choose to exercise our exclusive option to purchase the remaining equity interest from Pionyr’s current shareholders for a $315 million option exercise fee and up to $1.2 billion in potential future milestone payments upon achievement of certain development and regulatory milestones. Such option to purchase will expire following the earliest occurrence of specified events, including the delivery of data following completion of certain Phase 1b trials by Pionyr. Under the research and development service agreement, we made an initial cash funding of $80 million and recorded a charge in Acquired in-process research and development expenses on our Consolidated Statements of Income during the year ended December 31, 2020. In addition, we committed to provide additional payments of up to $115 million to Pionyr upon achievement of certain development milestones. We accrued $70 million in milestone payments, related to the initiation of two Phase 1 studies, with a charge to Research and development expenses on our Consolidated Statements of Income during the year ended December 31, 2020, and the payment was made in the first quarter of 2021. Tizona On July 17, 2020, we entered into a transaction with Tizona, a privately held company developing cancer immunotherapies, which included entry into two separate merger agreements, one contemplating the initial acquisition of a 49.9% equity interest in Tizona, and the other providing us the exclusive option, subject to certain terms and conditions, to acquire the remaining outstanding capital stock of Tizona (together, the “Tizona Merger and Option Agreements”) and a development agreement. On August 25, 2020, we closed the transaction with Tizona and made cash payments of $302 million to Tizona’s shareholders in accordance with the terms of the Tizona Merger and Option Agreements. We account for our investment in Tizona using the equity method of accounting because our equity interest provides us with the ability to exercise significant influence over Tizona. Our investment in Tizona, consisting of the transaction price noted above and transaction costs, exceeded our pro-rata portion of Tizona’s net assets at transaction closing. We determined that the resulting basis difference primarily relates to Tizona’s IPR&D with no alternative future use and that Tizona is not a business as defined in ASC 805, “Business Combinations.” As a result, during the year ended December 31, 2020, we immediately recorded a charge for this basis difference of $272 million in Acquired in-process research and development expenses on our Consolidated Statements of Income. The carrying value of our equity method investment in Tizona was zero as of December 31, 2021 and 2020. The estimated fair value of our exclusive option to acquire the remaining outstanding capital stock of Tizona is approximately $41 million based on a probability-weighted option pricing model using unobservable inputs, which are considered Level 3 under the fair value measurement and disclosure guidance. The estimated amount is recorded in Other long-term assets on our Consolidated Balance Sheets. We may choose to exercise our exclusive option to purchase the remaining equity interest from Tizona’s current shareholders for a $100 million option exercise fee and up to $1.2 billion in potential future milestone payments upon achievement of certain development and regulatory milestones. Such option to purchase will expire following the earliest occurrence of specified events, including the delivery of data following completion of certain Phase 1b trials by Tizona. Under the development agreement, we committed to provide funding to Tizona of $115 million, which was recorded in Acquired in-process research and development expenses on our Consolidated Statements of Income during the year ended December 31, 2020. Tango Therapeutics, Inc. (“Tango”) On August 17, 2020, we entered into a transaction with Tango, a privately held company pursuing innovative targeted immune evasion therapies for patients with cancer through its proprietary, CRISPR-enabled functional genomics target discovery platform, which included entry into an amended and restated research collaboration and license agreement and a stock purchase agreement (together, the “Tango Collaboration and Stock Purchase Agreements”). Upon entering into this transaction, we made an upfront payment of $125 million and a $20 million equity investment in Tango. During the year ended December 31, 2020, we recorded the $125 million upfront expense in Acquired in-process research and development expenses on our Consolidated Statements of Income. In the third quarter of 2021, we made an additional $13 million equity investment. Tango became a publicly traded company in the third quarter of 2021, and accordingly our equity investment is recorded in Prepaid and other current assets on our Consolidated Balance Sheets at fair market value as of December 31, 2021. Under the Tango Collaboration and Stock Purchase Agreements, Gilead has the right to option up to 15 programs over the seven-year collaboration for up to $410 million per program in opt-in, extension and milestone payments. For the products that Tango opts to co-develop and co-promote, the parties will equally split profits and losses, as well as development costs in the U.S. For products that Tango does not opt to co-develop and co-promote, we will pay Tango up to low double-digit tiered royalties on net sales. We will provide Tango milestone payments and royalties on sales outside of the U.S. Jounce Therapeutics, Inc. (“Jounce”) On September 1, 2020, we entered into a transaction with Jounce, a publicly traded company developing novel cancer immunotherapies, which included entry into license, registration rights and stock purchase agreements (together, “Jounce License and Stock Purchase Agreement”). In October 2020, we closed this transaction and made a total payment of $120 million. We recorded $64 million upfront expense in Acquired in-process research and development expenses on our Consolidated Statements of Income and $56 million as an equity investment in Other long-term assets on our Consolidated Balance Sheets, representing approximately 14% of the issued and outstanding voting stock of Jounce immediately following the transaction, which was calculated based on Jounce’s closing stock price on the closing date of the transaction. As of December 31, 2021, Jounce was eligible to receive from us up to $660 million in future potential clinical, regulatory and commercial milestone payments upon achievement of certain milestones, and royalties ranging from high single digit to mid-teens based upon worldwide sales, subject to certain adjustments. Galapagos Filgotinib Collaboration In 2016, we closed a license and collaboration agreement with Galapagos, a clinical-stage biotechnology company based in Belgium, for the development and commercialization of filgotinib, a JAK1-selective inhibitor being evaluated for inflammatory disease indications (the “filgotinib agreement”). Upon closing, we made an upfront license fee payment and an equity investment in Galapagos by subscribing for 6.8 million new ordinary shares of Galapagos at a price of €58 per share. We amended the terms of the agreement in 2019, 2020 and 2021. Under the terms of the filgotinib agreement, as amended in 2019 (the “2019 Agreement”), we obtained an exclusive, worldwide, royalty-bearing, sublicensable license for filgotinib and products containing filgotinib. In December 2020, following a Type A meeting with FDA to discuss the points raised in the Complete Response Letter related to the New Drug Application for filgotinib in the treatment of rheumatoid arthritis, Gilead and Galapagos agreed to amend the 2019 Agreement to allow Galapagos to assume development, manufacturing, commercialization and certain other rights for filgotinib in Europe which the parties reflected in an amendment to the 2019 Agreement in December 2021. Beginning on January 1, 2021, Galapagos bore the development costs for certain studies, in lieu of the equal cost split contemplated by the 2019 Agreement. The parties transferred filgotinib’s marketing authorizations in the EU and Great Britain to Galapagos in December 2021. As of January 1, 2022, all commercial economics on filgotinib in Europe transferred to Galapagos, subject to payment of tiered royalties of 8% to 15% of net sales in Europe to Gilead, starting in 2024. In connection with the amendments to the 2019 Agreement, Gilead agreed to irrevocably pay Galapagos €160 million (or approximately $190 million), which is subject to certain adjustments for higher-than-budgeted development costs. Of this total amount, Gilead paid €35 million (or approximately $43 million) in January 2021 and paid an additional €75 million (or approximately $88 million) in April 2021 and will pay €50 million (or approximately $60 million) in 2022. We accrued the full amount of this liability with a charge to Research and development expenses on our Consolidated Statements of Income for the year ended December 31, 2020. In addition, Galapagos will no longer be eligible to receive any future milestone payments relating to filgotinib in Europe. Global Collaboration In August 2019, we closed an option, license and collaboration Agreement (the “Galapagos Collaboration Agreement”) and a subscription agreement (the “Galapagos Subscription Agreement”), each with Galapagos, pursuant to which the parties entered into a global collaboration that covers Galapagos’ current and future product portfolio (other than filgotinib). Upon closing, we paid $5.05 billion for the license and option rights and for 6.8 million new ordinary shares of Galapagos at a subscription price of €140.59 per share with a fair value of $1.13 billion, which included an issuance discount of $63 million calculated based on Galapagos’ closing stock price on the date of closing of the Galapagos Subscription Agreement. The remaining $3.92 billion of the payment was recorded within Acquired in-process research and development expenses on our Consolidated Statements of Income for the year ended December 31, 2019. Pursuant to the Galapagos Subscription Agreement, we were issued warrants that confer the right to subscribe, from time to time, for a number of new shares to be issued by Galapagos sufficient to bring the number of shares owned by us to 29.9% of the issued and outstanding shares at the time of our exercises. In 2019, we exercised a warrant to subscribe for 2.6 million ordinary shares of Galapagos at €140.59 per share and purchased shares on the open market with an aggregate fair value of $586 million, which brought the number of shares owned by us to 16.7 million or approximately 25.8% of the shares then issued and outstanding. We are subject to a 10-year standstill restricting our ability to acquire voting securities of Galapagos exceeding more than 29.9% of the then-issued and outstanding voting securities of Galapagos. We agreed not to, without the prior consent of Galapagos, dispose of any equity securities of Galapagos prior to the second anniversary of the closing of the Galapagos Subscription Agreement or dispose of any equity securities of Galapagos thereafter until the fifth anniversary of the closing of the Galapagos Subscription Agreement, if after such disposal we would own less than 20.1% of the then-issued and outstanding voting securities of Galapagos, subject to certain exceptions and termination events. In April 2021, we amended the Galapagos Subscription Agreement to extend the initial lock-up provision for certain Galapagos shares from August 2021 to August 2024. We have two designees appointed to Galapagos’ board of directors. The initial contractual lock-up provision for certain Galapagos shares was due to expire in August 2021. As such, $351 million was included within Prepaid and other current assets on our Consolidated Balance Sheets and the remainder of $1.3 billion was included within Other long-term assets on our Consolidated Balance Sheets as of December 31, 2020. Subsequent to the extension of the contractual lock-up period, all of our equity investment in Galapagos was classified to Other long-term assets on our Consolidated Balance Sheets, and was $931 million as of December 31, 2021. We have elected the fair value option to account for our equity investment in Galapagos whereby the investment is marked to market through earnings each reporting period based on the market price of Galapagos’ shares. We believe the fair value option best reflects the underlying economics of the investment. During the years ended December 31, 2021, 2020 and 2019, we recorded pre-tax unrealized losses of $717 million and $1.8 billion and a pre-tax unrealized gain of $1.2 billion, respectively, related to our investment in Galapagos in Other income (expense), net on our Consolidated Statements of Income due to changes in Galapagos’ stock price. Under the Galapagos Collaboration Agreement, we had an exclusive license for the development and commercialization of GLPG-1690, a late-stage candidate for idiopathic pulmonary fibrosis, in our territories and had an option to participate in the development and commercialization of Galapagos’ other current and future clinical programs that have entered clinical development during the first ten years of the collaboration, subject to extension in certain circumstances. Gilead and Galapagos terminated the Phase 3 clinical studies with GLPG-1690 in February 2021. With respect to all other programs in Galapagos’ current and future pipeline, if we exercise our option to a program, we will pay a $150 million option exercise fee per program. In addition, Galapagos will receive tiered royalties ranging from 20% to 24% on net sales in our territories of each Galapagos product optioned by us. If we exercise our option for a program, the parties will share equally in development costs and mutually agreed commercialization costs incurred subsequent to our exercise of the option. We may terminate the collaboration in its entirety or on a program-by-program and country-by-country basis with advance notice as well as following other customary termination events. Janssen Complera/Eviplera and Odefsey In 2009, we entered into a license and collaboration agreement with Janssen, formerly Tibotec Pharmaceuticals, to develop and commercialize a fixed-dose combination of our Truvada and Janssen’s non-nucleoside reverse transcriptase inhibitor, rilpivirine. This combination was approved in the U.S. and EU in 2011 and is sold under the brand name Complera in the U.S. and Eviplera in the EU. The agreement was amended in 2014 to expand the collaboration to include another product containing Janssen’s rilpivirine and our emtricitabine and tenofovir alafenamide (“Odefsey”). Under the amended agreement, Janssen granted us an exclusive license to Complera/Eviplera and Odefsey worldwide, but retained rights to distribute both combination products in certain countries outside of the U.S. Neither party is restricted from combining its drugs with any other drug products except those which are similar to the components of Complera/Eviplera and Odefsey. We are responsible for manufacturing Complera/Eviplera and Odefsey and have the lead role in registration, distribution and commercialization of both products except in the countries where Janssen distributes. Janssen has exercised a right to co-detail the combination product in some of the countries where we are the selling party. Under the financial provisions of the 2014 amendment, the selling party sets the price of the combined products and the parties share revenues based on the ratio of the net selling prices of the party’s component(s), subject to certain restrictions and adjustments. We retain a specified percentage of Janssen’s share of revenues, including up to 30% in major markets. Sales of these products are included in Product sales and Janssen’s share of revenues is included in Cost of goods sold on our Consolidated Statements of Income. Cost of goods sold relating to Janssen’s share was $530 million, $570 million and $574 million for the years ended December 31, 2021, 2020 and 2019, respectively. Termination of the agreement may be on a product or country basis and will depend on the circumstances, including withdrawal of a product from the market, material breach by either party or expiry of the revenue share payment term. We may terminate the agreement without cause with respect to the countries where we sell the products, in which case Janssen has the right to become the selling party for such country if the product has launched but has been on the market for fewer than 10 years. Symtuza In 2014, we amended a license and collaboration agreement with Janssen to develop and commercialize a fixed-dose combination of Janssen’s darunavir and our cobicistat, emtricitabine and tenofovir alafenamide (“Gilead Compounds”). This combination was approved in the U.S. and EU in July 2018 and September 2017, respectively, and is sold under the brand name Symtuza. Under the terms of the 2014 amendment, we granted Janssen an exclusive license to Symtuza worldwide. Janssen is responsible for manufacturing, registration, distribution and commercialization of Symtuza worldwide. We are responsible for the intellectual property related to the Gilead Compounds and are the exclusive supplier of the Gilead Compounds. Neither party is restricted from combining its drugs with any other drug products except those which are similar to the components of Symtuza. Janssen sets the price of Symtuza and the parties share revenue based on the ratio of the net selling prices of the party’s component(s), subject to certain restrictions and adjustments. The intellectual property license and supply obligations related to the Gilead Compounds are accounted for as a single performance obligation. As the license was deemed to be the predominant item to which the revenue share relates, we recognize our share of the Symtuza revenue in the period when the corresponding sales of Symtuza by Janssen occur. We record our share of the Symtuza revenue as Product sales on our Consolidated Statements of Income primarily because we supply the Gilead Compounds to Janssen for Symtuza. Termination of the agreement may be on a product or country basis and will depend on the circumstances, including withdrawal of a product from the market, material breach by either party or expiry of the revenue share payment term. Janssen may terminate the agreement without cause on a country-by-country basis, in which case Gilead has the right to become the selling party for such country(ies) if the product has launched but has been on the market for fewer than 10 years. Janssen may also terminate the entire agreement without cause. Japan Tobacco, Inc. (“Japan Tobacco”) In 2005, Japan Tobacco granted us exclusive rights to develop and commercialize elvitegravir, a novel HIV integrase inhibitor, in all countries of the world, excluding Japan, where Japan Tobacco retained such rights. Effective December 2018, we entered into an agreement with Japan Tobacco to acquire the rights to market and distribute certain products in our HIV portfolio in Japan and to expand our rights to develop and commercialize elvitegravir to include Japan. We are responsible for the marketing of the products as of January 1, 2019. We are responsible for seeking regulatory approval in our territories and are required to use diligent efforts to commercialize elvitegravir for the treatment of HIV infection. We bear all costs and expenses associated with such commercialization efforts and pay a royalty to Japan Tobacco based on our product sales. Our sales of these products are included in Product sales on our Consolidated Statements of Income. Royalties due to Japan Tobacco are included in Cost of goods sold on our Consolidated Statements of Income. Royalty expenses recognized were $250 million, $291 million and $358 million for the years ended December 31, 2021, 2020 and 2019, respectively. Under the terms of the 2018 agreement, we paid Japan Tobacco $559 million in cash and recognized an intangible asset of $550 million reflecting the estimated fair value of the marketing-related rights acquired from Japan Tobacco. The intangible asset is being amortized over nine years, representing the period over which the majority of the benefits are expected to be derived from the applicable products in our HIV portfolio. The amortization expense is classified as selling expense and recorded as Selling, general and administrative expenses on our Consolidated Statements of Income. Termination of the agreement may be on a product or country basis and will depend on the circumstances, including material breach by either party or expiry of royalty payment term. We may also terminate the entire agreement without cause. Gadeta B.V. (“Gadeta”) In July 2018, we entered into a collaboration arrangement with Gadeta and made a purchase of equity in Gadeta from Gadeta’s shareholders. We determined that Gadeta was a VIE, and we were its primary beneficiary because we had the power to direct the activities of Gadeta that most significantly impact its economic performance. Upon the initial consolidation of Gadeta, we recorded $82 million to Noncontrolling interest, primarily reflecting acquired intangible assets related to IPR&D, on our Consolidated Balance Sheets. During the year ended December 31, 2020, we effectively terminated the agreement with Gadeta. Upon the effective termination, we ceased to have a controlling interest and deconsolidated this VIE by removing the related net assets and noncontrolling interest of $82 million from our Consolidated Balance Sheets. The net loss from the deconsolidation was not material. Other Collaboration Arrangements That Are Not Individually Significant During 2021, 2020 and 2019, we entered into several collaborations, equity investments and licensing arrangements as well as other similar arrangements that we do not consider to be individually material. We recorded upfront collaboration expenses related to these arrangements of $177 million, $129 million and $331 million for the years ended December 31, 2021, 2020 and 2019, respectively, within Acquired in-process research and development expenses on our Consolidated Statements of Income. Cash payments for our equity investments, other than those noted above, during the years ended December 31, 2021, 2020 and 2019 were $147 million, $72 million and $118 million, respectively, which were primarily recorded within Prepaid and other current assets and Other long-term assets on our Consolidated Balance Sheets. Under the financial terms of these arrangements, we may be required to make payments upon achievement of various developmental, regulatory and commercial milestones, which could be significant. Future milestone payments, if any, will be reflected in our Consolidated Statements of Income when the corresponding events become probable. In connection with the regulatory approvals, milestone payments made will be capitalized as intangible assets and will be amortized to Cost of goods sold through the terms of these collaboration arrangements. In addition, we may be required to pay significant royalties on future sales if products related to these arrangements are commercialized. The payment of these amounts, however, is contingent upon the occurrence of various future events, which have a high degree of uncertainty.

Debt and Credit Facilities

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Debt and Credit Facilities

DEBT AND CREDIT FACILITIES

The following table summarizes the carrying amount of our borrowings under various financing arrangements:


(in millions)				December 31,
Type of Borrowing	Issue Date	Due Date	Interest Rate	2021		2020
Senior Unsecured	March 2011	April 2021	4.50%	$	—	$	1,000
Senior Unsecured	September 2020	September 2021	3-month LIBOR + 0.15%	—		499
Senior Unsecured	December 2011	December 2021	4.40%	—		1,249
Senior Unsecured	September 2016	March 2022	1.95%	500		499
Senior Unsecured	September 2015	September 2022	3.25%	999		998
Senior Unsecured	September 2016	September 2023	2.50%	748		748
Senior Unsecured	September 2020	September 2023	3-month LIBOR + 0.52%	—		498
Senior Unsecured	September 2020	September 2023	0.75%	1,496		1,992
Term Loan	October 2020	October 2023	variable	—		998
Senior Unsecured	March 2014	April 2024	3.70%	1,747		1,746
Senior Unsecured	November 2014	February 2025	3.50%	1,747		1,746
Senior Unsecured	September 2015	March 2026	3.65%	2,739		2,737
Senior Unsecured	September 2016	March 2027	2.95%	1,247		1,246
Senior Unsecured	September 2020	October 2027	1.20%	746		745
Senior Unsecured	September 2020	October 2030	1.65%	993		992
Senior Unsecured	September 2015	September 2035	4.60%	992		991
Senior Unsecured	September 2016	September 2036	4.00%	742		741
Senior Unsecured	September 2020	October 2040	2.60%	987		986
Senior Unsecured	December 2011	December 2041	5.65%	996		996
Senior Unsecured	March 2014	April 2044	4.80%	1,736		1,735
Senior Unsecured	November 2014	February 2045	4.50%	1,733		1,732
Senior Unsecured	September 2015	March 2046	4.75%	2,220		2,219
Senior Unsecured	September 2016	March 2047	4.15%	1,727		1,726
Senior Unsecured	September 2020	October 2050	2.80%	1,476		1,476
Total senior unsecured notes and term loan facility				25,571		30,295
Liability related to future royalties				1,124		1,107
Total debt, net				26,695		31,402
Less: current portion of long-term debt and other obligations, net				1,516		2,757
Total long-term debt, net				$	25,179	$	28,645

Senior Unsecured Notes and Term Loan Facility

In 2021, we repaid $4.75 billion of debt, consisting of $3.75 billion senior unsecured notes and $1.0 billion of our senior unsecured term loan facility. We repaid $1.0 billion of senior unsecured notes due April 2021 in the first quarter of 2021 and $1.25 billion of senior unsecured notes due December 2021 in the third quarter of 2021. Additionally, we repaid $500 million of senior unsecured floating rate notes due upon maturity in September 2021. In October 2021, we exercised our option to call $500 million of senior unsecured floating rate notes and $500 million of 0.75% senior unsecured notes, both having a final maturity date of September 2023. These two early repayments totaling $1.0 billion principal amount were made in the fourth quarter of 2021. In December 2021, we exercised our option to call $500 million of senior unsecured notes having a final maturity of March 2022. The notes were repaid in February 2022. No new debt was issued in 2021.

Our senior unsecured fixed rate notes may be redeemed at our option at a redemption price equal to the greater of (i) 100% of the principal amount of the notes to be redeemed and (ii) the sum, as determined by an independent investment banker, of the present values of the remaining scheduled payments of principal and interest on the notes to be redeemed (exclusive of interest accrued to the date of redemption) discounted to the redemption date on a semiannual basis at the Treasury Rate, plus a make-whole premium as defined in the indenture. The senior unsecured fixed rate notes also have a call feature, exercisable at our option, to redeem the notes at par in whole, or in part, on dates ranging from one month to two years prior to maturity. In each case, accrued and unpaid interest is also required to be redeemed to the date of redemption. The $1.5 billion of 0.75% senior unsecured notes due September 2023 also have a call feature, exercisable at our option, to redeem the notes at par, in whole or in part, after September 2021.

In the event of the occurrence of a change in control and a downgrade in the rating of our senior unsecured notes below investment grade by Moody’s Investors Service, Inc. and S&P Global Ratings, the holders may require us to purchase all or a portion of their notes at a price equal to 101% of the aggregate principal amount of the notes repurchased, plus accrued and unpaid interest to the date of repurchase. We are required to comply with certain covenants under our note indentures governing our senior unsecured notes. As of December 31, 2021 and 2020, we were not in violation of any covenants.

In September 2020, we entered into a commitment letter with a group of institutional lenders to provide for a three-year senior unsecured term loan facility in an aggregate principal amount of $1.0 billion. In October 2020, in connection with our acquisition of Immunomedics, we entered into a term loan credit agreement (the “Term Loan Facility”) and borrowed an aggregate principal amount of $1.0 billion. In 2021, we repaid $1.0 billion principal amount outstanding under the Term Loan Facility which was due upon maturity in October 2023.

Liability Related to Future Royalties

In connection with our acquisition of Immunomedics, we assumed a liability related to a funding arrangement, which was originally entered into by Immunomedics and RPI, prior to our acquisition of Immunomedics. The liability related to future royalties was primarily included in Long-term debt, net on our Consolidated Balance Sheets. See Note 6. Acquisitions for additional information.

Revolving Credit Facilities

In June 2020, we terminated our $2.5 billion five-year revolving credit facility maturing in May 2021 (the “2016 Revolving Credit Facility”) and entered into a new $2.5 billion five-year revolving credit facility maturing in June 2025 (the “2020 Revolving Credit Facility”). The 2020 Revolving Credit Facility can be used for working capital requirements and for general corporate purposes, including, without limitation, acquisitions. As of December 31, 2021 and 2020, there were no amounts outstanding under the 2020 Revolving Credit facility.

The 2020 Revolving Credit Facility contains customary representations, warranties, affirmative and negative covenants and events of default. As of December 31, 2021, we were in compliance with all covenants. Loans under the 2020 Revolving Credit Facility bear interest at either (i) the Eurodollar Rate plus the Applicable Percentage, or (ii) the Base Rate plus the Applicable Percentage, each as defined in the 2020 Revolving Credit Facility agreement. We may terminate or reduce the commitments, and may prepay any loans under the credit facility in whole or in part at any time without premium or penalty.

Contractual Maturities of Financing Obligations

The following table summarizes the aggregate future principal maturities of our senior unsecured notes as of December 31, 2021:


(in millions)	Amount
2022	$	1,500
2023	2,250
2024	1,750
2025	1,750
2026	2,750
Thereafter	15,750
Total	$	25,750

Interest Expense

Interest expense on our debt and credit facilities related to the contractual coupon rates and amortization of the debt discount and issuance costs was $1.0 billion in 2021, 2020 and 2019.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Leases

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

Leases

LEASES

Our operating leases consist primarily of properties and equipment for our administrative, manufacturing and R&D activities. Some of our leases include options to extend the terms for up to 15 years and some include options to terminate the lease within one year after the lease commencement date. As of December 31, 2021 and 2020, we did not have material finance leases. Operating lease expense, including variable costs and short-term leases, was $156 million, $171 million and $162 million in 2021, 2020 and 2019, respectively.

The following table summarizes balance sheet and other information related to our operating leases:


		December 31,
(in millions, except weighted average amounts)	Classification	2021			2020
Right-of-use assets, net	Other long-term assets	$	542		$	646
Lease liabilities - current	Accrued and other current liabilities	$	101		$	107
Lease liabilities - noncurrent	Other long-term obligations	$	489		$	608
Weighted average remaining lease term		8.5 years			8.6 years
Weighted average discount rate		3.00		%	3.32		%

The following table summarizes other supplemental information related to our operating leases:


	Year Ended December 31,
(in millions)	2021		2020
Cash paid for amounts included in the measurement of lease liabilities	$	123	$	66
Right-of-use assets obtained in exchange for lease liabilities	$	88	$	88

The following table summarizes a maturity analysis of our operating lease liabilities showing the aggregate lease payments as of December 31, 2021:


(in millions)	Amount
2022	$	117
2023	108
2024	92
2025	61
2026	50
Thereafter	249
Total undiscounted lease payments	677
Less: imputed interest	87
Total discounted lease payments	$	590

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Legal Proceedings We are a party to various legal actions. The most significant of these are described below. We recognize accruals for such actions to the extent that we conclude that a loss is both probable and reasonably estimable. We accrue for the best estimate of a loss within a range; however, if no estimate in the range is better than any other, then we accrue the minimum amount in the range. If we determine that a material loss is reasonably possible and the loss or range of loss can be estimated, we disclose the possible loss. Unless otherwise noted, the outcome of these matters either is not expected to be material or is not possible to determine such that we cannot reasonably estimate the maximum potential exposure or the range of possible loss. In the third quarter of 2021, we reversed a $175 million previously recorded litigation accrual following a favorable court decision for the litigation related to axicabtagene ciloleucel described below. In the fourth quarter of 2021, we recorded an accrual of $1.25 billion in Accrued and other current liabilities on our Consolidated Balance Sheets for the settlement related to bictegravir litigation described below. Litigation Related to Sofosbuvir In 2012, we acquired Pharmasset, Inc. Through the acquisition, we acquired sofosbuvir, a nucleotide analog that acts to inhibit the replication of HCV. In 2013, we received approval from FDA for sofosbuvir, now known commercially as Sovaldi. Sofosbuvir is also included in all of our marketed HCV products. We have received a number of litigation claims regarding sofosbuvir. While we have carefully considered these claims both prior to and following the acquisition and believe they are without merit, we cannot predict the ultimate outcome of such claims or range of loss. We are aware of patents and patent applications owned by third parties that have been or may in the future be alleged by such parties to cover the use of our HCV products. If third parties obtain valid and enforceable patents, and successfully prove infringement of those patents by our HCV products, we could be required to pay significant monetary damages. We cannot predict the ultimate outcome of intellectual property claims related to our HCV products. We have spent, and will continue to spend, significant resources defending against these claims. Litigation with the University of Minnesota The University of Minnesota (the “University”) has obtained U.S. Patent No. 8,815,830 (the “’830 patent”), which purports to broadly cover nucleosides with antiviral and anticancer activity. In 2016, the University filed a lawsuit against us in the U.S. District Court for the District of Minnesota, alleging that the commercialization of sofosbuvir-containing products infringes the ’830 patent. We believe the ’830 patent is invalid and will not be infringed by the continued commercialization of sofosbuvir. In 2017, the court granted our motion to transfer the case to California. We have also filed petitions for inter partes review with the U.S. Patent and Trademark Office Patent Trial and Appeal Board (“PTAB”) alleging that all asserted claims are invalid for anticipation and obviousness. The PTAB instituted one of these petitions and a merits hearing was held in February 2021. In 2018, the U.S. District Court for the Northern District of California stayed the litigation until after the PTAB concludes the inter partes review that it has initiated. In May 2021, the PTAB issued a written decision finding the asserted claims of the University’s patent invalid. In July 2021, the University appealed this decision. The litigation in the U.S. District Court will remain stayed through the appeal proceedings. Litigation with NuCana plc. (“NuCana”) NuCana has obtained European Patent No. 2,955,190 (the “EP ’190 patent”) that allegedly covers sofosbuvir. In opposition proceedings before the European Patent Office (“EPO”) held in February 2021, the EPO Opposition Division upheld the validity of the EP ’190 patent in amended form. We believe that the amended EP ’190 patent claims are invalid. Subsequently, we initiated proceedings to invalidate the UK counterpart of the EP ’190 patent in the High Court of England & Wales. In March 2021, NuCana filed a counterclaim against us in the High Court of England & Wales alleging patent infringement of the UK counterpart and seeking damages and other relief. In April 2021, NuCana also filed a lawsuit against us in Germany at the Landgericht Düsseldorf alleging patent infringement of the German counterpart of the EP ’190 patent and seeking damages and injunctive relief. The hearing date for the German NuCana case has been scheduled for May 2022. The hearing date for the UK NuCana case has been scheduled for January 2023. Litigation Related to Axicabtagene Ciloleucel In October 2017, Juno Therapeutics, Inc. and Sloan Kettering Cancer Center (collectively, “Juno”) filed a lawsuit against us in the U.S. District Court for the Central District of California, alleging that the commercialization of axicabtagene ciloleucel, sold commercially as Yescarta, infringes on U.S. Patent No. 7,446,190 (the “’190 patent”). A jury trial was held on the ’190 patent, and in December 2019, the jury found that the asserted claims of the ’190 patent were valid, and that we willfully infringed the asserted claims of the ’190 patent. The jury also awarded Juno damages in amounts of $585 million in an upfront payment and a 27.6% running royalty from October 2017 through the date of the jury’s verdict. The parties filed post-trial motions in the first quarter of 2020, and the trial judge entered a judgment in April 2020. The trial judge affirmed the jury’s verdict, enhanced the past damages by 50% and maintained the royalties on future Yescarta sales at 27.6%. In April 2020, we filed an appeal seeking to reverse the judgment or obtain a new trial due to errors made by the trial judge, and in July 2021, the appeals court heard oral arguments. In August 2021, the Court of Appeals for the Federal Circuit (the “CAFC”) reversed the jury verdict, finding the asserted claims of Juno’s patent invalid. In October 2021, Juno filed a petition for rehearing with the CAFC. In January 2022, the CAFC denied Juno’s petition for rehearing. We believe that the likelihood of a material adverse outcome in this matter is remote. Litigation Related to Bictegravir In 2018, ViiV Healthcare Company (“VHC”) filed a lawsuit against us in the U.S. District Court of Delaware, alleging that the commercialization of bictegravir, sold commercially in combination with tenofovir alafenamide and emtricitabine as Biktarvy, infringes VHC’s U.S. Patent No. 8,129,385 (the “’385 patent”) covering VHC’s dolutegravir. Bictegravir is structurally different from dolutegravir, and we believe that bictegravir does not infringe the claims of the ’385 patent. In its lawsuit, VHC was seeking billions of dollars for alleged damages comprised of VHC’s lost profits and a royalty on U.S. sales of bictegravir from launch through the trial. In addition, should a court find that we are liable for infringement, we also expected VHC to seek a royalty on U.S. sales after the trial. In 2018, VHC also filed a lawsuit against us in the Federal Court of Canada, alleging that our activities relating to our bictegravir compound infringes VHC’s Canadian Patent No. 2,606,282 (the “’282 patent”), which was issued to Shionogi & Co. Ltd. and VHC. The ’282 patent is the compound patent covering VHC’s dolutegravir. We believe that bictegravir does not infringe the claims of the ’282 patent. In November and December 2019, VHC filed lawsuits in France, Germany, Ireland and the UK asserting the relevant national designations of European Patent No. 3 045 206; in Australia asserting Australian Patent No. 2006239177; in Japan asserting Japanese Patent No. 4295353; and in Korea asserting Korean Patent Nos. 1848819 and 1363875. These patents all relate to molecules that VHC claims would act as integrase inhibitors. We believe that bictegravir does not infringe any valid claims of VHC’s patents and have prevailed in court proceedings to date in Canada and Germany. On February 1, 2022, Gilead reached an agreement (the “Settlement”) with VHC, ViiV Healthcare UK (No.3) Limited, ViiV Healthcare UK Limited, Shionogi & Co., Ltd. and GlaxoSmithKline Mercury Limited (collectively, “ViiV”) for a global resolution of all pending or potential claims related to Gilead’s sales of Biktarvy, including the litigation pending in the U.S. District Court of Delaware and other jurisdictions outside the United States as described above. In February 2022, the lawsuit pending in the United States was dismissed as well as the lawsuits in Canada, France, Ireland, the UK, Australia, Japan and Korea. Pursuant to the terms of the Settlement, ViiV grants Gilead a broad worldwide license and covenant not to sue relating to any past, present or future development or commercialization of bictegravir. In connection with the Settlement, Gilead (1) made a one-time payment to ViiV of $1.25 billion in the first quarter of 2022, and (2) will provide ViiV an ongoing royalty at a rate of 3% on future sales of Biktarvy and the bictegravir component of bictegravir-containing products in the United States until October 5, 2027. In connection with the Settlement, Gilead recorded a pre-tax charge of $1.25 billion to Cost of goods sold on our Consolidated Statements of Income in the fourth quarter of 2021. Litigation Relating to Pre-Exposure Prophylaxis In August 2019, we filed petitions requesting inter partes review of U.S. Patent Nos. 9,044,509, 9,579,333, 9,937,191 and 10,335,423 (collectively, “HHS Patents”) by PTAB. The HHS Patents are assigned to the U.S. Department of Health and Human Services (“HHS”) and purport to claim a process of protecting a primate host from infection by an immunodeficiency retrovirus by administering a combination of emtricitabine or tenofovir disoproxil fumarate (“TDF”) prior to exposure of the host to the immunodeficiency retrovirus, a process commonly known as pre-exposure prophylaxis (“PrEP”). In November 2019, the U.S. Department of Justice filed a lawsuit against us in the U.S. District Court of Delaware, alleging that the sale of Truvada and Descovy for use as PrEP infringes the HHS Patents. In February 2020, PTAB declined to institute our petitions for inter partes review of the HHS Patents. In April 2020, we filed a breach of contract lawsuit against the U.S. federal government in the U.S. Court of Federal Claims, alleging violations of four material transfer agreements (“MTAs”) related to the research underlying the HHS Patents and a clinical trial agreement (“CTA”) by the U.S. Centers for Disease Control and Prevention related to PrEP research. Although we cannot predict with certainty the ultimate outcome of these litigation matters, we believe that the U.S. federal government breached the MTAs and CTA, that Truvada and Descovy do not infringe the HHS Patents and that the HHS Patents are invalid over prior art descriptions of Truvada’s use for PrEP and post-exposure prophylaxis as well because physicians and patients were using the claimed methods years before HHS filed the applications for the patents. A trial date for the lawsuit in the Court of Federal Claims has been set for June 2022, and a trial date for the lawsuit in the District Court of Delaware has been set for May 2023. Litigation with Generic Manufacturers As part of the approval process for some of our products, FDA granted us a New Chemical Entity (“NCE”) exclusivity period during which other manufacturers’ applications for approval of generic versions of our product will not be approved. Generic manufacturers may challenge the patents protecting products that have been granted NCE exclusivity one year prior to the end of the NCE exclusivity period. Generic manufacturers have sought and may continue to seek FDA approval for a similar or identical drug through an abbreviated new drug application (“ANDA”), the application form typically used by manufacturers seeking approval of a generic drug. The sale of generic versions of our products prior to their patent expiration would have a significant negative effect on our revenues and results of operations. To seek approval for a generic version of a product having NCE status, a generic company may submit its ANDA to FDA four years after the branded product’s approval. Starting in December 2019, we received letters from Lupin Ltd., Apotex Inc., Shilpa Medicare Ltd. (“Shilpa”), Sunshine Lake Pharma Co. Ltd. (“Sunshine Lake”), Laurus Labs, Natco Pharma Ltd., Macleods Pharma Ltd., Hetero Labs Ltd. and Cipla Ltd. (collectively, “Generic Manufacturers”) indicating that they have submitted ANDAs to FDA requesting permission to market and manufacture generic versions of certain of our TAF-containing products. Between them, these Generic Manufacturers seek to market generic versions of Odefsey, Descovy and Vemlidy. The Generic Manufacturers have challenged the validity of two to four patents listed on the Orange Book and associated with TAF. We filed lawsuits against the Generic Manufacturers, and we intend to enforce and defend our intellectual property. In November 2021, we reached an agreement with Shilpa to resolve the lawsuit against Shilpa. In addition, in January 2022, we reached an agreement with Sunshine Lake to resolve the lawsuit against Sunshine Lake. The settlement agreements have been filed with the U.S. Federal Trade Commission and the U.S. Department of Justice as required by law. In October 2021, we received a letter from Lupin Ltd. (“Lupin”) indicating that it has submitted an ANDA to FDA requesting permission to market and manufacture a generic version of Symtuza, a product commercialized by Janssen and for which Gilead shares in revenues. In November 2021, we, along with Janssen Products, L.P. and Janssen, filed a patent infringement lawsuit against Lupin as co-plaintiffs in the U.S. District Court of Delaware. We separately filed an additional lawsuit against Lupin asserting infringement of two additional patents in the same court. European Patent Claims In 2015, several parties filed oppositions in the EPO requesting revocation of one of our granted European patents covering sofosbuvir that expires in 2028. In 2016, the EPO upheld the validity of certain claims of our sofosbuvir patent. We have appealed this decision, seeking to restore all of the original claims, and several of the original opposing parties have also appealed, requesting full revocation. An appeal hearing originally scheduled for July 2021 has been canceled and a new date has not yet been set by the EPO. In 2017, several parties filed oppositions in the EPO requesting revocation of our granted European patent relating to sofosbuvir that expires in 2024. The EPO conducted an oral hearing for this opposition in 2018 and upheld the claims. Two of the original opposing parties have appealed, requesting full revocation. In 2016, several parties filed oppositions in the EPO requesting revocation of our granted European patent covering TAF that expires in 2026. In 2017, the EPO upheld the validity of the claims of our TAF patent. Three parties have appealed this decision. The appeal hearing was held in March 2021, and the validity of all claims were upheld. In 2017, several parties filed oppositions in the EPO requesting revocation of our granted European patent relating to TAF hemifumarate that expires in 2032. In 2019, the EPO upheld the validity of the claims of our TAF hemifumarate patent. Three parties have appealed this decision. In 2016, three parties filed oppositions in the EPO requesting revocation of our granted European patent covering cobicistat that expires in 2027. In 2017, the EPO upheld the validity of the claims of our cobicistat patent. Two parties have appealed this decision. The appeal process may take several years for all EPO opposition proceedings. While we are confident in the strength of our patents, we cannot predict the ultimate outcome of these oppositions. If we are unsuccessful in defending these oppositions, some or all of our patent claims may be narrowed or revoked and the patent protection for sofosbuvir, TAF, TAF hemifumarate and cobicistat in the EU could be substantially shortened or eliminated entirely. If our patents are revoked, and no other European patents are granted covering these compounds, our exclusivity may be based entirely on regulatory exclusivity granted by EMA. If we lose patent protection for any of these compounds, our revenues and results of operations could be negatively impacted for the years including and succeeding the year in which such exclusivity is lost. Antitrust and Consumer Protection We (along with Bristol-Myers Squibb Company (“BMS”) and Johnson & Johnson, Inc.) have been named as defendants in class action lawsuits filed in 2019 and 2020 related to various drugs used to treat HIV, including drugs used in combination antiretroviral therapy. Plaintiffs allege that we (and the other defendants) engaged in various conduct to restrain competition in violation of federal and state antitrust laws and state consumer protection laws. The lawsuits, which have been consolidated, are pending in the U.S. District Court for the Northern District of California. The lawsuits seek to bring claims on behalf of two nationwide classes—one of direct purchasers consisting largely of wholesalers, and another of indirect or end-payor purchasers, including health insurers and individual patients. Plaintiffs seek damages, permanent injunctive relief and other relief. In the fall of 2021, several plaintiffs filed separate lawsuits effectively opting out of the class action cases, asserting claims that are substantively the same as the putative classes. These cases have been coordinated with the class actions. Trial is set for March 2023. In September 2020, we, along with generic manufacturers Cipla Ltd. and Cipla USA Inc. (together, “Cipla”), were named as defendants in a class action lawsuit filed in the U.S. District Court for the Northern District of California by Jacksonville Police Officers and Fire Fighters Health Insurance Trust (“Jacksonville Trust”) on behalf of end-payor purchasers. Jacksonville Trust claims that the 2014 settlement agreement between us and Cipla, which settled a patent dispute relating to patents covering our Emtriva, Truvada and Atripla products and permitted generic entry prior to patent expiry, violates certain federal and state antitrust and consumer protection laws. The Plaintiff seeks damages, permanent injunctive relief and other relief. In February 2021, we along with BMS and Teva Pharmaceutical Industries Ltd. were named as defendants in a lawsuit filed in the First Judicial District Court for the State of New Mexico, County of Santa Fe by the New Mexico Attorney General. The New Mexico Attorney General alleges that we (and the other defendants) restrained competition in violation of New Mexico antitrust and consumer protection laws. The New Mexico Attorney General seeks damages and other relief. While we believe these cases are without merit, we cannot predict the ultimate outcome. If plaintiffs are successful in their claims, we could be required to pay significant monetary damages or could be subject to permanent injunctive relief awarded in favor of plaintiffs. Product Liability We have been named as a defendant in one class action lawsuit and various product liability lawsuits related to Viread, Truvada, Atripla, Complera and Stribild. Plaintiffs allege that Viread, Truvada, Atripla, Complera and/or Stribild caused them to experience kidney, bone and/or tooth injuries. The lawsuits, which are pending in state or federal court in California, Delaware, Maryland, Missouri and New Jersey, involve more than 27,000 plaintiffs. Plaintiffs in these cases seek damages and other relief on various grounds for alleged personal injury and economic loss. We intend to vigorously defend ourselves in these actions. While we believe these cases are without merit, we cannot predict the ultimate outcome. If plaintiffs are successful in their claims, we could be required to pay significant monetary damages. Government Investigation In 2017, we received a subpoena from the U.S. Attorney’s Office for the Southern District of New York requesting documents related to our promotional speaker programs for HIV. We are cooperating with this inquiry. Qui Tam Litigation A former sales employee filed a qui tam lawsuit against Gilead in March 2017 in U.S. District Court for the Eastern District of Pennsylvania. Following the government’s decision not to intervene in the suit, the case was unsealed in December 2020. The lawsuit alleges that certain of Gilead’s HCV sales and marketing activities violated the federal False Claims Act and various state false claims acts. The relator seeks all available relief under these statutes. Two former employees filed a qui tam lawsuit against Gilead in April 2020 in California state court. Following the California Attorney General’s Office’s decision not to intervene, relators served Gilead with their complaint in August 2020. The complaint alleges violations of the California False Claims Act (“CFCA”) and employment law claims. Relators seek all available relief under the CFCA. In December 2021, Gilead and relators executed a settlement agreement to resolve the lawsuit, and in February 2022, the court issued an order dismissing the lawsuit with prejudice. The settlement does not have a material impact to our Consolidated Financial Statements. Health Choice Advocates, LLC (“Health Choice”) filed a qui tam lawsuit against Gilead in April 2020 in New Jersey state court. Following the New Jersey Attorney General’s Office’s decision not to intervene in the suit, Health Choice served us with their original complaint in August 2020. The lawsuit alleges that Gilead violated the New Jersey False Claims Act through our clinical educator programs for Sovaldi and Harvoni and our HCV and HIV patient access programs. The lawsuit seeks all available relief under the New Jersey False Claims Act. In April 2021, the trial court granted our motion to dismiss with prejudice. Health Choice has appealed the trial court’s dismissal. Health Choice filed another qui tam lawsuit against Gilead in May 2020 making similar allegations in Texas state court. Following the Texas Attorney General’s Office’s decision not to intervene in the suit, Health Choice served us with their original complaint in October 2020. The lawsuit alleges that Gilead violated the Texas Medicare Fraud Prevention Act (“TMFPA”) through our clinical educator programs for Sovaldi and Harvoni and our HCV and HIV patient access programs. The lawsuit seeks all available relief under the TMFPA. In September 2021, the Texas Court of Appeals for the Sixth Court Appeals District granted our request to stay the Texas litigation. The case is stayed pending final judgment in the Eastern District of Pennsylvania lawsuit filed in March 2017, as discussed above. We intend to vigorously defend ourselves in these actions. While we believe these cases are without merit, we cannot predict the ultimate outcomes. If any of these plaintiffs are successful in their claims, we could be required to pay significant monetary damages. Securities Litigation Immunomedics and several of its former officers and directors have been named as defendants in putative class actions filed in 2018 and 2019, which were consolidated in September 2019. Plaintiffs filed a consolidated complaint in November 2019 and an amended complaint in July 2021. Plaintiffs allege that Immunomedics and the individual defendants violated the federal securities laws in connection with Immunomedics’ Biologics License Application for Trodelvy, and seek certification of a class of shareholders, damages and other relief. The consolidated lawsuit is pending in the U.S. District Court for the District of New Jersey. While we believe this case is without merit, we cannot predict the ultimate outcome. If plaintiffs are successful in their claims, we could be required to pay significant monetary damages. Other Matters We are a party to various legal actions that arose in the ordinary course of our business. We do not believe that these other legal actions will have a material adverse impact on our consolidated business, financial position or results of operations. Other Commitments In the normal course of business, we enter into firm purchase commitments related to inventory. As of December 31, 2021, these commitments for the next five years were approximately $1.1 billion in 2022, $450 million in 2023, $243 million in 2024, $60 million in 2025 and $31 million in 2026.

Stockholders' Equity

12 Months Ended

Dec. 31, 2021

Stockholders' Equity Note [Abstract]

Stockholders' Equity

STOCKHOLDERS’ EQUITY

Stock Repurchase Programs

In the first quarter of 2016, our Board of Directors authorized a $12.0 billion stock repurchase program (“2016 Program”) under which repurchases may be made in the open market or in privately negotiated transactions. We started repurchases under the 2016 Program in April 2016.

In the first quarter of 2020, our Board of Directors authorized a new $5.0 billion stock repurchase program (“2020 Program”), which will commence upon the completion of the 2016 Program. Purchases under the 2020 Program may be made in the open market or in privately negotiated transactions.

As of December 31, 2021, the remaining authorized repurchase amount under both programs was $6.3 billion.

The following table summarizes our stock repurchases under the 2016 Program:


	Year Ended December 31,
(in millions, except per share amounts)	2021		2020		2019
Shares repurchased and retired	8		22		26
Amount	$	546	$	1,583	$	1,749
Average price per share	$	66.58	$	70.64	$	66.36

In addition to repurchases from the 2016 Program and 2020 Program, we repurchased shares of common stock withheld by us from employee restricted stock awards to satisfy our applicable tax withholding obligations. These shares are excluded from the table above.

We use the par value method of accounting for our stock repurchases. Under the par value method, common stock is first charged with the par value of the shares involved. The excess of the cost of shares acquired over the par value is allocated to additional paid-in capital based on an estimated average sales price per issued share with the excess amounts charged to retained earnings.

Dividends

The following table summarizes cash dividends declared on our common stock:


	2021				2020
(in millions, except per share amounts)	Dividend Per Share		Amount		Dividend Per Share		Amount
First quarter	$	0.71	$	906	$	0.68	$	867
Second quarter	0.71		903		0.68		866
Third quarter	0.71		905		0.68		866
Fourth quarter	0.71		904		0.68		865
Total	$	2.84	$	3,618	$	2.72	$	3,464

Our restricted stock and performance share awards or units have dividend equivalent rights entitling holders to dividend equivalents to be paid upon vesting for each share of the underlying unit.

On February 1, 2022, we announced that our Board of Directors declared a quarterly cash dividend of $0.73 per share of our common stock, with a payment date of March 30, 2022 to all stockholders of record as of the close of business on March 15, 2022. Future dividends are subject to declaration by our Board of Directors.

Preferred Stock

We have 5 million shares of authorized preferred stock issuable in series. Our Board is authorized to determine the designation, powers, preferences and rights of any such series. There was no preferred stock outstanding as of December 31, 2021 and 2020.

Accumulated Other Comprehensive Income

The following table summarizes the changes in AOCI by component, net of tax:


(in millions)	Foreign Currency Translation, Net of Tax		Unrealized Gains and Losses on Available-for-Sale Debt Securities, Net of Tax		Unrealized Gains and Losses on Cash Flow Hedges, Net of Tax		Total
Balance as of December 31, 2018	$	47	$	(52)	$	85	$	80
Net unrealized gain	6		54		72		132
Reclassifications to net income	—		(1)		(126)		(127)
Net current period other comprehensive income (loss)	6		53		(54)		5
Balance as of December 31, 2019	$	53	$	1	$	31	$	85
Net unrealized gain (loss)	(2)		43		(103)		(62)
Reclassifications to net income	—		(42)		(41)		(83)
Net current period other comprehensive income (loss)	(2)		1		(144)		(145)
Balance as of December 31, 2020	$	51	$	2	$	(113)	$	(60)
Net unrealized gain (loss)	$	(38)	$	(6)	$	129	$	85
Reclassifications to net income	—		—		58		58
Net current period other comprehensive income (loss)	(38)		(6)		187		143
Balance as of December 31, 2021	$	13	$	(4)	$	74	$	83

The amounts reclassified to net income for gains and losses on cash flow hedges are recorded as part of Product sales on our Consolidated Statements of Income. See Note 5. Derivative Financial Instruments for additional information. The amounts reclassified to net income for gains and losses on available-for-sale debt securities are recorded as part of Other income (expense), net, on our Consolidated Statements of Income. The income tax impact allocated to each component of other comprehensive income was not material for the periods presented.

- Definition

The entire disclosure for shareholders' equity comprised of portions attributable to the parent entity and noncontrolling interest, including other comprehensive income. Includes, but is not limited to, balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings, accumulated balance for each classification of other comprehensive income and amount of comprehensive income.

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+ Details

Employee Benefits

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Employee Benefits

EMPLOYEE BENEFITS

Equity Incentive Plans

In May 2004, our stockholders approved and we adopted the Gilead Sciences, Inc. 2004 Equity Incentive Plan (as amended, the “2004 Plan”). The 2004 Plan authorized the issuance of a total of 309 million shares of common stock.

As part of the Forty Seven acquisition, we assumed the Forty Seven, Inc. 2018 Equity Incentive Plan, which we subsequently amended and restated as the Gilead Sciences, Inc. 2018 Equity Incentive Plan (as amended and restated, the “2018 Plan”). The aggregate amount of shares that may be issued under the 2018 Plan on or after the assumption date will not exceed 12 million shares. As part of the Immunomedics acquisition, we assumed the Immunomedics Amended and Restated 2014 Long-Term Incentive Plan (the “Immunomedics Plan” and referred together with the 2004 Plan and 2018 Plan as the “Plans”), which we subsequently merged into the 2004 Plan. The aggregate amount of shares that may be issued under the Immunomedics Plan on or after the assumption date will not exceed 26 million shares. See Note 6. Acquisitions for additional information on the settlement of stock awards.

The Plans are broad based incentive plans that provide for the grant of equity-based awards, including stock options, restricted stock units, restricted stock awards and performance share awards, to employees, directors and consultants. As of December 31, 2021, a total of 82 million shares remain available for future grant under the Plans.

Stock Options

The Plans provide for option grants designated as either non-qualified or incentive stock options. All stock options granted after January 1, 2006 have been non-qualified stock options. Employee stock options generally vest over three or four years. All options are exercisable over a period not to exceed the contractual term of ten years from the date the stock options are issued and are granted at prices not less than the fair market value of our common stock on the grant date. Stock option exercises are settled with common stock from the Plans’ previously authorized and available pool of shares.

The following table summarizes activity and related information under our stock option plans. All option grants presented in the table had exercise prices not less than the fair value of the underlying common stock on the grant date:


	Shares (in millions)	Weighted- Average Exercise Price (in dollars)		Weighted-Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in millions)
Outstanding as of December 31, 2020	16.6	$	69.40
Granted	3.8	$	64.77
Forfeited	(0.9)	$	67.67
Expired	(1.1)	$	82.11
Exercised	(1.6)	$	37.46
Outstanding as of December 31, 2021	16.8	$	70.60	5.34	$	101
Exercisable as of December 31, 2021	11.2	$	72.43	3.67	$	68
Expected to vest, net of estimated forfeitures as of December 31, 2021	5.3	$	67.01	8.61	$	32

Aggregate intrinsic value represents the value of our closing stock price on the last trading day of the year in excess of the weighted-average exercise price multiplied by the number of options outstanding or exercisable. Total intrinsic value of options exercised was $48 million, $179 million and $209 million for 2021, 2020 and 2019, respectively.

The weighted-average grant date fair value of the stock options granted was $10.05 per share, $11.69 per share and $12.15 per share for 2021, 2020 and 2019, respectively.

As of December 31, 2021, there was $47 million of unrecognized compensation cost related to stock options, which is expected to be recognized over an estimated weighted-average period of 2.3 years.

Restricted Stock and Performance Share Awards

We grant time-based RSUs to certain employees as part of our annual employee equity compensation review program as well as to new hire employees and to non-employee members of our Board. RSUs are share-based awards that entitle the holder to receive freely tradable shares of our common stock upon vesting. RSUs generally vest over three or four years from the date of grant. The fair value of an RSU is equal to the closing price of our common stock on the grant date.

We grant PSUs which vest upon the achievement of specified market or performance goals, which could include achieving a total shareholder return compared to a pre-determined peer group or achieving revenue targets. The actual number of common shares ultimately issued is calculated by multiplying the number of PSUs by a payout percentage ranging from 0% to 200%, and these awards generally vest only when a committee (or subcommittee) of our Board has determined that the specified market and performance goals have been achieved. The fair value of each PSU is estimated at the date of grant or when performance objectives are defined for the grants. Depending on the terms of the award, fair value on the date of grant is determined based on either the Monte Carlo valuation methodology or the closing stock price on the date of grant.

In addition, we have also granted other PSUs to certain of our employees under the 2004 Plan. The vesting of these awards is subject to the achievement of specified individual performance goals, typically within a one to two year period. The fair value of such an award is equal to the closing price of our common stock on the grant date.

The following table summarizes our RSU and PSU activity and related information:


	RSUs			PSUs
(in millions, except per share amounts)	Shares	Weighted- Average Grant Date Fair Value Per Share		Shares(1)	Weighted- Average Grant Date Fair Value Per Share(1)
Outstanding as of December 31, 2020	19.5	$	69.80	0.6	$	84.87
Granted	11.9	$	65.42	0.3	$	71.31
Vested	(7.0)	$	70.30	(0.1)	$	88.36
Forfeited	(3.5)	$	67.77	(0.1)	$	78.37
Outstanding as of December 31, 2021	20.9	$	67.48	0.7	$	79.13

________________________________

(1) Weighted-average grant-date fair value per share excludes shares related to grants that currently have no grant date as the performance objectives have not yet been defined.

The weighted-average grant date fair value of RSUs granted was $65.42 per share, $70.94 per share and $64.31 per share for 2021, 2020 and 2019, respectively. The weighted-average grant date fair value of PSUs granted was $71.31 per share, $83.64 per share and $68.30 per share for 2021, 2020 and 2019, respectively. The total grant date fair value of our vested RSUs and PSUs was $503 million, $479 million and $450 million for 2021, 2020 and 2019, respectively, and total fair value as of the respective vesting dates was $471 million, $459 million and $372 million for 2021, 2020 and 2019, respectively.

As of December 31, 2021, there was $917 million of unrecognized compensation cost related to unvested RSUs and PSUs, which is expected to be recognized over a weighted-average period of 2.2 years.

Employee Stock Purchase Plan

Under our Employee Stock Purchase Plan and the International Employee Stock Purchase Plan (together, as amended, the “ESPP”), employees can purchase shares of our common stock based on a percentage of their compensation subject to certain limits. The purchase price per share is equal to the lower of 85% of the fair market value of our common stock on the offering date or the purchase date. The ESPP offers a six-month look-back feature as well as an automatic reset feature that provides for an offering period to be reset to a new lower-priced offering if the offering price of the new offering period is less than that of the current offering period. ESPP purchases are settled with common stock from the ESPP’s previously authorized and available pool of shares. During 2021, 2 million shares were issued under the ESPP for $111 million. A total of 79 million shares of common stock have been authorized for issuance under the ESPP, and there were 5 million shares available for issuance under the ESPP as of December 31, 2021.

Stock-Based Compensation

The following table summarizes total stock-based compensation expenses included on our Consolidated Statements of Income:


	Year Ended December 31,
(in millions)	2021		2020		2019
Cost of goods sold	$	40	$	109	$	48
Research and development expenses	287		462		289
Selling, general and administrative expenses	308		505		299
Stock-based compensation expense included in total costs and expenses(1)	635		1,076		636
Income tax effect(2)	(100)		(222)		2
Stock-based compensation expense, net of tax	$	535	$	854	$	638

________________________________

(1) Pre-tax stock-based compensation expense for the year ended December 31, 2020 of $1.1 billion included $643 million non-cash stock-based expense and $289 million and $144 million of accelerated post-acquisition stock-based expense related to the acquisitions of Immunomedics and Forty Seven, respectively. See Note 6. Acquisitions for additional information.

(2) Income tax effect for the year ended December 31, 2019 included a $114 million income tax expense following the U.S. Court of Appeals decision in Altera Corp v. Commissioner, which requires related parties in an intercompany cost sharing arrangement to share expenses related to stock-based compensation.

Stock-based compensation is recognized as expense over the requisite service periods on our Consolidated Statements of Income using the straight-line expense attribution approach, reduced for estimated forfeitures. We estimate forfeitures based on our historical experience. The requisite service period could be shorter than the vesting period if an employee is retirement eligible.

Valuation Assumptions

Fair value of options granted under our Plans and purchases under our ESPP were estimated at grant or purchase dates using a Black-Scholes option valuation model. The Black-Scholes option valuation model was developed for use in estimating the fair value of traded options, which have no vesting restrictions and are fully transferable. In addition, option valuation models require the input of highly subjective assumptions, including expected stock price volatility and expected award life.

We used the following assumptions to calculate the estimated fair value of the awards:


	Year Ended December 31,
	2021		2020		2019
Expected volatility:
Stock options	29	%	29	%	27	%
ESPP	25	%	28	%	27	%
Expected term in years:
Stock options	5.0		5.0		5.5
ESPP	0.5		0.5		0.5
Risk-free interest rate:
Stock options	0.8	%	0.8	%	2.3	%
ESPP	0.1	%	0.6	%	1.8	%
Expected dividend yield	4.4	%	4.0	%	3.6	%

The fair value of stock options granted was calculated using the single option approach. We use a blend of historical volatility along with implied volatility for traded options on our common stock to determine our expected volatility. The expected term of stock-based awards represents the weighted-average period the awards are expected to remain outstanding. We estimate the weighted-average expected term based on historical cancellation and historical exercise data related to our stock options as well as the contractual term and vesting terms of the awards. The risk-free interest rate is based upon observed interest rates appropriate for the term of the stock-based awards. The dividend yield is based on our history and expectation of dividend payouts.

Deferred Compensation

We maintain a retirement saving plan under which eligible U.S. employees may defer compensation for income tax purposes under Section 401(k) of the Internal Revenue Code (the Gilead Sciences 401k Plan). In certain foreign subsidiaries, we maintain defined benefit plans as required by local regulatory requirements. Our total matching contribution expense under the Gilead Sciences 401k Plan and other defined benefit plans was $166 million, $144 million and $110 million during 2021, 2020 and 2019, respectively.

We maintain a deferred compensation plan under which our directors and key employees may defer compensation. Amounts deferred by participants are deposited into a rabbi trust. The total assets and liabilities associated with the deferred compensation plan were $261 million and $218 million as of December 31, 2021 and 2020, respectively.

Net Income Per Share Attributable to Gilead Common Shareholders

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Net Income Per Share Attributable to Gilead Common Shareholders

NET INCOME PER SHARE ATTRIBUTABLE TO GILEAD COMMON STOCKHOLDERS

Basic net income per share attributable to Gilead common stockholders is calculated based on the weighted-average number of shares of our common stock outstanding during the period. Diluted net income per share attributable to Gilead common stockholders is calculated based on the weighted-average number of shares of our common stock and other dilutive securities outstanding during the period. The potentially dilutive shares of our common stock resulting from the assumed exercise of outstanding stock options and equivalents were determined under the treasury stock method.

Potential shares of common stock excluded from the computation of diluted net income per share attributable to Gilead common shareholders because their effect would have been antidilutive were 15 million, 13 million and 14 million during 2021, 2020 and 2019, respectively.

The following table shows the calculation of basic and diluted net income per share attributable to Gilead common stockholders:


	Year Ended December 31,
(in millions, except per share amounts)	2021		2020		2019
Net income attributable to Gilead	$	6,225	$	123	$	5,386
Shares used in per share calculation - basic	1,256		1,257		1,270
Dilutive effect of stock options and equivalents	6		6		7
Shares used in per share calculation - diluted	1,262		1,263		1,277
Net income per share attributable to Gilead common stockholders - basic	$	4.96	$	0.10	$	4.24
Net income per share attributable to Gilead common stockholders - diluted	$	4.93	$	0.10	$	4.22

Income Taxes

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Income Taxes

INCOME TAXES

Income before income taxes consists of the following:


	Year Ended December 31,
(in millions)	2021		2020		2019
Domestic	$	8,587	$	2,505	$	4,112
Foreign	(309)		(836)		1,048
Income before income taxes	$	8,278	$	1,669	$	5,160

The Income tax (expense) benefit consists of the following:


	Year Ended December 31,
(in millions)	2021		2020		2019
Federal:
Current	$	(1,776)	$	(1,450)	$	(1,646)
Deferred	250		164		843
	(1,526)		(1,286)		(803)
State:
Current	(228)		(198)		(135)
Deferred	(185)		97		42
	(413)		(101)		(93)
Foreign:
Current	(185)		(155)		(124)
Deferred	47		(38)		1,224
	(138)		(193)		1,100
Income tax (expense) benefit	$	(2,077)	$	(1,580)	$	204

The 2019 income tax benefit included a $1.2 billion deferred tax benefit related to intangible asset transfers from a foreign subsidiary to Ireland and the United States. In the fourth quarter of 2019, we completed an intra-entity asset transfer of certain intangible assets from a foreign subsidiary to Ireland. The transaction resulted in a step-up of the Irish tax-deductible basis in the transferred assets, and accordingly, created a temporary difference where the tax basis exceeded the financial statement basis of such intangible assets. As a result, we recognized a deferred tax asset of $1.2 billion on our Consolidated Financial Statements. We expect to be able to realize the deferred tax asset resulting from this intra-entity asset transfer. The impact of the intangible asset transfer from a foreign subsidiary to the United States was not material.

The reconciliation between the federal statutory tax rate applied to income before income taxes and our effective tax rate is summarized as follows:


	Year Ended December 31,
	2021		2020		2019
Federal statutory rate	21.0	%	21.0	%	21.0	%
State taxes, net of federal benefit	2.5	%	4.2	%	0.4	%
Foreign earnings at different rates	(0.3)	%	(10.0)	%	2.5	%
Research and other credits	(1.6)	%	(6.9)	%	(1.9)	%
US tax on foreign earnings	1.1	%	7.2	%	4.3	%
Foreign-derived intangible income deduction	(1.6)	%	(8.0)	%	(3.2)	%
Deferred tax - intra-entity transfer of intangible assets	(0.7)	%	0.6	%	(24.0)	%
Settlement of tax examinations	(0.7)	%	(10.2)	%	(2.4)	%
Acquired IPR&D and related charges	—	%	56.2	%	—	%
Changes in valuation allowance	1.5	%	6.7	%	—	%
Non-taxable unrealized (gain) loss on investment	1.8	%	23.0	%	(5.0)	%
Other	2.1	%	10.9	%	4.3	%
Effective tax rate	25.1	%	94.7	%	(4.0)	%

Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets and liabilities are as follows:


	December 31,
(in millions)	2021		2020
Deferred tax assets:
Net operating loss carryforwards	$	413	$	587
Stock-based compensation	117		113
Reserves and accruals not currently deductible	700		444
Excess of tax basis over book basis of intangible assets	1,157		1,177
Upfront and milestone payments	1,310		1,144
Research and other credit carryforwards	249		219
Equity investments	117		116
Liability related to future royalties	274		247
Other, net	292		311
Total deferred tax assets before valuation allowance	4,629		4,358
Valuation allowance	(520)		(398)
Total deferred tax assets	4,109		3,960
Deferred tax liabilities:
Property, plant and equipment	(227)		(202)
Excess of book basis over tax basis of intangible assets	(6,719)		(6,168)
Other	(180)		(202)
Total deferred tax liabilities	(7,126)		(6,572)
Net deferred tax assets (liabilities)	$	(3,017)	$	(2,612)

The valuation allowance was $520 million and $398 million as of December 31, 2021 and 2020, respectively. The increase of our valuation allowance in 2021 was primarily related to California research and development tax credits.

The valuation allowance was $398 million and $217 million as of December 31, 2020 and 2019, respectively. The increase of our valuation allowance in 2020 was primarily related to acquired attributes related to Forty Seven and Immunomedics acquisitions, and capital losses related to our equity method investments.

As of December 31, 2021, we had U.S. federal net operating loss and tax credit carryforwards of approximately $250 million and $8 million, respectively, which will start to expire in 2022, if not utilized. In addition, we had state net operating loss and tax credit carryforwards of approximately $2.8 billion and $768 million, respectively. The state net operating loss and state tax credit carryforwards will start to expire in 2022 if not utilized.

Utilization of net operating losses and tax credits may be subject to an annual limitation due to ownership change limitations provided in the Internal Revenue Code of 1986, as amended, and similar state provisions. This annual limitation may result in the expiration of the net operating losses and credits before utilization.

We file federal, state and foreign income tax returns in the United States and in many foreign jurisdictions. For federal income tax purposes, the statute of limitations is open for 2016 and onwards and 2013 and onwards for California income tax purposes. For certain acquired entities, the statute of limitations is open for all years from inception due to our utilization of their net operating losses and credits carried over from prior years.

Our income tax returns are subject to audit by federal, state and foreign tax authorities. We are currently under examination by the Internal Revenue Service and Irish tax authorities for our 2016 to 2018 tax years. There are differing interpretations of tax laws and regulations, and as a result, significant disputes may arise with these tax authorities involving issues of the timing and amount of deductions and allocations of income among various tax jurisdictions. We periodically evaluate our exposures associated with our tax filing positions.

Of the total unrecognized tax benefits, $800 million and $1.2 billion as of December 31, 2021 and 2020, respectively, if recognized, would reduce our effective tax rate in the period of recognition. Interest and penalties related to unrecognized tax benefits included income tax expense of $41 million, income tax benefit of $82 million and income tax expense of $105 million on our Consolidated Statements of Income for the years ended December 31, 2021, 2020 and 2019 respectively. Accrued interest and penalties related to unrecognized tax benefits were $218 million and $177 million as of December 31, 2021 and 2020, respectively. As of December 31, 2021, we believe that it is reasonably possible that our unrecognized tax benefits will decrease by approximately $100 million in the next 12 months due to potential settlements with various taxing authorities.

The following is a rollforward of our total gross unrecognized tax benefits:


	Year Ended December 31,
(in millions)	2021		2020		2019
Balance, beginning of period	$	1,614	$	2,031	$	1,595
Tax positions related to current year:
Additions	147		121		138
Reductions	—		—		—
Tax positions related to prior years:
Additions	161		398		405
Reductions	(179)		(481)		—
Settlements	(28)		(454)		(104)
Lapse of statute of limitations	(2)		(1)		(3)
Balance, end of period	$	1,713	$	1,614	$	2,031

In connection with the Tax Cuts and Jobs Act, we recorded a federal income tax payable for transition tax on the mandatory deemed repatriation of foreign earnings that is payable over an eight-year period. As of December 31, 2021 and 2020, we have accrued $4.0 billion and $4.5 billion, respectively, for transition tax. Of the amounts accrued as of December 31, 2021, approximately $473 million is expected to be paid within one year.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32705-109319

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
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-URI http://asc.fasb.org/extlink&oid=6424122&loc=d3e41874-109331

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (SX 210.4-08(h)(2))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

+ Details

Organization and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Basis of Presentation

The accompanying Consolidated Financial Statements include the accounts of Gilead, our wholly-owned subsidiaries and certain variable interest entities for which we are the primary beneficiary. All intercompany transactions have been eliminated. For consolidated entities where we own or are exposed to less than 100% of the economics, we record net income or loss attributable to noncontrolling interests in our Consolidated Statements of Income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties.

We assess whether we are the primary beneficiary of a variable interest entity (“VIE”) at the inception of the arrangement and at each reporting date. This assessment is based on our power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and our obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE.

Segment Information

Segment InformationWe have one operating segment which primarily focuses on the discovery, development and commercialization of innovative medicines in areas of unmet medical need. Our Chief Executive Officer, as the chief operating decision-maker (“CODM”), manages and allocates resources to the operations of our company on an entity-wide basis. Managing and allocating resources on an entity-wide basis enables our CODM to assess the overall level of resources available and how to best deploy these resources across functions and research and development (“R&D”) projects based on unmet medical need and, as necessary, reallocate resources among our internal R&D portfolio and external opportunities to best support the long-term growth of our business.

Significant Accounting Policies, Estimates and Judgments

Significant Accounting Policies, Estimates and Judgments The preparation of these Consolidated Financial Statements in accordance with U.S. generally accepted accounting principles requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses and related disclosures. On an ongoing basis, we evaluate our significant accounting policies and estimates. We base our estimates on historical experience and on various market-specific and other relevant assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Estimates are assessed each period and updated to reflect current information, such as the economic considerations related to the impact that the coronavirus disease (“COVID-19”) could have on our significant accounting estimates. Actual results may differ significantly from these estimates.

Revenue Recognition

Product Sales

We recognize revenue from product sales when control of the product transfers, generally upon shipment or delivery, to the customer, or in certain cases, upon the corresponding sales by our customer to a third party. The revenues are recognized net of estimated government and other rebates and chargebacks, cash discounts for prompt payment, distributor fees, sales return provisions and other related deductions. These deductions to product sales are referred to as gross-to-net deductions and are estimated and recorded in the period in which the related product sales occur. Our payment terms to customers generally range from 30 to 90 days; however, payment terms differ by jurisdiction, by customer and, in some instances, by type of product. Revenues from product sales, net of gross-to-net deductions, are recorded only to the extent a significant reversal in the amount of cumulative revenue recognized is not probable of occurring when the uncertainty associated with gross-to-net deductions is subsequently resolved. Taxes assessed by governmental authorities and collected from customers are excluded from product sales. If we expect, at contract inception, that the period between the transfer of control and corresponding payment from the customer will be one year or less, we do not adjust the amount of consideration for the effects of a financing component.

Gross-to-Net Deductions

Rebates and Chargebacks

Government and other rebates and chargebacks include amounts payable to payers and healthcare providers under various programs, and may vary by product, by payer and individual payer plans. Rebates and chargebacks are based on contractual arrangements or statutory requirements which may vary by product, payer and individual payer plans. For qualified programs that can purchase our products through wholesalers or other distributors at a lower contractual price, the wholesalers or distributors charge back to us the difference between their acquisition cost and the lower contractual price.

Rebates and chargebacks are estimated primarily based on product sales, and expected payer mix and discount rates, which require significant estimates and judgment. Additionally, in developing our estimates, we consider: historical and estimated payer mix; statutory discount requirements and contractual terms; historical claims experience and processing time lags; estimated patient population; known market events or trends; market research; channel inventory data obtained from our major U.S. wholesalers; and other pertinent internal or external information. We assess and update our estimates each reporting period to reflect actual claims and other current information.

Government and other chargebacks that are payable to our direct customers are generally classified as reductions of Accounts receivable on our Consolidated Balance Sheets. Government and other rebates that are payable to third party payers and healthcare providers are recorded in Accrued government and other rebates on our Consolidated Balance Sheets.

Cash Discounts

We estimate cash discounts based on contractual terms, historical customer payment patterns and our expectations regarding future customer payment patterns.

Distributor Fees

Under our inventory management agreements with our significant U.S. wholesalers, we pay the wholesalers a fee primarily for compliance with certain contractually determined covenants such as the maintenance of agreed upon inventory levels. These distributor fees are based on a contractually determined fixed percentage of sales.

Allowance for Sales Returns

Allowances are made for estimated sales returns by our customers and are recorded in the period the related revenue is recognized. We typically permit returns if the product is damaged, defective, or otherwise cannot be used by the customer. In the United States, we typically permit returns six months prior to and up to one year after the product expiration date. Outside the United States, returns are only allowed in certain countries on a limited basis.

Our estimates of sales returns are based primarily on analysis of our historical product return patterns, industry information reporting the return rates for similar products and contractual agreement terms. We also take into consideration known or expected changes in the marketplace specific to each product.

Shipping and Handling

Shipping and handling activities are considered to be fulfillment activities and not considered to be a separate performance obligation.

Royalty, Contract and Other Revenues

Royalty revenue is recognized in the period in which the obligation is satisfied and the corresponding sales by our corporate partners occur.

Research and Development Expenses

R&D expenses consist primarily of clinical studies performed by contract research organizations (“CROs”), materials and supplies, payments under collaborative and other arrangements including milestone payments, licenses and fees, expense reimbursements to the collaboration partners, personnel costs including salaries, benefits and stock-based compensation expense, and overhead allocations consisting of various support and infrastructure costs. Milestone payments made to third-party collaborators are expensed as incurred up to the point of regulatory approval. Milestone payments made upon regulatory approval are capitalized and amortized over the remaining useful life of the related product. From time to time, we enter into development and collaboration agreements in which we share expenses with a collaborative partner. We record payments received from our collaborative partners for their share of the development costs as a reduction of R&D expenses.

We charge R&D costs, including clinical study costs, to expense when incurred. Clinical study costs are a significant component of R&D expenses. Most of our clinical studies are performed by third-party CROs. We monitor levels of performance under each significant contract including the extent of patient enrollment and other activities through communications with our CROs. We accrue costs for clinical studies performed by CROs over the service periods specified in the contracts and adjust our estimates, if required, based upon our ongoing review of the level of effort and costs actually incurred by the CROs. All of our material CRO contracts are terminable by us upon written notice and we are generally only liable for actual services completed by the CRO and certain non-cancelable expenses incurred at any point of termination. Payments we make for R&D services prior to the services being rendered are recorded as prepaid assets in our Consolidated Balance Sheets and are expensed as the services are provided.

Acquired In Process Research and Development Expenses

Acquired In-Process Research and Development ExpensesAcquired IPR&D expenses reflect IPR&D impairments as well as the initial costs of externally developed IPR&D projects, acquired directly in a transaction other than a business combination, that do not have an alternative future use, including upfront payments related to various collaborations and the initial costs of rights to IPR&D projects. The acquired IPR&D is expensed on acquisition date. Future costs to develop these IPR&D projects are recorded in Research and development expenses on our Consolidated Statements of Income as incurred.

Selling, General and Administrative Expenses

Selling, general and administrative (“SG&A”) expenses relate to sales and marketing, finance, human resources, legal and other administrative activities. SG&A expenses consist primarily of personnel costs, facilities and overhead costs, outside marketing, advertising and legal expenses, and other general and administrative costs. SG&A expenses also include the Branded Prescription Drug (“BPD”) fee. In the United States, we, along with other pharmaceutical manufacturers of branded drug products, are required to pay a portion of the BPD fee, which is estimated based on select government sales during the prior year as a percentage of total industry government sales.

We expense the costs of advertising, including promotional expenses, as incurred.

Cash and Cash Equivalents

Cash and Cash Equivalents We consider highly liquid investments with insignificant interest rate risk and an original maturity of three months or less on the purchase date to be cash equivalents.

Marketable and Non-Marketable Securities

Marketable Debt Securities

We determine the appropriate classification of our marketable debt securities at the time of purchase and reevaluate such designation at each balance sheet date. All of our marketable debt securities are considered available-for-sale and carried at estimated fair values and reported in cash equivalents, short-term marketable debt securities or long-term marketable debt securities. Unrealized gains and losses on available-for-sale debt securities are excluded from net income and reported in Accumulated other comprehensive income (loss) (“AOCI”) as a separate component of stockholders’ equity. Other income (expense), net, includes interest, amortization of purchase premiums and discounts, realized gains and losses on sales of securities and expected credit losses, if any. The cost of securities sold is based on the specific identification method. We regularly review our investments for declines in fair value below their amortized cost basis to determine whether the impairment is due to credit-related factors or noncredit-related factors. Our review includes the creditworthiness of the security issuers, the severity of the unrealized losses, whether we have the intent to sell the securities and whether it is more likely than not that we will be required to sell the securities before the recovery of their amortized cost bases. When we determine that a portion of the unrealized loss is due to an expected credit loss, we recognize the loss amount in Other income (expense), net, with a corresponding allowance against the carrying value of the security we hold. The portion of the unrealized loss related to factors other than credit losses is recognized in AOCI.

Marketable and Non-Marketable Equity Securities

Investments in equity securities, other than equity method investments, are recorded at fair market value if fair value is readily determinable, and unrealized gains and losses are included in Other income (expense), net on our Consolidated Statements of Income.

For investments in entities over which we have significant influence but do not meet the requirements for consolidation and have not elected the fair value option, we use the equity method of accounting with our share of the underlying income or loss of such entities reported in Other income (expense), net on our Consolidated Statements of Income. We have elected the fair value option to account for our equity investments in Arcus Biosciences, Inc. (“Arcus”) and Galapagos NV (“Galapagos”) over which we have significant influence. We believe the fair value option best reflects the underlying economics of these investments. See Note 11. Collaborations and Other Arrangements for additional information.

Equity securities without readily determinable fair values are recorded using the measurement alternative of cost less impairment, if any, adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer. Certain investments in equity securities of non-public companies are accounted for using the equity method based on our ownership percentage and other factors that indicate we have significant influence over the investee. See Note 11. Collaborations and Other Arrangements for additional information.

Our investments in equity securities are recorded in Prepaid and other current assets or Other long-term assets on our Consolidated Balance Sheets. We regularly review our securities for indicators of impairment.

Concentrations of Risk

We are subject to credit risk from our portfolio of cash equivalents and marketable securities. Under our investment policy, we limit amounts invested in such securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. We are not exposed to any significant concentrations of credit risk from these financial instruments. The goals of our investment policy, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements; and a competitive after-tax rate of return.

We are also subject to credit risk from our accounts receivable related to our product sales. Trade accounts receivable are recorded net of allowances for wholesaler chargebacks related to government and other programs, cash discounts for prompt payment and credit losses. Estimates of our allowance for credit losses consider a number of factors including existing contractual payment terms, individual customer circumstances, historical payment patterns of our customers, a review of the local economic environment and its potential impact on expected future customer payment patterns and government funding and reimbursement practices. The majority of our trade accounts receivable arises from product sales in the United States and Europe.

Inventories

Inventories are recorded at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis. We periodically review our inventories to identify obsolete, slow-moving, excess or otherwise unsaleable items. If obsolete, slow-moving, excess or unsaleable items are observed and there are no alternate uses for the inventory, we record a write-down to net realizable value through a charge to Cost of goods sold on our Consolidated Statements of Income. The determination of net realizable value requires judgment, including consideration of many factors, such as estimates of future product demand, product net selling prices, current and future market conditions and potential product obsolescence, among others.

When future commercialization is considered probable and the future economic benefit is expected to be realized, based on management’s judgment, we capitalize pre-launch inventory costs prior to regulatory approval. A number of factors are considered, including the current status in the regulatory approval process, potential impediments to the approval process such as safety or efficacy, anticipated R&D initiatives that could impact the indication in which the compound will be used, viability of commercialization and marketplace trends.

Property, Plant and Equipment

Property, plant and equipment is stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method. Repairs and maintenance costs are expensed as incurred. Estimated useful lives in years are generally as follows:


Description			Estimated Useful Life
Buildings and improvements			Shorter of 35 years or useful life
Laboratory and manufacturing equipment			4-10
Office, computer equipment and other			3-15
Leasehold improvements			Shorter of useful life or lease term

Leases

We determine if an arrangement contains a lease at inception. Right-of-use assets and lease liabilities are recognized at the commencement date based on the present value of the lease payments over the lease term, which is the non-cancelable period stated in the contract adjusted for any options to extend or terminate when it is reasonably certain that we will exercise that option. Right-of-use assets are adjusted for prepaid lease payments, lease incentives and initial direct costs incurred. Operating lease expense for the minimum lease payments is recognized on a straight-line basis over the lease term.

We account for lease and nonlease components in our lease agreements as a single lease component in determining lease assets and liabilities. In addition, we do not recognize the right-of-use assets and liabilities for leases with lease terms of one year or less.

As most of our operating leases do not provide an implicit interest rate, we generally utilize a collateralized incremental borrowing rate, applied in a portfolio approach when relevant, based on the information available at the commencement date to determine the lease liability.

Acquisitions

We account for business combinations using the acquisition method of accounting, which generally requires that assets acquired, including IPR&D projects, and liabilities assumed be recorded at their fair values as of the acquisition date on our Consolidated Balance Sheets. Any excess of consideration over the fair value of net assets acquired is recorded as goodwill. The determination of estimated fair value requires us to make significant estimates and assumptions. As a result, we may record adjustments to the fair values of assets acquired and liabilities assumed within the measurement period, which may be up to one year from the acquisition date, with the corresponding offset to goodwill. Transaction costs associated with business combinations are expensed as they are incurred.

When we determine net assets acquired do not meet the definition of a business combination under the acquisition method of accounting, the transaction is accounted for as an acquisition of assets and, therefore, no goodwill is recorded and contingent consideration, such as payments upon achievement of various developmental, regulatory and commercial milestones, generally is not recognized at the acquisition date. In an asset acquisition, upfront payments allocated to IPR&D projects at the acquisition date and subsequent milestone payments are expensed as incurred on our Consolidated Statements of Income unless there is an alternative future use.

Goodwill and Intangible Assets

Goodwill represents the excess of the consideration transferred over the estimated fair value of assets acquired and liabilities assumed in a business combination. Intangible assets are measured at their respective fair values as of the acquisition date and may be subject to adjustment within the measurement period, which may be up to one year from the acquisition date. Intangible assets related to IPR&D projects are considered to be indefinite-lived until the completion or abandonment of the associated R&D efforts. We do not amortize goodwill and intangible assets with indefinite useful lives. Goodwill and indefinite-lived intangible assets are tested for impairment annually or more frequently if events or changes in circumstances indicate that it is more likely than not that the assets are impaired.

When development is successfully completed, which generally occurs when regulatory approval is obtained, the associated assets are deemed finite-lived and amortized over their respective estimated useful lives beginning at that point in time. Intangible assets with finite useful lives are amortized over their estimated useful lives, primarily on a straight-line basis, and are reviewed for impairment when facts or circumstances indicate that the carrying value of these assets may not be recoverable.

Impairment of Long-Lived Assets

Impairment of Long-Lived AssetsLong-lived assets, including property, plant and equipment and finite-lived intangible assets, are reviewed for impairment whenever facts or circumstances either internally or externally may indicate that the carrying value of an asset may not be recoverable. Should there be an indication of impairment, we test for recoverability by comparing the estimated undiscounted future cash flows expected to result from the use of the asset to the carrying amount of the asset or asset group. If the asset or asset group is determined to be impaired, any excess of the carrying value of the asset or asset group over its estimated fair value is recognized as an impairment loss.

Valuation of Contingent Consideration Resulting from a Business Combination and Contingencies

Valuation of Contingent Consideration Resulting from a Business Combination

In connection with certain acquisitions, we may be required to pay future consideration that is contingent upon the achievement of specified development, regulatory approval or sales-based milestone events. We record contingent consideration resulting from a business combination at its fair value on the acquisition date. Each reporting period thereafter, we revalue these obligations and record increases or decreases in their fair value in Research and development expenses on our Consolidated Statements of Income until such time that the related product candidate receives marketing approval.

Increases or decreases in fair value of the contingent consideration liabilities can result from updates to assumptions such as the expected timing or probability of achieving the specified milestones, changes in projected revenues or changes in discount rates. Significant judgment is employed in determining these assumptions as of the acquisition date and for each subsequent period. Updates to assumptions could have a significant impact on our results of operations in any given period. Actual results may differ from estimates.

Contingencies

We are a party to various legal actions. We recognize accruals for such actions to the extent that we conclude that a loss is both probable and reasonably estimable. We accrue the best estimate of loss within a range; however, if no estimate in the range is better than any other, then we accrue the minimum amount in the range. If we determine that a material loss is reasonably possible, we disclose the possible loss or range of loss, or that the amount of loss cannot be estimated at this time.

Foreign Currency Translation, Transaction Gains and Losses, and Hedging Contracts

Non-U.S. entity operations are recorded in the functional currency of each entity. Results of operations for non-U.S. dollar functional currency entities are translated into U.S. dollars using average currency rates. Assets and liabilities are translated using currency rates at period end. Foreign currency translation adjustments are recorded as a component of AOCI within stockholders’ equity. Foreign currency transaction gains and losses are recorded in Other income (expense), net, on our Consolidated Statements of Income. Net foreign currency transaction gains and losses were not material for the years ended December 31, 2021, 2020 and 2019.

We hedge a portion of our foreign currency exposures related to outstanding monetary assets and liabilities as well as forecasted product sales using foreign currency exchange forward contracts. In general, the market risk related to these contracts is offset by corresponding gains and losses on the hedged transactions. The credit risk associated with these contracts is driven by changes in interest and currency exchange rates and, as a result, varies over time. By working only with major banks and closely monitoring current market conditions, we seek to limit the risk that counterparties to these contracts may be unable to perform. We also seek to limit our risk of loss by entering into contracts that permit net settlement at maturity. Therefore, our overall risk of loss in the event of a counterparty default is limited to the amount of any unrealized gains on outstanding contracts (i.e., those contracts that have a positive fair value) at the date of default. We do not enter into derivative contracts for trading purposes.

Fair Value of Financial Instruments

We apply fair value accounting for all financial and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. We define fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities which are required to be recorded at fair value, we consider the principal or most advantageous market in which we would transact and the market-based risk measurements or assumptions that market participants would use in pricing the asset or liability, such as risks inherent in valuation techniques, transfer restrictions and credit risks.

Derivative Financial Instruments

We recognize all derivative instruments as either assets or liabilities at fair value on our Consolidated Balance Sheets. Unrealized changes in the fair value of derivatives designated as part of a hedge transaction are recorded in AOCI. The unrealized gains or losses in AOCI are reclassified into Product sales on our Consolidated Statements of Income when the respective hedged transactions affect earnings. Changes in the fair value of derivatives that are not part of a hedge transaction are recorded each period in Other income (expense), net on our Consolidated Statements of Income.

We assess, both at inception and on an ongoing basis, whether the derivatives that are used in hedging transactions are effective in offsetting the changes in cash flows or fair values of the hedged items. If we determine that a forecasted transaction is probable of not occurring, we discontinue hedge accounting for the affected portion of the hedge instrument, and any related unrealized gain or loss on the contract is recognized in Other income (expense), net on our Consolidated Statements of Income.

Share-Based Compensation

Share-Based CompensationWe provide share-based compensation in the form of various types of equity-based awards, including restricted stock units (“RSU”s), performance share awards or units (“PSU”s) and stock options. Compensation expense is recognized on the Consolidated Statements of Income based on the estimated fair value of the award on the grant date. The estimated fair value of RSUs is based on the closing price of our common stock. For PSUs, depending on the terms of the award, fair value on the date of grant is determined based on either the Monte Carlo valuation methodology or the closing stock price on the date of grant. For stock option awards, estimated fair value is based on the Black-Scholes option valuation model.

Income Taxes

Our income tax provision is computed under the liability method. Deferred tax assets and liabilities are determined based on the difference between the financial statement and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. Significant estimates are required in determining our provision for income taxes. Some of these estimates are based on interpretations of applicable tax laws or regulations.

We recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by tax authorities based on the technical merits of the position. The tax benefit recognized in the Consolidated Financial Statements for a particular tax position is based on the largest benefit that is more likely than not to be realized. The amount of unrecognized tax benefits (“UTB”) is adjusted as appropriate for changes in facts and circumstances, such as significant amendments to existing tax law, new regulations or interpretations by tax authorities, new information obtained during a tax examination or resolution of an examination. We recognize both accrued interest and penalties, where appropriate, related to UTB in Income tax (expense) benefit on our Consolidated Statements of Income.

We have elected to account for the tax on Global Intangible Low-Taxed Income, enacted as part of the Tax Cuts and Jobs Act, as a component of tax expense in the period in which the tax is incurred.

Organization and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Accounting Policies [Abstract]

Property, Plant and Equipment, Estimated Useful Life

Estimated useful lives in years are generally as follows:


Description			Estimated Useful Life
Buildings and improvements			Shorter of 35 years or useful life
Laboratory and manufacturing equipment			4-10
Office, computer equipment and other			3-15
Leasehold improvements			Shorter of useful life or lease term

Revenues (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

Revenues were as follows:


	Year Ended December 31, 2021								Year Ended December 31, 2020								Year Ended December 31, 2019
(in millions)	U.S.		Europe		Other International		Total		U.S.		Europe		Other International		Total		U.S.		Europe		Other International		Total
Product Sales:
HIV
Atripla	$	121	$	12	$	12	$	145	$	307	$	21	$	21	$	349	$	501	$	60	$	39	$	600
Biktarvy	7,049		969		606		8,624		6,095		735		429		7,259		4,225		370		143		4,738
Complera/Eviplera	102		142		14		258		89		159		21		269		160		214		32		406
Descovy	1,397		164		139		1,700		1,526		197		138		1,861		1,078		255		167		1,500
Genvoya	2,267		391		221		2,879		2,605		490		243		3,338		2,984		664		283		3,931
Odefsey	1,076		440		52		1,568		1,172		450		50		1,672		1,180		438		37		1,655
Stribild	132		43		14		189		125		54		17		196		268		75		26		369
Truvada	314		22		35		371		1,376		27		45		1,448		2,640		101		72		2,813
Revenue share - Symtuza(1)	355		165		11		531		331		149		8		488		249		130		—		379
Other HIV(2)	15		18		17		50		25		5		28		58		30		5		12		47
Total HIV	12,828		2,366		1,121		16,315		13,651		2,287		1,000		16,938		13,315		2,312		811		16,438

Veklury	3,640		1,095		830		5,565		2,026		607		178		2,811		—		—		—		—

Hepatitis C virus (“HCV”)
Ledipasvir/ Sofosbuvir(3)	84		31		97		212		92		29		151		272		312		71		260		643
Sofosbuvir/Velpatasvir(4)	815		316		331		1,462		864		337		398		1,599		971		553		441		1,965
Other HCV(5)	119		74		14		207		132		48		13		193		182		118		28		328
Total HCV	1,018		421		442		1,881		1,088		414		562		2,064		1,465		742		729		2,936

Hepatitis B virus (“HBV”) / Hepatitis Delta virus (“HDV”)
Vemlidy	384		34		396		814		356		29		272		657		309		21		158		488
Viread	11		28		72		111		14		34		137		185		32		69		142		243
Other HBV/HDV(6)	2		42		—		44		10		8		—		18		2		9		—		11
Total HBV/HDV	397		104		468		969		380		71		409		860		343		99		300		742

Cell Therapy
Tecartus	136		40		—		176		34		10		—		44		—		—		—		—
Yescarta	406		253		36		695		362		191		10		563		373		83		—		456
Total Cell Therapy	542		293		36		871		396		201		10		607		373		83		—		456

Trodelvy	370		10		—		380		49		—		—		49		—		—		—		—

Other
AmBisome	39		274		227		540		61		230		145		436		37		234		136		407
Letairis	206		—		—		206		314		—		—		314		618		—		—		618
Ranexa	10		—		—		10		9		—		—		9		216		—		—		216
Zydelig	26		35		1		62		31		39		2		72		47		54		2		103
Other(7)	100		80		29		209		136		45		14		195		151		43		9		203
Total Other	381		389		257		1,027		551		314		161		1,026		1,069		331		147		1,547
Total product sales	19,176		4,678		3,154		27,008		18,141		3,894		2,320		24,355		16,565		3,567		1,987		22,119
Royalty, contract and other revenues	91		196		10		297		76		241		17		334		80		244		6		330
Total revenues	$	19,267	$	4,874	$	3,164	$	27,305	$	18,217	$	4,135	$	2,337	$	24,689	$	16,645	$	3,811	$	1,993	$	22,449

_______________________________

(1) Represents our revenue from cobicistat (“C”), emtricitabine (“FTC”) and tenofovir alafenamide (“TAF”) in Symtuza (darunavir/C/FTC/TAF), a fixed dose combination product commercialized by Janssen Sciences Ireland Unlimited Company (“Janssen”).

(2) Includes Emtriva and Tybost.

(3) Amounts consist of sales of Harvoni and the authorized generic version of Harvoni sold by our separate subsidiary, Asegua Therapeutics LLC.

(4) Amounts consist of sales of Epclusa and the authorized generic version of Epclusa sold by our separate subsidiary, Asegua Therapeutics LLC.

(5) Includes Vosevi and Sovaldi.

(6) Includes Hepcludex and Hepsera.

(7) Includes Cayston and Jyseleca.

Summarized Revenues from Major Customers

The following table summarizes revenues from each of our customers who individually accounted for 10% or more of our total revenues:


	Year Ended December 31,
(as a percentage of total revenues)	2021		2020		2019
AmerisourceBergen Corporation	23	%	27	%	21	%
Cardinal Health, Inc.	22	%	21	%	21	%
McKesson Corporation	20	%	20	%	22	%

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities Measured at Fair Value

The following table summarizes the types of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy:


	December 31, 2021								December 31, 2020
(in millions)	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Available-for-sale debt securities:
U.S. treasury securities	$	407	$	—	$	—	$	407	$	309	$	—	$	—	$	309
U.S. government agencies securities	—		4		—		4		—		—		—		—
Non-U.S. government securities	—		50		—		50		—		43		—		43
Certificates of deposit	—		249		—		249		—		216		—		216
Corporate debt securities	—		1,363		—		1,363		—		1,142		—		1,142
Residential mortgage and asset-backed securities	—		424		—		424		—		316		—		316
Equity securities:
Money market funds	3,661		—		—		3,661		4,361		—		—		4,361
Equity investment in Galapagos(1)	931		—		—		931		1,648		—		—		1,648
Equity investment in Arcus(1)	559		—		—		559		212		—		—		212
Other publicly traded equity securities	331		—		—		331		531		—		—		531
Deferred compensation plan	261		—		—		261		218		—		—		218
Foreign currency derivative contracts	—		80		—		80		—		12		—		12
Total	$	6,150	$	2,170	$	—	$	8,320	$	7,279	$	1,729	$	—	$	9,008
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	$	—	$	—	$	317	$	317	$	—	$	—	$	—	$	—
Deferred compensation plan	261		—		—		261		218		—		—		218
Foreign currency derivative contracts	—		5		—		5		—		121		—		121
Total	$	261	$	5	$	317	$	583	$	218	$	121	$	—	$	339

_______________________________

(1) See Note 11. Collaborations and Other Arrangements for additional information.

Summary of Classification of Other Equity Securities

The following table summarizes the classification of our equity securities measured at fair value on a recurring basis on our Consolidated Balance Sheets:


(in millions)	December 31, 2021		December 31, 2020
Cash and cash equivalents	$	3,661	$	4,361
Prepaid and other current assets	885		853
Other long-term assets	1,197		1,756
Total	$	5,743	$	6,970

Available-for-Sale Debt Securities (Tables)

12 Months Ended

Dec. 31, 2021

Debt Securities, Available-for-sale [Abstract]

Summary of Available-for-Sale Debt Securities at Estimated Fair Value

The following table summarizes our available-for-sale debt securities:


	December 31, 2021								December 31, 2020
(in millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. treasury securities	$	408	$	—	$	(1)	$	407	$	308	$	1	$	—	$	309
U.S. government agencies securities	4		—		—		4		—		—		—		—
Non-U.S. government securities	50		—		—		50		43		—		—		43
Certificates of deposit	249		—		—		249		216		—		—		216
Corporate debt securities	1,365		—		(2)		1,363		1,140		2		—		1,142
Residential mortgage and asset-backed securities	425		—		(1)		424		316		—		—		316
Total	$	2,501	$	—	$	(4)	$	2,497	$	2,023	$	3	$	—	$	2,026

Summary of the Classification of Available-for-Sale Debt Securities

The following table summarizes the classification of our available-for-sale debt securities in our Consolidated Balance Sheets:


(in millions)	December 31, 2021		December 31, 2020
Cash and cash equivalents	$	6	$	113
Short-term marketable debt securities	1,182		1,411
Long-term marketable debt securities	1,309		502
Total	$	2,497	$	2,026

Summary of Available-for-Sale Debt Securities by Contractual Maturity

The following table summarizes our available-for-sale debt securities by contractual maturity:


	December 31, 2021
(in millions)	Amortized Cost		Fair Value
Within one year	$	1,189	$	1,188
After one year through five years	1,288		1,286
After five years	24		23
Total	$	2,501	$	2,497

Derivative Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2021

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Summary of Classification and Fair Value of Derivative Instruments

The following table summarizes the classification and fair values of derivative instruments in our Consolidated Balance Sheets:


	December 31, 2021
	Derivative Assets			Derivative Liabilities
(in millions)	Classification	Fair Value		Classification	Fair Value
Derivatives designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	$	75	Accrued and other current liabilities	$	4
Foreign currency exchange contracts	Other long-term assets	5		Other long-term obligations	1
Total derivatives designated as hedges		80			5
Derivatives not designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	—		Accrued and other current liabilities	—
Total derivatives not designated as hedges		—			—
Total derivatives		$	80		$	5


	December 31, 2020
	Derivative Assets			Derivative Liabilities
(in millions)	Classification	Fair Value		Classification	Fair Value
Derivatives designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	$	—	Accrued and other current liabilities	$	113
Foreign currency exchange contracts	Other long-term assets	—		Other long-term obligations	7
Total derivatives designated as hedges		—			120
Derivatives not designated as hedges:
Foreign currency exchange contracts	Prepaid and other current assets	12		Accrued and other current liabilities	1
Total derivatives not designated as hedges		12			1
Total derivatives		$	12		$	121

Summary of Effect of Foreign Currency Exchange Contracts

The following table summarizes the effect of our foreign currency exchange contracts on our Consolidated Financial Statements:


	Year Ended December 31,
(in millions)	2021		2020		2019
Derivatives designated as hedges:
Gain (loss) recognized in AOCI	$	147	$	(118)	$	76
Gain (loss) reclassified from AOCI into Product sales	$	(67)	$	47	$	127
Derivatives not designated as hedges:
Gain (loss) recognized in Other income (expense), net	$	21	$	(51)	$	22

Summary of Potential Effect of Offsetting Derivatives

The following table summarizes the potential effect of offsetting our foreign currency exchange contracts on our Consolidated Balance Sheets:


							Gross Amounts Not Offset on the Consolidated Balance Sheets
(in millions)	Gross Amounts of Recognized Assets/Liabilities		Gross Amounts Offset on the Consolidated Balance Sheets		Amounts of Assets/Liabilities Presented on the Consolidated Balance Sheets		Derivative Financial Instruments		Cash Collateral Received/Pledged		Net Amount (Legal Offset)
As of December 31, 2021
Derivative assets	$	80	$	—	$	80	$	(4)	$	—	$	76
Derivative liabilities	$	5	$	—	$	5	$	(4)	$	—	$	1
As of December 31, 2020
Derivative assets	$	12	$	—	$	12	$	(12)	$	—	$	—
Derivative liabilities	$	121	$	—	$	121	$	(12)	$	—	$	109

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

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-Publisher FASB
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-Section 50
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Acquisitions (Tables)

12 Months Ended

Dec. 31, 2021

Business Combination and Asset Acquisition [Abstract]

Summarized Fair Values of Assets Acquired and Liabilities Assumed

The following table summarizes estimated fair values of assets acquired and liabilities assumed as of the acquisition date:


(in millions)	Amount
Intangible assets:
Finite-lived intangible asset	$	845
Acquired IPR&D	1,190
Deferred income taxes, net	(513)
Other assets (and liabilities), net	(187)
Total identifiable net assets	1,335
Goodwill	226
Total consideration	$	1,561

The following table summarizes fair values of assets acquired and liabilities assumed as of the acquisition date:


(in millions)	Amount
Cash and cash equivalents	$	726
Inventories	946
Intangible assets:
Finite-lived intangible asset	4,600
Acquired IPR&D	15,760
Outlicense contract	175
Deferred tax liabilities	(4,565)
Liability related to future royalties	(1,100)
Other assets (and liabilities), net	64
Total identifiable net assets	16,606
Goodwill	3,991
Total consideration transferred	$	20,597

Inventories (Tables)

12 Months Ended

Dec. 31, 2021

Inventory Disclosure [Abstract]

Schedule of Inventories

The following table summarizes our Inventories:


	December 31,
(in millions)	2021		2020
Raw materials	$	1,112	$	1,080
Work in process	590		976
Finished goods	1,032		958
Total	$	2,734	$	3,014

Reported as:
Inventories	$	1,618	$	1,683
Other long-term assets	1,116		1,331
Total	$	2,734	$	3,014

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

The following table summarizes our Property, plant and equipment, net:


	December 31,
(in millions)	2021		2020
Land and land improvements	$	404	$	404
Buildings and improvements (including leasehold improvements)	3,794		3,678
Laboratory and manufacturing equipment	952		904
Office, computer equipment and other	807		793
Construction in progress	1,057		856
Subtotal	7,014		6,635
Less: accumulated depreciation and amortization	1,893		1,668
Total	$	5,121	$	4,967

Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2021

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

The following table summarizes the changes in the carrying amount of Goodwill:


	December 31,
(in millions)	2021		2020
Beginning balance	$	8,108	$	4,117
Goodwill resulting from acquisitions	226		3,991
Measurement period adjustments	(2)		—
Ending balance	$	8,332	$	8,108

Indefinite-Lived Intangible Assets

The following table summarizes our Intangible assets, net:


	December 31, 2021								December 31, 2020
(in millions)	Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount
Finite-lived assets
Intangible asset - sofosbuvir	$	10,720	$	(5,651)	$	—	$	5,069	$	10,720	$	(4,952)	$	—	$	5,768
Intangible asset - axicabtagene ciloleucel(1)	7,110		(1,501)		—		5,609		6,200		(1,105)		—		5,095
Intangible asset - Trodelvy(2)	5,630		(507)		—		5,123		4,600		(63)		—		4,537
Intangible asset - Hepcludex	845		(72)		—		773		—		—		—		—
Other(3)	1,610		(650)		1		961		1,377		(540)		(1)		836
Total finite-lived assets	25,915		(8,381)		1		17,535		22,897		(6,660)		(1)		16,236
Indefinite-lived assets - IPR&D(4)	15,920		—		—		15,920		16,890		—		—		16,890
Total intangible assets	$	41,835	$	(8,381)	$	1	$	33,455	$	39,787	$	(6,660)	$	(1)	$	33,126

________________________________

(1) Gross carrying amount as of December 31, 2021 includes $910 million reclassified in the first quarter of 2021 from indefinite-lived assets - IPR&D following the March 2021 FDA approval of Yescarta for the treatment of adult patients with relapsed or refractory follicular lymphoma.

(2) Gross carrying amount as of December 31, 2021 includes Trodelvy for metastatic TNBC and Trodelvy for use in adult patients with locally advanced or metastatic UC. The amount related to UC of $1.0 billion was reclassified to finite-lived assets from indefinite-lived assets - IPR&D upon the accelerated approval by FDA in April 2021.

(3) In October 2021, FDA granted approval of Tecartus for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia. Accordingly, the related amount of $200 million was reclassified to finite-lived assets in the fourth quarter of 2021.

(4) Gross carrying amount as of December 31, 2021 includes IPR&D from our 2021 acquisition of MYR and remaining IPR&D from our 2020 acquisition of Immunomedics. Gross carrying amount as of December 31, 2020 includes IPR&D from our 2020 acquisition of Immunomedics and remaining IPR&D from our 2017 acquisition of Kite.

Finite-Lived Intangible Assets

The following table summarizes our Intangible assets, net:


	December 31, 2021								December 31, 2020
(in millions)	Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization		Foreign Currency Translation Adjustment		Net Carrying Amount
Finite-lived assets
Intangible asset - sofosbuvir	$	10,720	$	(5,651)	$	—	$	5,069	$	10,720	$	(4,952)	$	—	$	5,768
Intangible asset - axicabtagene ciloleucel(1)	7,110		(1,501)		—		5,609		6,200		(1,105)		—		5,095
Intangible asset - Trodelvy(2)	5,630		(507)		—		5,123		4,600		(63)		—		4,537
Intangible asset - Hepcludex	845		(72)		—		773		—		—		—		—
Other(3)	1,610		(650)		1		961		1,377		(540)		(1)		836
Total finite-lived assets	25,915		(8,381)		1		17,535		22,897		(6,660)		(1)		16,236
Indefinite-lived assets - IPR&D(4)	15,920		—		—		15,920		16,890		—		—		16,890
Total intangible assets	$	41,835	$	(8,381)	$	1	$	33,455	$	39,787	$	(6,660)	$	(1)	$	33,126

________________________________

(1) Gross carrying amount as of December 31, 2021 includes $910 million reclassified in the first quarter of 2021 from indefinite-lived assets - IPR&D following the March 2021 FDA approval of Yescarta for the treatment of adult patients with relapsed or refractory follicular lymphoma.

(2) Gross carrying amount as of December 31, 2021 includes Trodelvy for metastatic TNBC and Trodelvy for use in adult patients with locally advanced or metastatic UC. The amount related to UC of $1.0 billion was reclassified to finite-lived assets from indefinite-lived assets - IPR&D upon the accelerated approval by FDA in April 2021.

(3) In October 2021, FDA granted approval of Tecartus for the treatment of adult patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia. Accordingly, the related amount of $200 million was reclassified to finite-lived assets in the fourth quarter of 2021.

(4) Gross carrying amount as of December 31, 2021 includes IPR&D from our 2021 acquisition of MYR and remaining IPR&D from our 2020 acquisition of Immunomedics. Gross carrying amount as of December 31, 2020 includes IPR&D from our 2020 acquisition of Immunomedics and remaining IPR&D from our 2017 acquisition of Kite.

Estimated Future Amortization Expense of Finite-Lived Intangible Assets

The following table summarizes the estimated future amortization expense associated with our finite-lived intangible assets as of December 31, 2021:


(in millions)	Amount
2022	$	1,778
2023	1,778
2024	1,778
2025	1,773
2026	1,765
Thereafter	8,663
Total	$	17,535

Other Financial Information (Tables)

12 Months Ended

Dec. 31, 2021

Other Financial Information [Abstract]

Accounts Receivable, net

The following table summarizes our Accounts receivable, net:


	December 31,
(in millions)	2021		2020
Accounts receivable	$	5,278	$	5,560
Less: chargebacks	671		552
Less: cash discounts and other	67		72
Less: allowances for credit losses	47		44
Accounts receivable, net	$	4,493	$	4,892

Other Accrued Liabilities

The following table summarizes the components of Accrued and other current liabilities:


	December 31,
(in millions)	2021		2020
Compensation and employee benefits	$	927	$	864
Income taxes payable	539		598
Allowance for sales returns	499		587
Accrual for settlement related to bictegravir litigation(1)	1,250		—
Other accrued liabilities	2,930		2,287
Accrued and other current liabilities	$	6,145	$	4,336

_______________________________

(1) See Note 14. Commitments and Contingencies for additional information.

Debt and Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Summary of Financing Arrangements

The following table summarizes the carrying amount of our borrowings under various financing arrangements:


(in millions)				December 31,
Type of Borrowing	Issue Date	Due Date	Interest Rate	2021		2020
Senior Unsecured	March 2011	April 2021	4.50%	$	—	$	1,000
Senior Unsecured	September 2020	September 2021	3-month LIBOR + 0.15%	—		499
Senior Unsecured	December 2011	December 2021	4.40%	—		1,249
Senior Unsecured	September 2016	March 2022	1.95%	500		499
Senior Unsecured	September 2015	September 2022	3.25%	999		998
Senior Unsecured	September 2016	September 2023	2.50%	748		748
Senior Unsecured	September 2020	September 2023	3-month LIBOR + 0.52%	—		498
Senior Unsecured	September 2020	September 2023	0.75%	1,496		1,992
Term Loan	October 2020	October 2023	variable	—		998
Senior Unsecured	March 2014	April 2024	3.70%	1,747		1,746
Senior Unsecured	November 2014	February 2025	3.50%	1,747		1,746
Senior Unsecured	September 2015	March 2026	3.65%	2,739		2,737
Senior Unsecured	September 2016	March 2027	2.95%	1,247		1,246
Senior Unsecured	September 2020	October 2027	1.20%	746		745
Senior Unsecured	September 2020	October 2030	1.65%	993		992
Senior Unsecured	September 2015	September 2035	4.60%	992		991
Senior Unsecured	September 2016	September 2036	4.00%	742		741
Senior Unsecured	September 2020	October 2040	2.60%	987		986
Senior Unsecured	December 2011	December 2041	5.65%	996		996
Senior Unsecured	March 2014	April 2044	4.80%	1,736		1,735
Senior Unsecured	November 2014	February 2045	4.50%	1,733		1,732
Senior Unsecured	September 2015	March 2046	4.75%	2,220		2,219
Senior Unsecured	September 2016	March 2047	4.15%	1,727		1,726
Senior Unsecured	September 2020	October 2050	2.80%	1,476		1,476
Total senior unsecured notes and term loan facility				25,571		30,295
Liability related to future royalties				1,124		1,107
Total debt, net				26,695		31,402
Less: current portion of long-term debt and other obligations, net				1,516		2,757
Total long-term debt, net				$	25,179	$	28,645

Schedule of Contractual Maturities of Financing Obligations

The following table summarizes the aggregate future principal maturities of our senior unsecured notes as of December 31, 2021:


(in millions)	Amount
2022	$	1,500
2023	2,250
2024	1,750
2025	1,750
2026	2,750
Thereafter	15,750
Total	$	25,750

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

Leases (Tables)

12 Months Ended

Dec. 31, 2021

Leases [Abstract]

Supplemental Information Related to Operating Leases

The following table summarizes balance sheet and other information related to our operating leases:


		December 31,
(in millions, except weighted average amounts)	Classification	2021			2020
Right-of-use assets, net	Other long-term assets	$	542		$	646
Lease liabilities - current	Accrued and other current liabilities	$	101		$	107
Lease liabilities - noncurrent	Other long-term obligations	$	489		$	608
Weighted average remaining lease term		8.5 years			8.6 years
Weighted average discount rate		3.00		%	3.32		%

The following table summarizes other supplemental information related to our operating leases:


	Year Ended December 31,
(in millions)	2021		2020
Cash paid for amounts included in the measurement of lease liabilities	$	123	$	66
Right-of-use assets obtained in exchange for lease liabilities	$	88	$	88

Operating Lease Aggregate Future Lease Payments

The following table summarizes a maturity analysis of our operating lease liabilities showing the aggregate lease payments as of December 31, 2021:


(in millions)	Amount
2022	$	117
2023	108
2024	92
2025	61
2026	50
Thereafter	249
Total undiscounted lease payments	677
Less: imputed interest	87
Total discounted lease payments	$	590

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Stockholders' Equity Note [Abstract]

Schedule of Stock Repurchases

The following table summarizes our stock repurchases under the 2016 Program:


	Year Ended December 31,
(in millions, except per share amounts)	2021		2020		2019
Shares repurchased and retired	8		22		26
Amount	$	546	$	1,583	$	1,749
Average price per share	$	66.58	$	70.64	$	66.36

Schedule of Dividends Declared

The following table summarizes cash dividends declared on our common stock:


	2021				2020
(in millions, except per share amounts)	Dividend Per Share		Amount		Dividend Per Share		Amount
First quarter	$	0.71	$	906	$	0.68	$	867
Second quarter	0.71		903		0.68		866
Third quarter	0.71		905		0.68		866
Fourth quarter	0.71		904		0.68		865
Total	$	2.84	$	3,618	$	2.72	$	3,464

Schedule of Accumulated OCI by Component

The following table summarizes the changes in AOCI by component, net of tax:


(in millions)	Foreign Currency Translation, Net of Tax		Unrealized Gains and Losses on Available-for-Sale Debt Securities, Net of Tax		Unrealized Gains and Losses on Cash Flow Hedges, Net of Tax		Total
Balance as of December 31, 2018	$	47	$	(52)	$	85	$	80
Net unrealized gain	6		54		72		132
Reclassifications to net income	—		(1)		(126)		(127)
Net current period other comprehensive income (loss)	6		53		(54)		5
Balance as of December 31, 2019	$	53	$	1	$	31	$	85
Net unrealized gain (loss)	(2)		43		(103)		(62)
Reclassifications to net income	—		(42)		(41)		(83)
Net current period other comprehensive income (loss)	(2)		1		(144)		(145)
Balance as of December 31, 2020	$	51	$	2	$	(113)	$	(60)
Net unrealized gain (loss)	$	(38)	$	(6)	$	129	$	85
Reclassifications to net income	—		—		58		58
Net current period other comprehensive income (loss)	(38)		(6)		187		143
Balance as of December 31, 2021	$	13	$	(4)	$	74	$	83

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

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+ Details

Employee Benefits (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Activity Under Stock Option Plans

The following table summarizes activity and related information under our stock option plans. All option grants presented in the table had exercise prices not less than the fair value of the underlying common stock on the grant date:


	Shares (in millions)	Weighted- Average Exercise Price (in dollars)		Weighted-Average Remaining Contractual Term (years)	Aggregate Intrinsic Value (in millions)
Outstanding as of December 31, 2020	16.6	$	69.40
Granted	3.8	$	64.77
Forfeited	(0.9)	$	67.67
Expired	(1.1)	$	82.11
Exercised	(1.6)	$	37.46
Outstanding as of December 31, 2021	16.8	$	70.60	5.34	$	101
Exercisable as of December 31, 2021	11.2	$	72.43	3.67	$	68
Expected to vest, net of estimated forfeitures as of December 31, 2021	5.3	$	67.01	8.61	$	32

RSU and PSU Activity

The following table summarizes our RSU and PSU activity and related information:


	RSUs			PSUs
(in millions, except per share amounts)	Shares	Weighted- Average Grant Date Fair Value Per Share		Shares(1)	Weighted- Average Grant Date Fair Value Per Share(1)
Outstanding as of December 31, 2020	19.5	$	69.80	0.6	$	84.87
Granted	11.9	$	65.42	0.3	$	71.31
Vested	(7.0)	$	70.30	(0.1)	$	88.36
Forfeited	(3.5)	$	67.77	(0.1)	$	78.37
Outstanding as of December 31, 2021	20.9	$	67.48	0.7	$	79.13

________________________________

(1) Weighted-average grant-date fair value per share excludes shares related to grants that currently have no grant date as the performance objectives have not yet been defined.

Stock-based Compensation Expenses -Included in Consolidated Statement of Income

The following table summarizes total stock-based compensation expenses included on our Consolidated Statements of Income:


	Year Ended December 31,
(in millions)	2021		2020		2019
Cost of goods sold	$	40	$	109	$	48
Research and development expenses	287		462		289
Selling, general and administrative expenses	308		505		299
Stock-based compensation expense included in total costs and expenses(1)	635		1,076		636
Income tax effect(2)	(100)		(222)		2
Stock-based compensation expense, net of tax	$	535	$	854	$	638

________________________________

(1) Pre-tax stock-based compensation expense for the year ended December 31, 2020 of $1.1 billion included $643 million non-cash stock-based expense and $289 million and $144 million of accelerated post-acquisition stock-based expense related to the acquisitions of Immunomedics and Forty Seven, respectively. See Note 6. Acquisitions for additional information.

(2) Income tax effect for the year ended December 31, 2019 included a $114 million income tax expense following the U.S. Court of Appeals decision in Altera Corp v. Commissioner, which requires related parties in an intercompany cost sharing arrangement to share expenses related to stock-based compensation.

Schedule of Assumptions to Calculate the Estimated Fair Value of Awards

We used the following assumptions to calculate the estimated fair value of the awards:


	Year Ended December 31,
	2021		2020		2019
Expected volatility:
Stock options	29	%	29	%	27	%
ESPP	25	%	28	%	27	%
Expected term in years:
Stock options	5.0		5.0		5.5
ESPP	0.5		0.5		0.5
Risk-free interest rate:
Stock options	0.8	%	0.8	%	2.3	%
ESPP	0.1	%	0.6	%	1.8	%
Expected dividend yield	4.4	%	4.0	%	3.6	%

Net Income Per Share Attributable to Gilead Common Shareholders (Tables)

12 Months Ended

Dec. 31, 2021

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table shows the calculation of basic and diluted net income per share attributable to Gilead common stockholders:


	Year Ended December 31,
(in millions, except per share amounts)	2021		2020		2019
Net income attributable to Gilead	$	6,225	$	123	$	5,386
Shares used in per share calculation - basic	1,256		1,257		1,270
Dilutive effect of stock options and equivalents	6		6		7
Shares used in per share calculation - diluted	1,262		1,263		1,277
Net income per share attributable to Gilead common stockholders - basic	$	4.96	$	0.10	$	4.24
Net income per share attributable to Gilead common stockholders - diluted	$	4.93	$	0.10	$	4.22

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2021

Income Tax Disclosure [Abstract]

Schedule of Income (Loss) Before Income Taxes

Income before income taxes consists of the following:


	Year Ended December 31,
(in millions)	2021		2020		2019
Domestic	$	8,587	$	2,505	$	4,112
Foreign	(309)		(836)		1,048
Income before income taxes	$	8,278	$	1,669	$	5,160

Schedule of Income Tax Expense (Benefit)

The Income tax (expense) benefit consists of the following:


	Year Ended December 31,
(in millions)	2021		2020		2019
Federal:
Current	$	(1,776)	$	(1,450)	$	(1,646)
Deferred	250		164		843
	(1,526)		(1,286)		(803)
State:
Current	(228)		(198)		(135)
Deferred	(185)		97		42
	(413)		(101)		(93)
Foreign:
Current	(185)		(155)		(124)
Deferred	47		(38)		1,224
	(138)		(193)		1,100
Income tax (expense) benefit	$	(2,077)	$	(1,580)	$	204

Schedule of Difference Between Provision for Income Taxes and Federal Statutory Income Tax Rate to Income Before Provision for Income Taxes

The reconciliation between the federal statutory tax rate applied to income before income taxes and our effective tax rate is summarized as follows:


	Year Ended December 31,
	2021		2020		2019
Federal statutory rate	21.0	%	21.0	%	21.0	%
State taxes, net of federal benefit	2.5	%	4.2	%	0.4	%
Foreign earnings at different rates	(0.3)	%	(10.0)	%	2.5	%
Research and other credits	(1.6)	%	(6.9)	%	(1.9)	%
US tax on foreign earnings	1.1	%	7.2	%	4.3	%
Foreign-derived intangible income deduction	(1.6)	%	(8.0)	%	(3.2)	%
Deferred tax - intra-entity transfer of intangible assets	(0.7)	%	0.6	%	(24.0)	%
Settlement of tax examinations	(0.7)	%	(10.2)	%	(2.4)	%
Acquired IPR&D and related charges	—	%	56.2	%	—	%
Changes in valuation allowance	1.5	%	6.7	%	—	%
Non-taxable unrealized (gain) loss on investment	1.8	%	23.0	%	(5.0)	%
Other	2.1	%	10.9	%	4.3	%
Effective tax rate	25.1	%	94.7	%	(4.0)	%

Schedule of Deferred Tax Assets and Liabilities

Significant components of our deferred tax assets and liabilities are as follows:


	December 31,
(in millions)	2021		2020
Deferred tax assets:
Net operating loss carryforwards	$	413	$	587
Stock-based compensation	117		113
Reserves and accruals not currently deductible	700		444
Excess of tax basis over book basis of intangible assets	1,157		1,177
Upfront and milestone payments	1,310		1,144
Research and other credit carryforwards	249		219
Equity investments	117		116
Liability related to future royalties	274		247
Other, net	292		311
Total deferred tax assets before valuation allowance	4,629		4,358
Valuation allowance	(520)		(398)
Total deferred tax assets	4,109		3,960
Deferred tax liabilities:
Property, plant and equipment	(227)		(202)
Excess of book basis over tax basis of intangible assets	(6,719)		(6,168)
Other	(180)		(202)
Total deferred tax liabilities	(7,126)		(6,572)
Net deferred tax assets (liabilities)	$	(3,017)	$	(2,612)

Schedule of Unrecognized Tax Benefits Roll Forward

The following is a rollforward of our total gross unrecognized tax benefits:


	Year Ended December 31,
(in millions)	2021		2020		2019
Balance, beginning of period	$	1,614	$	2,031	$	1,595
Tax positions related to current year:
Additions	147		121		138
Reductions	—		—		—
Tax positions related to prior years:
Additions	161		398		405
Reductions	(179)		(481)		—
Settlements	(28)		(454)		(104)
Lapse of statute of limitations	(2)		(1)		(3)
Balance, end of period	$	1,713	$	1,614	$	2,031

Organization and Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) segment country	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of countries in which entity operates \| country	35
Number of operating segments \| segment	1
Advertising expense	$ 735,000,000	$ 795,000,000	$ 784,000,000
Write-offs charged against allowance	$ 0	$ 0	$ 0
Buildings and improvements
Organization And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	35 years
Minimum \| Laboratory and manufacturing equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	4 years
Minimum \| Office, computer equipment and other
Organization And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Maximum \| Laboratory and manufacturing equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	10 years
Maximum \| Office, computer equipment and other
Organization And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	15 years

Revenues - Disaggregation of Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 27,305	$ 24,689	$ 22,449
U.S.
Disaggregation of Revenue [Line Items]
Total revenues	19,267	18,217	16,645
Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,874	4,135	3,811
Other International
Disaggregation of Revenue [Line Items]
Total revenues	3,164	2,337	1,993
Product sales
Disaggregation of Revenue [Line Items]
Total revenues	27,008	24,355	22,119
Product sales \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	19,176	18,141	16,565
Product sales \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,678	3,894	3,567
Product sales \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	3,154	2,320	1,987
Total HIV
Disaggregation of Revenue [Line Items]
Total revenues	16,315	16,938	16,438
Total HIV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	12,828	13,651	13,315
Total HIV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	2,366	2,287	2,312
Total HIV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	1,121	1,000	811
Atripla
Disaggregation of Revenue [Line Items]
Total revenues	145	349	600
Atripla \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	121	307	501
Atripla \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	12	21	60
Atripla \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	12	21	39
Biktarvy
Disaggregation of Revenue [Line Items]
Total revenues	8,624	7,259	4,738
Biktarvy \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	7,049	6,095	4,225
Biktarvy \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	969	735	370
Biktarvy \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	606	429	143
Complera/Eviplera
Disaggregation of Revenue [Line Items]
Total revenues	258	269	406
Complera/Eviplera \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	102	89	160
Complera/Eviplera \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	142	159	214
Complera/Eviplera \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	14	21	32
Descovy
Disaggregation of Revenue [Line Items]
Total revenues	1,700	1,861	1,500
Descovy \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	1,397	1,526	1,078
Descovy \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	164	197	255
Descovy \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	139	138	167
Genvoya
Disaggregation of Revenue [Line Items]
Total revenues	2,879	3,338	3,931
Genvoya \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	2,267	2,605	2,984
Genvoya \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	391	490	664
Genvoya \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	221	243	283
Odefsey
Disaggregation of Revenue [Line Items]
Total revenues	1,568	1,672	1,655
Odefsey \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	1,076	1,172	1,180
Odefsey \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	440	450	438
Odefsey \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	52	50	37
Stribild
Disaggregation of Revenue [Line Items]
Total revenues	189	196	369
Stribild \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	132	125	268
Stribild \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	43	54	75
Stribild \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	14	17	26
Truvada
Disaggregation of Revenue [Line Items]
Total revenues	371	1,448	2,813
Truvada \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	314	1,376	2,640
Truvada \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	22	27	101
Truvada \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	35	45	72
Revenue share - Symtuza
Disaggregation of Revenue [Line Items]
Total revenues	531	488	379
Revenue share - Symtuza \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	355	331	249
Revenue share - Symtuza \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	165	149	130
Revenue share - Symtuza \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	11	8	0
Other HIV
Disaggregation of Revenue [Line Items]
Total revenues	50	58	47
Other HIV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	15	25	30
Other HIV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	18	5	5
Other HIV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	17	28	12
Veklury
Disaggregation of Revenue [Line Items]
Total revenues	5,565	2,811	0
Veklury \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	3,640	2,026	0
Veklury \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	1,095	607	0
Veklury \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	830	178	0
Total HCV
Disaggregation of Revenue [Line Items]
Total revenues	1,881	2,064	2,936
Total HCV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	1,018	1,088	1,465
Total HCV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	421	414	742
Total HCV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	442	562	729
Ledipasvir/Sofosbuvir
Disaggregation of Revenue [Line Items]
Total revenues	212	272	643
Ledipasvir/Sofosbuvir \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	84	92	312
Ledipasvir/Sofosbuvir \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	31	29	71
Ledipasvir/Sofosbuvir \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	97	151	260
Sofosbuvir/Velpatasvir
Disaggregation of Revenue [Line Items]
Total revenues	1,462	1,599	1,965
Sofosbuvir/Velpatasvir \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	815	864	971
Sofosbuvir/Velpatasvir \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	316	337	553
Sofosbuvir/Velpatasvir \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	331	398	441
Other HCV
Disaggregation of Revenue [Line Items]
Total revenues	207	193	328
Other HCV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	119	132	182
Other HCV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	74	48	118
Other HCV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	14	13	28
Total HBV/HDV
Disaggregation of Revenue [Line Items]
Total revenues	969	860	742
Total HBV/HDV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	397	380	343
Total HBV/HDV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	104	71	99
Total HBV/HDV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	468	409	300
Vemlidy
Disaggregation of Revenue [Line Items]
Total revenues	814	657	488
Vemlidy \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	384	356	309
Vemlidy \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	34	29	21
Vemlidy \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	396	272	158
Viread
Disaggregation of Revenue [Line Items]
Total revenues	111	185	243
Viread \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	11	14	32
Viread \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	28	34	69
Viread \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	72	137	142
Other HB/HDV
Disaggregation of Revenue [Line Items]
Total revenues	44	18	11
Other HB/HDV \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	2	10	2
Other HB/HDV \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	42	8	9
Other HB/HDV \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Total Cell Therapy
Disaggregation of Revenue [Line Items]
Total revenues	871	607	456
Total Cell Therapy \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	542	396	373
Total Cell Therapy \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	293	201	83
Total Cell Therapy \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	36	10	0
Tecartus
Disaggregation of Revenue [Line Items]
Total revenues	176	44	0
Tecartus \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	136	34	0
Tecartus \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	40	10	0
Tecartus \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Yescarta
Disaggregation of Revenue [Line Items]
Total revenues	695	563	456
Yescarta \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	406	362	373
Yescarta \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	253	191	83
Yescarta \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	36	10	0
Trodelvy
Disaggregation of Revenue [Line Items]
Total revenues	380	49	0
Trodelvy \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	370	49	0
Trodelvy \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	10	0	0
Trodelvy \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Total Other
Disaggregation of Revenue [Line Items]
Total revenues	1,027	1,026	1,547
Total Other \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	381	551	1,069
Total Other \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	389	314	331
Total Other \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	257	161	147
AmBisome
Disaggregation of Revenue [Line Items]
Total revenues	540	436	407
AmBisome \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	39	61	37
AmBisome \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	274	230	234
AmBisome \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	227	145	136
Letairis
Disaggregation of Revenue [Line Items]
Total revenues	206	314	618
Letairis \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	206	314	618
Letairis \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Letairis \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Ranexa
Disaggregation of Revenue [Line Items]
Total revenues	10	9	216
Ranexa \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	10	9	216
Ranexa \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Ranexa \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Zydelig
Disaggregation of Revenue [Line Items]
Total revenues	62	72	103
Zydelig \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	26	31	47
Zydelig \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	35	39	54
Zydelig \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	1	2	2
Other
Disaggregation of Revenue [Line Items]
Total revenues	209	195	203
Other \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	100	136	151
Other \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	80	45	43
Other \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	29	14	9
Royalty, contract and other revenues
Disaggregation of Revenue [Line Items]
Total revenues	297	334	330
Royalty, contract and other revenues \| U.S.
Disaggregation of Revenue [Line Items]
Total revenues	91	76	80
Royalty, contract and other revenues \| Europe
Disaggregation of Revenue [Line Items]
Total revenues	196	241	244
Royalty, contract and other revenues \| Other International
Disaggregation of Revenue [Line Items]
Total revenues	$ 10	$ 17	$ 6

Revenues - Summarized Revenues from Major Customers (Details) - Revenue benchmark - Customer concentration risk	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AmerisourceBergen Corporation
Revenue, Major Customer [Line Items]
Percentage of revenues	23.00%	27.00%	21.00%
Cardinal Health, Inc.
Revenue, Major Customer [Line Items]
Percentage of revenues	22.00%	21.00%	21.00%
McKesson Corporation
Revenue, Major Customer [Line Items]
Percentage of revenues	20.00%	20.00%	22.00%

Revenues - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Revenues - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenues recognized from performance obligations satisfied in prior years	$ 851	$ 841	$ 741
Revenues recognized	856	101	$ 257
Contract assets	$ 174	$ 198

Fair Value Measurements - Summary of Assets and Liabilities Recorded at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2021	Mar. 04, 2021	Dec. 31, 2020
Assets
Available-for-sale debt securities	$ 2,497		$ 2,026
Other publicly traded equity securities
Assets
Total	5,743		6,970
Fair value, recurring \| Fair value
Assets
Total	8,320		9,008
Liabilities:
Total	583		339
Fair value, recurring \| Fair value \| MYR
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	317		0
Fair value, recurring \| Fair value \| U.S. treasury securities
Assets
Available-for-sale debt securities	407		309
Fair value, recurring \| Fair value \| U.S. government agencies securities
Assets
Available-for-sale debt securities	4		0
Fair value, recurring \| Fair value \| Non-U.S. government securities
Assets
Available-for-sale debt securities	50		43
Fair value, recurring \| Fair value \| Certificates of deposit
Assets
Available-for-sale debt securities	249		216
Fair value, recurring \| Fair value \| Corporate debt securities
Assets
Available-for-sale debt securities	1,363		1,142
Fair value, recurring \| Fair value \| Residential mortgage and asset-backed securities
Assets
Available-for-sale debt securities	424		316
Fair value, recurring \| Fair value \| Money market funds
Assets
Marketable equity securities	3,661		4,361
Fair value, recurring \| Fair value \| Other publicly traded equity securities
Assets
Marketable equity securities	331		531
Fair value, recurring \| Fair value \| Other publicly traded equity securities \| Galapagos
Assets
Marketable equity securities	931		1,648
Fair value, recurring \| Fair value \| Other publicly traded equity securities \| Arcus
Assets
Marketable equity securities	559		212
Fair value, recurring \| Fair value \| Deferred compensation plan
Assets
Marketable equity securities	261		218
Liabilities:
Deferred compensation plan	261		218
Fair value, recurring \| Fair value \| Foreign currency derivative contracts
Assets
Foreign currency derivative contracts	80		12
Liabilities:
Foreign currency derivative contracts	5		121
Fair value, recurring \| Level 1
Assets
Total	6,150		7,279
Liabilities:
Total	261		218
Fair value, recurring \| Level 1 \| MYR
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	0		0
Fair value, recurring \| Level 1 \| U.S. treasury securities
Assets
Available-for-sale debt securities	407		309
Fair value, recurring \| Level 1 \| U.S. government agencies securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 1 \| Non-U.S. government securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 1 \| Certificates of deposit
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 1 \| Corporate debt securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 1 \| Residential mortgage and asset-backed securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 1 \| Money market funds
Assets
Marketable equity securities	3,661		4,361
Fair value, recurring \| Level 1 \| Other publicly traded equity securities
Assets
Marketable equity securities	331		531
Fair value, recurring \| Level 1 \| Other publicly traded equity securities \| Galapagos
Assets
Marketable equity securities	931		1,648
Fair value, recurring \| Level 1 \| Other publicly traded equity securities \| Arcus
Assets
Marketable equity securities	559		212
Fair value, recurring \| Level 1 \| Deferred compensation plan
Assets
Marketable equity securities	261		218
Liabilities:
Deferred compensation plan	261		218
Fair value, recurring \| Level 1 \| Foreign currency derivative contracts
Assets
Foreign currency derivative contracts	0		0
Liabilities:
Foreign currency derivative contracts	0		0
Fair value, recurring \| Level 2
Assets
Total	2,170		1,729
Liabilities:
Total	5		121
Fair value, recurring \| Level 2 \| MYR
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	0		0
Fair value, recurring \| Level 2 \| U.S. treasury securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 2 \| U.S. government agencies securities
Assets
Available-for-sale debt securities	4		0
Fair value, recurring \| Level 2 \| Non-U.S. government securities
Assets
Available-for-sale debt securities	50		43
Fair value, recurring \| Level 2 \| Certificates of deposit
Assets
Available-for-sale debt securities	249		216
Fair value, recurring \| Level 2 \| Corporate debt securities
Assets
Available-for-sale debt securities	1,363		1,142
Fair value, recurring \| Level 2 \| Residential mortgage and asset-backed securities
Assets
Available-for-sale debt securities	424		316
Fair value, recurring \| Level 2 \| Money market funds
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 2 \| Other publicly traded equity securities
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 2 \| Other publicly traded equity securities \| Galapagos
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 2 \| Other publicly traded equity securities \| Arcus
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 2 \| Deferred compensation plan
Assets
Marketable equity securities	0		0
Liabilities:
Deferred compensation plan	0		0
Fair value, recurring \| Level 2 \| Foreign currency derivative contracts
Assets
Foreign currency derivative contracts	80		12
Liabilities:
Foreign currency derivative contracts	5		121
Fair value, recurring \| Level 3
Assets
Total	0		0
Liabilities:
Total	317		0
Fair value, recurring \| Level 3 \| MYR
Liabilities:
Liability for MYR GmbH (“MYR”) contingent consideration	317	$ 341	0
Fair value, recurring \| Level 3 \| U.S. treasury securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| U.S. government agencies securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| Non-U.S. government securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| Certificates of deposit
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| Corporate debt securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| Residential mortgage and asset-backed securities
Assets
Available-for-sale debt securities	0		0
Fair value, recurring \| Level 3 \| Money market funds
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 3 \| Other publicly traded equity securities
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 3 \| Other publicly traded equity securities \| Galapagos
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 3 \| Other publicly traded equity securities \| Arcus
Assets
Marketable equity securities	0		0
Fair value, recurring \| Level 3 \| Deferred compensation plan
Assets
Marketable equity securities	0		0
Liabilities:
Deferred compensation plan	0		0
Fair value, recurring \| Level 3 \| Foreign currency derivative contracts
Assets
Foreign currency derivative contracts	0		0
Liabilities:
Foreign currency derivative contracts	$ 0		$ 0

Fair Value Measurements - Summary of Classification on Balance Sheet (Details) - Equity Securities - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities
Total	$ 5,743	$ 6,970
Cash and cash equivalents
Fair Value, Assets and Liabilities
Marketable equity securities	3,661	4,361
Prepaid and other current assets
Fair Value, Assets and Liabilities
Marketable equity securities	885	853
Other long-term assets
Fair Value, Assets and Liabilities
Marketable equity securities	$ 1,197	$ 1,756

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 04, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized loss on investment of equity securities	$ 610,000,000	$ 1,700,000,000
Unrealized gain on investment of equity securities			$ 1,200,000,000
Other equity investments without readily determinable fair values	338,000,000	262,000,000
In-process research and development impairment	0	0	800,000,000
Kite Pharma, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
In-process research and development impairment			$ 800,000,000
Equity Securities Donation \| Gilead Foundation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Donation expense	212,000,000
Level 2 \| MYR \| Fair value, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration	0	0
Level 3 \| MYR \| Fair value, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration	317,000,000	0		$ 341,000,000
Fair value \| MYR \| Fair value, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration	317,000,000	0
Fair value \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term and long-term debt	28,600,000,000	34,600,000,000
Fair value \| Level 3 \| Immunomedics, Inc. \| Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Future royalties	1,300,000,000	1,100,000,000
Carrying value \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term and long-term debt	25,600,000,000	30,300,000,000
Carrying value \| Level 3 \| Immunomedics, Inc. \| Fair Value, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Future royalties	$ 1,100,000,000	$ 1,100,000,000

Available-for-Sale Debt Securities - Summary of Available-for-Sale Debt Securities at Estimated Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Available-for-Sale Securities
Amortized Cost	$ 2,501	$ 2,023
Gross Unrealized Gains	0	3
Gross Unrealized Losses	(4)	0
Estimated Fair Value	2,497	2,026
U.S. treasury securities
Available-for-Sale Securities
Amortized Cost	408	308
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(1)	0
Estimated Fair Value	407	309
U.S. government agencies securities
Available-for-Sale Securities
Amortized Cost	4	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	4	0
Non-U.S. government securities
Available-for-Sale Securities
Amortized Cost	50	43
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	50	43
Certificates of deposit
Available-for-Sale Securities
Amortized Cost	249	216
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	249	216
Corporate debt securities
Available-for-Sale Securities
Amortized Cost	1,365	1,140
Gross Unrealized Gains	0	2
Gross Unrealized Losses	(2)	0
Estimated Fair Value	1,363	1,142
Residential mortgage and asset-backed securities
Available-for-Sale Securities
Amortized Cost	425	316
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	0
Estimated Fair Value	$ 424	$ 316

Available-for-Sale Debt Securities - Summary of the Balance Sheet Classification of Available-for-Sale Debt Securities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Total	$ 2,497	$ 2,026
Cash and cash equivalents
Debt Securities, Available-for-sale [Line Items]
Total	6	113
Short-term marketable debt securities
Debt Securities, Available-for-sale [Line Items]
Total	1,182	1,411
Long-term marketable debt securities
Debt Securities, Available-for-sale [Line Items]
Total	$ 1,309	$ 502

Available-for-Sale Debt Securities - Summary of Available-for-Sale Debt Securities by Contractual Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Amortized Cost
Within one year	$ 1,189
After one year through five years	1,288
After five years	24
Amortized Cost	2,501	$ 2,023
Fair Value
Within one year	1,188
After one year through five years	1,286
After five years	23
Total	$ 2,497	$ 2,026

Available-for-Sale Debt Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2021 USD ($) position	Dec. 31, 2020 USD ($) position	Dec. 31, 2019 USD ($)
Debt Securities, Available-for-sale [Abstract]
Securities in unrealized loss positions, number of positions (securities) \| position	534	75
Impairment loss recognized \| $	$ 0	$ 0	$ 0

Derivative Financial Instruments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Outstanding notional amounts on foreign currency exchange contracts	$ 2,900,000,000	$ 2,400,000,000
Gain (loss) on discontinuance of cash flow hedges	$ 0	$ 0
Maximum
Derivative [Line Items]
Maturity on derivative instruments	18 months
Time estimate for gains (losses) to be reclassified from AOCI to product sales	12 months

Derivative Financial Instruments - Summary of Classification and Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 80	$ 12
Derivative Liabilities	5	121
Designated as hedging instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	80	0
Derivative Liabilities	5	120
Designated as hedging instrument \| Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	75	0
Designated as hedging instrument \| Accrued and other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	4	113
Designated as hedging instrument \| Other long-term assets
Derivatives, Fair Value [Line Items]
Derivative Assets	5	0
Designated as hedging instrument \| Other long-term obligations
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1	7
Not designated as hedging instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	0	12
Derivative Liabilities	0	1
Not designated as hedging instrument \| Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	12
Not designated as hedging instrument \| Accrued and other current liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 0	$ 1

Derivative Financial Instruments - Summary of Effect of Foreign Currency Exchange Contracts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gain (loss) recognized in AOCI	$ 147	$ (118)	$ 76
Gain (loss) reclassified from AOCI into Product sales	(67)	47	127
Gain (loss) recognized in Other income (expense), net	$ 21	$ (51)	$ 22

Derivative Financial Instruments - Summary of Potential Effect of Offsetting Derivatives (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivative assets
Gross Amounts of Recognized Assets/Liabilities	$ 80	$ 12
Gross Amounts Offset on the Consolidated Balance Sheets	0	0
Amounts of Assets/Liabilities Presented on the Consolidated Balance Sheets	80	12
Derivative Financial Instruments	(4)	(12)
Cash Collateral Received/Pledged	0	0
Net Amount (Legal Offset)	76	0
Derivative liabilities
Gross Amounts of Recognized Assets/Liabilities	5	121
Gross Amounts Offset on the Consolidated Balance Sheets	0	0
Amounts of Assets/Liabilities Presented on the Consolidated Balance Sheets	5	121
Derivative Financial Instruments	(4)	(12)
Cash Collateral Received/Pledged	0	0
Net Amount (Legal Offset)	$ 1	$ 109

Acquisitions - Narrative (Details) € in Millions					1 Months Ended	12 Months Ended
Acquisitions - Narrative (Details) € in Millions	Mar. 04, 2021 USD ($)	Mar. 04, 2021 EUR (€)	Oct. 23, 2020 USD ($)	Apr. 07, 2020 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Apr. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Mar. 04, 2021 EUR (€)
Business Acquisition [Line Items]
Discount rate of acquired IPR&D						6.50%	8.00%	9.50%
Acquired in-process research and development expenses						$ 177,000,000	$ 5,856,000,000	$ 4,251,000,000
Acquired IPR&D
Business Acquisition [Line Items]
Reclassified intangible assets									$ (1,000,000,000)	$ (910,000,000)
Trodelvy
Business Acquisition [Line Items]
Reclassified intangible assets									$ 1,000,000,000
Forty Seven, Inc.
Business Acquisition [Line Items]
Accelerated stock-based expense							144,000,000
Total consideration, net of acquired cash				$ 4,700,000,000
Forty Seven, Inc. \| Acquired IPR&D
Business Acquisition [Line Items]
Acquired in-process research and development expenses							4,500,000,000
MYR
Business Acquisition [Line Items]
Consideration	$ 1,600,000,000	€ 1,300
Cash payments made for acquisition	1,200,000,000	€ 1,000
Goodwill	226,000,000
Goodwill expected to be deductible for tax purposes						0
MYR \| Level 3 \| Fair value, recurring
Business Acquisition [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration	341,000,000					317,000,000	0
MYR \| Maximum
Business Acquisition [Line Items]
Liability for MYR GmbH (“MYR”) contingent consideration \| €											€ 300
MYR \| Acquired IPR&D
Business Acquisition [Line Items]
Aggregate fair value of acquired IPR&D	1,190,000,000
MYR \| Hepcludex
Business Acquisition [Line Items]
Aggregate fair value of acquired IPR&D	$ 1,190,000,000
MYR \| Hepcludex \| Measurement Input, Discount Rate
Business Acquisition [Line Items]
Discount rate of acquired IPR&D	12.00%										12.00%
MYR \| Hepcludex
Business Acquisition [Line Items]
Finite-lived intangible asset	$ 845,000,000
Estimated useful life of finite-lived intangible asset acquired	10 years	10 years
MYR \| Hepcludex \| Measurement Input, Discount Rate
Business Acquisition [Line Items]
Discount rate of finite-lived intangible asset acquired	12.00%										12.00%
Immunomedics, Inc.
Business Acquisition [Line Items]
Consideration			$ 20,600,000,000
Goodwill			3,991,000,000
Goodwill expected to be deductible for tax purposes			0
Accelerated stock-based expense							289,000,000
Acquisition-related expenses							39,000,000
Fair value step-up adjustment of inventories acquired			881,000,000
Inventories			946,000,000			$ 294,000,000	$ 797,000,000
Liability related to future royalties			$ 1,100,000,000
Immunomedics, Inc. \| Measurement Input, Risk Free Interest Rate
Business Acquisition [Line Items]
Liability related to future royalties, measurement Input			0.025
Immunomedics, Inc. \| Measurement Input, Expected Term
Business Acquisition [Line Items]
Liability related to future royalties, measurement Input			16
Immunomedics, Inc. \| Three year senior unsecured term loan facility \| Medium-term notes
Business Acquisition [Line Items]
Borrowing under the senior unsecured term loan facility					$ 1,000,000,000
Immunomedics, Inc. \| Acquired IPR&D
Business Acquisition [Line Items]
Aggregate fair value of acquired IPR&D			$ 15,760,000,000
Discount rate of acquired IPR&D			7.00%
Immunomedics, Inc. \| Trodelvy
Business Acquisition [Line Items]
Finite-lived intangible asset			$ 4,600,000,000
Discount rate of finite-lived intangible asset acquired			7.00%
Estimated useful life of finite-lived intangible asset acquired			12 years
Immunomedics, Inc. \| Outlicense contract
Business Acquisition [Line Items]
Finite-lived intangible asset			$ 175,000,000
Discount rate of finite-lived intangible asset acquired			7.00%
Estimated useful life of finite-lived intangible asset acquired			15 years

Acquisitions - Summarized Fair Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Dec. 31, 2021	Mar. 04, 2021	Dec. 31, 2020	Oct. 23, 2020
MYR
Intangible assets:
Deferred income taxes, net		$ (513)
Other assets (and liabilities), net		(187)
Total identifiable net assets		1,335
Goodwill		226
Total consideration		1,561
MYR \| Acquired IPR&D
Intangible assets:
Acquired IPR&D		1,190
MYR \| Hepcludex
Intangible assets:
Finite-lived intangible asset		$ 845
Immunomedics, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents				$ 726
Inventories	$ 294		$ 797	946
Intangible assets:
Deferred income taxes, net				(4,565)
Liability related to future royalties				(1,100)
Other assets (and liabilities), net				64
Total identifiable net assets				16,606
Goodwill				3,991
Total consideration				20,597
Immunomedics, Inc. \| Acquired IPR&D
Intangible assets:
Acquired IPR&D				15,760
Immunomedics, Inc. \| Trodelvy
Intangible assets:
Finite-lived intangible asset				4,600
Immunomedics, Inc. \| Outlicense contract
Intangible assets:
Finite-lived intangible asset				$ 175

Inventories - Schedule of inventories (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Schedule of Inventory [Line Items]
Raw materials	$ 1,112	$ 1,080
Work in process	590	976
Finished goods	1,032	958
Inventories	1,618	1,683
Other long-term assets	1,116	1,331
Total assets
Schedule of Inventory [Line Items]
Inventories	$ 2,734	$ 3,014

Inventories - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Inventories - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Oct. 23, 2020
Schedule of Inventory [Line Items]
Inventory write-downs	$ 228	$ 86	$ 649
Immunomedics, Inc.
Schedule of Inventory [Line Items]
Inventories	$ 294	$ 797		$ 946
Inventory Write-downs for Excess Raw Materials
Schedule of Inventory [Line Items]
Inventory write-downs			$ 547

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Land and land improvements	$ 404	$ 404
Buildings and improvements (including leasehold improvements)	3,794	3,678
Laboratory and manufacturing equipment	952	904
Office, computer equipment and other	807	793
Construction in progress	1,057	856
Subtotal	7,014	6,635
Less: accumulated depreciation and amortization	1,893	1,668
Total	$ 5,121	$ 4,967

Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Unamortized capitalized software costs	$ 131	$ 124
Property, plant and equipment, net	5,121	4,967
United States
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	4,100	4,000
Non-US
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 963	$ 940

Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Beginning balance	$ 8,108	$ 4,117
Goodwill resulting from acquisitions	226	3,991
Measurement period adjustments	(2)	0
Ending balance	$ 8,332	$ 8,108

Goodwill and Intangible Assets - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Accumulated goodwill impairment losses	$ 0
Discount rate of acquired IPR&D	6.50%	8.00%	9.50%
In-process research and development impairment	$ 0	$ 0	$ 800,000,000
Kite Pharma, Inc.
Intangible Assets [Line Items]
In-process research and development impairment			800,000,000
Cost of goods sold
Intangible Assets [Line Items]
Aggregate amortization expense related to finite-lived intangible assets	$ 1,700,000,000	$ 1,200,000,000	$ 1,100,000,000

Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Apr. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Finite-lived assets
Gross Carrying Amount	$ 25,915			$ 22,897
Accumulated Amortization	(8,381)			(6,660)
Foreign Currency Translation Adjustment	1			(1)
Total	17,535			16,236
Total intangible assets
Gross Carrying Amount	41,835			39,787
Accumulated Amortization	(8,381)			(6,660)
Foreign Currency Translation Adjustment	1			(1)
Net Carrying Amount	33,455			33,126
Acquired IPR&D
Indefinite-lived assets - IPR&D
Gross Carrying Amount	15,920			16,890
Foreign Currency Translation Adjustment	0			0
Net Carrying Amount	15,920			16,890
Total intangible assets
Reclassified intangible assets		$ (1,000)	$ (910)
Intangible asset - sofosbuvir
Finite-lived assets
Gross Carrying Amount	10,720			10,720
Accumulated Amortization	(5,651)			(4,952)
Foreign Currency Translation Adjustment	0			0
Total	5,069			5,768
Total intangible assets
Accumulated Amortization	(5,651)			(4,952)
Intangible asset - axicabtagene ciloleucel
Finite-lived assets
Gross Carrying Amount	7,110			6,200
Accumulated Amortization	(1,501)			(1,105)
Foreign Currency Translation Adjustment	0			0
Total	5,609			5,095
Total intangible assets
Accumulated Amortization	(1,501)			(1,105)
Reclassified intangible assets			$ 910
Intangible asset - Trodelvy
Finite-lived assets
Gross Carrying Amount	5,630			4,600
Accumulated Amortization	(507)			(63)
Foreign Currency Translation Adjustment	0			0
Total	5,123			4,537
Total intangible assets
Accumulated Amortization	(507)			(63)
Reclassified intangible assets		$ 1,000
Intangible asset - Hepcludex
Finite-lived assets
Gross Carrying Amount	845			0
Accumulated Amortization	(72)			0
Foreign Currency Translation Adjustment	0			0
Total	773			0
Total intangible assets
Accumulated Amortization	(72)			0
Other
Finite-lived assets
Gross Carrying Amount	1,610			1,377
Accumulated Amortization	(650)			(540)
Foreign Currency Translation Adjustment	1			(1)
Total	961			836
Total intangible assets
Accumulated Amortization	(650)			$ (540)
Reclassified intangible assets	(200)
Tecartus
Total intangible assets
Reclassified intangible assets	$ 200

Goodwill and Intangible Assets - Estimated Future Amortization Expense of Finite-Lived Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
2022	$ 1,778
2023	1,778
2024	1,778
2025	1,773
2026	1,765
Thereafter	8,663
Total	$ 17,535	$ 16,236

Other Financial Information - Accounts Receivable, Net (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Other Financial Information [Abstract]
Accounts receivable	$ 5,278	$ 5,560
Less: chargebacks	671	552
Less: cash discounts and other	67	72
Less: allowances for credit losses	47	44
Accounts receivable, net	$ 4,493	$ 4,892

Other Financial Information - Other Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Other Financial Information [Abstract]
Compensation and employee benefits	$ 927	$ 864
Income taxes payable	539	598
Allowance for sales returns	499	587
Accrual for settlement related to bictegravir litigation	1,250	0
Other accrued liabilities	2,930	2,287
Accrued and other current liabilities	$ 6,145	$ 4,336

Collaborations and Other Arrangements (Details) € / shares in Units, € in Millions, shares in Millions								1 Months Ended					3 Months Ended	12 Months Ended
	Dec. 21, 2021 USD ($)	Mar. 13, 2021 USD ($)	Aug. 25, 2020 USD ($)	Aug. 17, 2020 USD ($) program	Jul. 13, 2020 USD ($) shares	May 29, 2020 USD ($) shares	May 27, 2020	Jan. 31, 2021 USD ($)	Jan. 31, 2021 EUR (€)	Oct. 31, 2020 USD ($)	Aug. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Mar. 31, 2021 USD ($) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) shares	Dec. 31, 2014	Dec. 31, 2021 EUR (€) shares	Nov. 18, 2021 program	Apr. 30, 2021 USD ($)	Apr. 30, 2021 EUR (€)	Feb. 08, 2021	Dec. 15, 2020 EUR (€)	Jul. 17, 2020	Jun. 19, 2020	Aug. 31, 2019 € / shares	Jul. 31, 2018 USD ($)	Jan. 19, 2016 € / shares shares
Collaborative Arrangements
Acquired in-process research and development expenses														$ 177,000,000	$ 5,856,000,000	$ 4,251,000,000
Unrealized loss on investment of equity securities														610,000,000	1,700,000,000
Unrealized gain on investment of equity securities																1,200,000,000
Prepaid and other current assets														2,141,000,000	2,013,000,000
Other long-term assets														4,963,000,000	5,708,000,000
Cost of goods sold														6,601,000,000	4,572,000,000	4,675,000,000
Merck Sharp & Dohme Corp
Collaborative Arrangements
Percent of global and development and commercialization costs		60.00%
Revenues recognized														0
Option period to license certain inhibitors		5 years
Merck Sharp & Dohme Corp \| Oral Formulation Product
Collaborative Arrangements
Net product sales threshold		$ 2,000,000,000
Percent of global product revenues		65.00%
Merck Sharp & Dohme Corp \| Injectable Formulation Product
Collaborative Arrangements
Net product sales threshold		$ 3,500,000,000
Merck Sharp & Dohme Corp \| Merck
Collaborative Arrangements
Percent of global and development and commercialization costs		40.00%
Arcus stock purchase agreement \| Arcus
Collaborative Arrangements
Ownership percentage by noncontrolling owners																						19.50%
Janssen pharmaceuticals
Collaborative Arrangements
Purchase price of goods less specified amount, maximum percentage																	30.00%
Cost of goods sold														530,000,000	570,000,000	574,000,000
Period subject to termination																	10 years
Jounce license and stock purchase agreement \| Jounce
Collaborative Arrangements
Ownership percentage by noncontrolling owners										14.00%
Japan tobacco
Collaborative Arrangements
Royalty expense														250,000,000	291,000,000	358,000,000
Cash paid												$ 559,000,000
Finite-lived intangible assets acquired												$ 550,000,000
Amortization useful life												9 years
Gadeta collaboration arrangement
Collaborative Arrangements
Noncontrolling interest in variable interest entity																82,000,000											$ 82,000,000
Other collaboration arrangements
Collaborative Arrangements
Cash payments made related to equity investments														147,000,000	72,000,000	118,000,000
Upfront collaboration expenses														177,000,000	129,000,000	331,000,000
Arcus
Collaborative Arrangements
Payments to acquire shares						$ 61,000,000
Shares of common stock acquired (in shares) \| shares						2.2
Arcus \| Arcus collaboration agreement and stock purchase agreements
Collaborative Arrangements
Payments to acquire in process research and development					$ 175,000,000
Additional shares acquired (in shares) \| shares					6.0
Payments to acquire shares					$ 200,000,000
Total upfront payments made					391,000,000
Equity investment					135,000,000									559,000,000	212,000,000
Acquired in-process research and development expenses					256,000,000
Issuance discount (premium)					(65,000,000)
Direct transactional costs					16,000,000
Opt-in term							10 years
Number of clinical stage programs with exercise options \| program																			3
Collaboration opt-in payments	$ 725,000,000
Research and development expenses														625,000,000
Unrealized gain on investment of equity securities														$ 127,000,000	80,000,000
Arcus \| Arcus collaboration agreement
Collaborative Arrangements
Additional option fee on fourth, sixth, and eighth anniversaries					$ 100,000,000
Arcus \| Arcus stock purchase agreement
Collaborative Arrangements
Payments to acquire shares													$ 220,000,000
Purchase period					5 years
Maximum percentage of outstanding stock allowed to be purchased					35.00%
Restriction period					3 years
Additional shares acquired (in shares) \| shares													5.7
Number of shares (in shares) \| shares														13.8				13.8
Pionyr
Collaborative Arrangements
Ownership percentage																									49.90%
Pionyr \| Pionyr merger and option agreements
Collaborative Arrangements
Acquired in-process research and development expenses															215,000,000
Equity investments balance														$ 0	0
Payments to acquire equity method investments					$ 269,000,000
Estimated fair value					70,000,000
Option exercise fee					315,000,000
Maximum potential future milestone payments					1,200,000,000
Pionyr \| Research and development service agreement
Collaborative Arrangements
Acquired in-process research and development expenses															80,000,000
Research and development future maximum payments					$ 115,000,000
Cash payments made for research and development milestones													$ 70,000,000
Tizona
Collaborative Arrangements
Ownership percentage																								49.90%
Tizona \| Tizona merger and option agreements
Collaborative Arrangements
Acquired in-process research and development expenses															272,000,000
Equity investments balance														0	0
Payments to acquire equity method investments			$ 302,000,000
Estimated fair value			41,000,000
Option exercise fee			100,000,000
Tizona \| Tizona merger and option agreements \| Maximum
Collaborative Arrangements
Option fee and potential future milestone payments			$ 1,200,000,000
Tizona \| Development agreement
Collaborative Arrangements
Acquired in-process research and development expenses															115,000,000
Tango \| Tango collaboration and stock purchase agreement
Collaborative Arrangements
Payments to acquire in process research and development				$ 125,000,000
Payments to acquire shares				13,000,000
Acquired in-process research and development expenses				$ 125,000,000
Collaboration term				7 years
Cash payments made related to equity investments				$ 20,000,000
Number of programs \| program				15
Tango \| Tango collaboration and stock purchase agreement \| Maximum
Collaborative Arrangements
Opt-in, extension and milestone payments				$ 410,000,000
Jounce \| Jounce license and stock purchase agreement
Collaborative Arrangements
Total upfront payments made										$ 120,000,000
Acquired in-process research and development expenses														64,000,000
Cash payments made related to equity investments										$ 56,000,000
Future potential clinical, regulatory and commercial milestone payments														660,000,000
Galapagos \| Filgotinib agreement
Collaborative Arrangements
Shares of common stock acquired (in shares) \| shares																												6.8
Share price (in dollars per share) \| € / shares																												€ 58
Galapagos \| Amended 2019 agreement
Collaborative Arrangements
Payment of tiered royalties, low-end percentage																							8.00%
Payment of tiered royalties, high-end percentage																							15.00%
Potential payment for adjustments of budgeted development costs																190,000,000							€ 160
Payment for adjustments of budgeted development costs								$ 43,000,000	€ 35
Additional payment for adjustments of budgeted development costs in 2021																				$ 88,000,000	€ 75
Payment for adjustments of budgeted development costs in 2022														60,000,000				€ 50
Galapagos \| Galapagos subscription agreement
Collaborative Arrangements
Additional shares acquired (in shares) \| shares											2.6
Acquired in-process research and development expenses																$ 3,920,000,000
Shares of common stock acquired (in shares) \| shares											6.8					16.7
Equity investments balance											$ 1,130,000,000			931,000,000
Unrealized loss on investment of equity securities														$ 717,000,000	1,800,000,000
Unrealized gain on investment of equity securities															1,200,000,000
Ownership percentage											25.80%
Share price (in dollars per share) \| € / shares																										€ 140.59
Estimated fair value											$ 586,000,000
Payment for license and option rights											5,050,000,000.00
Issuance discount											$ 63,000,000
Maximum ownership percentage											29.90%
Standstill restricting term											10 years
Minimum ownership percentage											20.10%
Prepaid and other current assets															351,000,000
Other long-term assets															$ 1,300,000,000
Galapagos \| Galapagos collaboration agreement
Collaborative Arrangements
Payment of tiered royalties, low-end percentage											20.00%
Payment of tiered royalties, high-end percentage											24.00%
Potential option exercise fee											$ 150,000,000

Debt and Credit Facilities - Summary of Debt Carrying Amount (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total	$ 26,695	$ 31,402
Less: current portion of long-term debt and other obligations, net	1,516	2,757
Total long-term debt, net	25,179	28,645
Senior Notes And Medium-Term Notes
Debt Instrument [Line Items]
Total	25,571	30,295
Senior notes
Debt Instrument [Line Items]
Total	$ 25,750
Senior notes \| 4.50% Senior Unsecured Notes Due in April 2021
Debt Instrument [Line Items]
Interest Rate	4.50%
Total	$ 0	1,000
Senior notes \| 0.15% LIBOR Senior Unsecured Notes Due September 2021
Debt Instrument [Line Items]
Total	$ 0	499
Senior notes \| 4.40% Senior Unsecured Notes Due In December 2021
Debt Instrument [Line Items]
Interest Rate	4.40%
Total	$ 0	1,249
Senior notes \| 1.95% Senior Unsecured Notes Due in March 2022
Debt Instrument [Line Items]
Interest Rate	1.95%
Total	$ 500	499
Senior notes \| 3.25% Senior Unsecured Notes Due in September 2022
Debt Instrument [Line Items]
Interest Rate	3.25%
Total	$ 999	998
Senior notes \| 2.50% Senior Unsecured Notes Due in September 2023
Debt Instrument [Line Items]
Interest Rate	2.50%
Total	$ 748	748
Senior notes \| 0.52% LIBOR Senior Unsecured Notes Due September 2023
Debt Instrument [Line Items]
Total	$ 0	498
Senior notes \| 0.75% Senior Unsecured Notes Due in September 2023
Debt Instrument [Line Items]
Interest Rate	0.75%
Total	$ 1,496	1,992
Senior notes \| 3.70% Senior Unsecured Notes Due in April 2024
Debt Instrument [Line Items]
Interest Rate	3.70%
Total	$ 1,747	1,746
Senior notes \| 3.50% Senior Unsecured Notes Due in February 2025
Debt Instrument [Line Items]
Interest Rate	3.50%
Total	$ 1,747	1,746
Senior notes \| 3.65% Senior Unsecured Notes Due in March 2026
Debt Instrument [Line Items]
Interest Rate	3.65%
Total	$ 2,739	2,737
Senior notes \| 2.95% Senior Unsecured Notes Due in March 2027
Debt Instrument [Line Items]
Interest Rate	2.95%
Total	$ 1,247	1,246
Senior notes \| 1.20% Senior Unsecured Notes Due October 2027
Debt Instrument [Line Items]
Interest Rate	1.20%
Total	$ 746	745
Senior notes \| 1.65% Senior Unsecured Notes Due October 2030
Debt Instrument [Line Items]
Interest Rate	1.65%
Total	$ 993	992
Senior notes \| 4.60% Senior Unsecured Notes Due in September 2035
Debt Instrument [Line Items]
Interest Rate	4.60%
Total	$ 992	991
Senior notes \| 4.00% Senior Unsecured Notes Due in September 2036
Debt Instrument [Line Items]
Interest Rate	4.00%
Total	$ 742	741
Senior notes \| 2.60% Senior Unsecured Notes Due October 2040
Debt Instrument [Line Items]
Interest Rate	2.60%
Total	$ 987	986
Senior notes \| 5.65% Senior Unsecured Notes Due in December 2041
Debt Instrument [Line Items]
Interest Rate	5.65%
Total	$ 996	996
Senior notes \| 4.80% Senior Unsecured Notes Due in April 2044
Debt Instrument [Line Items]
Interest Rate	4.80%
Total	$ 1,736	1,735
Senior notes \| 4.50% Senior Unsecured Notes Due in February 2045
Debt Instrument [Line Items]
Interest Rate	4.50%
Total	$ 1,733	1,732
Senior notes \| 4.75% Senior Unsecured Notes Due in March 2046
Debt Instrument [Line Items]
Interest Rate	4.75%
Total	$ 2,220	2,219
Senior notes \| 4.15% Senior Unsecured Notes Due in March 2047
Debt Instrument [Line Items]
Interest Rate	4.15%
Total	$ 1,727	1,726
Senior notes \| 2.80% Senior Unsecured Notes Due October 2050
Debt Instrument [Line Items]
Interest Rate	2.80%
Total	$ 1,476	1,476
Medium-term notes \| Variable Term Loan Note Due October 2023
Debt Instrument [Line Items]
Total	0	998
Other notes payable
Debt Instrument [Line Items]
Total	$ 1,124	$ 1,107
LIBOR rate \| Senior notes \| 0.15% LIBOR Senior Unsecured Notes Due September 2021
Debt Instrument [Line Items]
Basis spread on variable rate	0.15%
LIBOR rate \| Senior notes \| 0.52% LIBOR Senior Unsecured Notes Due September 2023
Debt Instrument [Line Items]
Basis spread on variable rate	0.52%

Debt and Credit Facilities - Narrative (Details)		1 Months Ended					3 Months Ended			12 Months Ended
Debt and Credit Facilities - Narrative (Details)	May 31, 2016 USD ($)	Dec. 31, 2021 USD ($)	Oct. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2021 USD ($) repayment	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Oct. 31, 2020 USD ($)
Debt Instrument [Line Items]
Repayments of debt										$ 4,750,000,000
Debt issued										0
Long-term debt		$ 26,695,000,000					$ 26,695,000,000			26,695,000,000	$ 31,402,000,000
Interest expense										1,000,000,000	1,000,000,000	$ 1,000,000,000
Senior notes
Debt Instrument [Line Items]
Repayments of unsecured debt										$ 3,750,000,000
Redemption price, percentage of principal amount repurchased										100.00%
Redemption price, percentage										101.00%
Long-term debt		$ 25,750,000,000					25,750,000,000			$ 25,750,000,000
Medium-term notes
Debt Instrument [Line Items]
Repayments of debt							$ 1,000,000,000
Number of early repayments \| repayment							2
4.50% Senior Unsecured Notes Due in April 2021 \| Senior notes
Debt Instrument [Line Items]
Repayments of unsecured debt									$ 1,000,000,000
Interest rate, stated percentage		4.50%					4.50%			4.50%
Long-term debt		$ 0					$ 0			$ 0	1,000,000,000
4.40% Senior Unsecured Notes Due In December 2021 \| Senior notes
Debt Instrument [Line Items]
Repayments of unsecured debt								$ 1,250,000,000
Interest rate, stated percentage		4.40%					4.40%			4.40%
Long-term debt		$ 0					$ 0			$ 0	1,249,000,000
0.15% LIBOR Senior Unsecured Notes Due September 2021 \| Senior notes
Debt Instrument [Line Items]
Repayments of unsecured debt				$ 500,000,000
Long-term debt		$ 0					$ 0			$ 0	499,000,000
0.75% Senior Unsecured Notes Due in September 2023 \| Senior notes
Debt Instrument [Line Items]
Repayments of debt			$ 500,000,000
Interest rate, stated percentage		0.75%					0.75%			0.75%
Long-term debt		$ 1,496,000,000					$ 1,496,000,000			$ 1,496,000,000	1,992,000,000
0.52% LIBOR Senior Unsecured Notes Due September 2023 \| Senior notes
Debt Instrument [Line Items]
Repayments of debt			$ 500,000,000
Long-term debt		0					$ 0			$ 0	498,000,000
1.95% Senior Unsecured Notes Due in March 2022 \| Senior notes
Debt Instrument [Line Items]
Repayments of unsecured debt		$ 500,000,000
Interest rate, stated percentage		1.95%					1.95%			1.95%
Long-term debt		$ 500,000,000					$ 500,000,000			$ 500,000,000	499,000,000
the "2020 Fixed Rate Notes" \| Senior notes \| Minimum
Debt Instrument [Line Items]
Call feature, period prior to maturity										1 month
the "2020 Fixed Rate Notes" \| Senior notes \| Maximum
Debt Instrument [Line Items]
Call feature, period prior to maturity										2 years
Three year senior unsecured term loan facility \| Medium-term notes
Debt Instrument [Line Items]
Repayments of debt										$ 1,000,000,000
Debt instrument, term					3 years
Maximum borrowing capacity					$ 1,000,000,000
Principal amount													$ 1,000,000,000
2016 revolving credit facility \| Line of credit \| Revolving credit facility
Debt Instrument [Line Items]
Debt instrument, term	5 years
Maximum borrowing capacity	$ 2,500,000,000
2020 revolving credit facility \| Line of credit \| Revolving credit facility
Debt Instrument [Line Items]
Debt instrument, term						5 years
Maximum borrowing capacity						$ 2,500,000,000
Amounts outstanding under the facility		0					0			0	0
Variable Term Loan Note Due October 2023 \| Medium-term notes
Debt Instrument [Line Items]
Long-term debt		$ 0					$ 0			$ 0	$ 998,000,000

Debt and Credit Facilities - Contractual Maturities of Financing Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total	$ 26,695	$ 31,402
Senior notes
Debt Instrument [Line Items]
2022	1,500
2023	2,250
2024	1,750
2025	1,750
2026	2,750
Thereafter	15,750
Total	$ 25,750

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References + Details

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Leases - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Lease term extension	15 years
Termination period	one year
Operating lease expense	$ 156	$ 171	$ 162

Leases - Balance Sheet Location Detail (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Right-of-use assets, net	$ 542	$ 646
Lease liabilities - current	101	107
Lease liabilities - noncurrent	$ 489	$ 608
Weighted average remaining lease term	8 years 6 months	8 years 7 months 6 days
Weighted average discount rate	3.00%	3.32%
Operating lease, right-of-use asset, statement of financial position, extensible enumeration	Other long-term assets	Other long-term assets
Operating lease, noncurrent, statement of financial position, extensible enumeration	Other long-term obligations	Other long-term obligations
Operating lease, current, statement of financial position, extensible enumeration	Accrued and other current liabilities	Accrued and other current liabilities

Leases - Supplemental Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities	$ 123	$ 66
Right-of-use assets obtained in exchange for lease liabilities	$ 88	$ 88

Leases - Summary of Operating Lease Liabilities Maturity (Details) $ in Millions	Dec. 31, 2021 USD ($)
Leases [Abstract]
2022	$ 117
2023	108
2024	92
2025	61
2026	50
Thereafter	249
Total undiscounted lease payments	677
Less: imputed interest	87
Total discounted lease payments	$ 590

Commitments and Contingencies (Details) $ in Millions		1 Months Ended			3 Months Ended			12 Months Ended
Commitments and Contingencies (Details) $ in Millions	Feb. 01, 2022	Oct. 31, 2021 patent	Apr. 30, 2020 plaintiff agreement	Dec. 31, 2019 USD ($) patent opposingParty	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) lawsuit plaintiff	Dec. 31, 2016 party
Other Commitments [Line Items]
Number of additional patents allegedly infringed \| patent		2
Number of patents allegedly infringed, scenario two \| patent				2
Number of patents allegedly infringed, scenario one \| patent				4
Purchase commitments, year one						$ 1,100		$ 1,100
Purchase commitments, year two						450		450
Purchase commitments, year three						243		243
Purchase commitments, year four						60		60
Purchase commitments, year five						31		$ 31
ViiV
Other Commitments [Line Items]
Pre-tax charge to cost of goods sold						$ 1,250
ViiV \| Forecast
Other Commitments [Line Items]
Payments for legal settlements					$ 1,250
ViiV \| Subsequent event
Other Commitments [Line Items]
Royalty percentage on future sales	3.00%
Juno
Other Commitments [Line Items]
Amount reversed against previously recorded litigation accrual							$ 175
Damages awarded				$ 585
Running royalty rate from October 2017				27.60%
Enhanced damages on past sales			50.00%
Running royalty rate on future sales			27.60%
Pre-Exposure Prophylaxis
Other Commitments [Line Items]
Number of material transfer agreements \| agreement			4
European Patent Claims 2024 Expiration
Other Commitments [Line Items]
Number of parties appealed \| opposingParty				2
European Patent Claims 2026 Expiration
Other Commitments [Line Items]
Number of parties appealed \| opposingParty				3
European Patent Claims 2032 Expiration
Other Commitments [Line Items]
Number of parties appealed \| opposingParty				3
European Patent Claims 2027 Expiration
Other Commitments [Line Items]
Number of parties appealed \| opposingParty				2
Number of parties filing opposition \| party									3
Product Liability
Other Commitments [Line Items]
Number of claims filed \| lawsuit								1
Number of plaintiffs \| plaintiff								27,000
Qui Tam
Other Commitments [Line Items]
Number of plaintiffs \| plaintiff			2

Stockholders' Equity - Repurchases of Common Stock (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2020	Mar. 31, 2016
Class of Stock [Line Items]
Stock repurchase program, remaining authorized amount	$ 6,300
Amount	$ 546	$ 1,583	$ 1,749
Average price per share (in dollars per share)	$ 66.58	$ 70.64	$ 66.36
2016 stock repurchase program
Class of Stock [Line Items]
Stock repurchase program, authorized amount					$ 12,000
2020 stock repurchase program
Class of Stock [Line Items]
Stock repurchase program, authorized amount				$ 5,000
Publicly announced program
Class of Stock [Line Items]
Shares repurchased and retired (in shares)	8	22	26

Stockholders' Equity - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended								12 Months Ended
	Feb. 01, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Dividend Per Share (in dollars per share)		$ 0.71	$ 0.71	$ 0.71	$ 0.71	$ 0.68	$ 0.68	$ 0.68	$ 0.68	$ 2.84	$ 2.72	$ 2.52
Amount		$ 904	$ 905	$ 903	$ 906	$ 865	$ 866	$ 866	$ 867	$ 3,618	$ 3,464
Subsequent event
Subsequent Event [Line Items]
Dividend Per Share (in dollars per share)	$ 0.73

Stockholders' Equity - Preferred Stock (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Preferred stock, authorized (in shares)	5,000,000	5,000,000
Preferred stock, outstanding (in shares)	0	0

Stockholders' Equity - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 18,221	$ 22,650	$ 21,534
Other comprehensive income (loss)	143	(145)	5
Ending balance	21,064	18,221	22,650
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(60)	85	80
Net unrealized gain	85	(62)	132
Reclassifications to net income	58	(83)	(127)
Other comprehensive income (loss)	143	(145)	5
Ending balance	83	(60)	85
Foreign Currency Translation, Net of Tax
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	51	53	47
Net unrealized gain	(38)	(2)	6
Reclassifications to net income	0	0	0
Other comprehensive income (loss)	(38)	(2)	6
Ending balance	13	51	53
Unrealized Gains and Losses on Available-for-Sale Debt Securities, Net of Tax
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2	1	(52)
Net unrealized gain	(6)	43	54
Reclassifications to net income	0	(42)	(1)
Other comprehensive income (loss)	(6)	1	53
Ending balance	(4)	2	1
Unrealized Gains and Losses on Cash Flow Hedges, Net of Tax
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(113)	31	85
Net unrealized gain	129	(103)	72
Reclassifications to net income	58	(41)	(126)
Other comprehensive income (loss)	187	(144)	(54)
Ending balance	$ 74	$ (113)	$ 31

- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

- Definition

Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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+ Details

Employee Benefits - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Value of stock issued	$ 111	$ 100	$ 90
Matching contribution expense	$ 166	144	110
2004 Plan \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (in shares)	309
Shares available for future grant (in shares)	82
2018 Plan \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (in shares)	12
Immunomedics Plan \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized (in shares)	26
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Intrinsic value of options exercised	$ 48	$ 179	$ 209
Weighted average grant date fair value (in dollars per share)	$ 10.05	$ 11.69	$ 12.15
Unrecognized compensation cost	$ 47
Period for recognition	2 years 3 months 18 days
Stock option \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	3 years
Stock option \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	4 years
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 65.42	70.94	64.31
RSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	3 years
RSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	4 years
PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 71.31	$ 83.64	$ 68.30
PSUs \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	1 year
Payout percentage	0.00%
PSUs \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	2 years
Payout percentage	200.00%
Restricted stock and performance share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 917
Period for recognition	2 years 2 months 12 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grant (in shares)	5
Purchase price of common stock (percent)	85.00%
Issuances under employee stock purchase plan (in shares)	2
Value of stock issued	$ 111
Capital shares reserved for future issuance (in shares)	79
Deferred compensation plan \| Fair value, recurring \| Fair value
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Marketable equity securities	$ 261	$ 218
Fair value at grant date \| Restricted stock and performance share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of vested stock awards as of vesting date	503	479	$ 450
Fair value at vesting date \| Restricted stock and performance share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of vested stock awards as of vesting date	$ 471	$ 459	$ 372

Employee Benefits - Stock Options (Details) - Stock option $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) $ / shares shares
Shares (in millions)
Outstanding, beginning balance (in shares) \| shares	16.6
Granted (in shares) \| shares	3.8
Forfeited (in shares) \| shares	(0.9)
Expired (in shares) \| shares	(1.1)
Exercised (in shares) \| shares	(1.6)
Outstanding, beginning balance (in shares) \| shares	16.8
Exercisable (in shares) \| shares	11.2
Expected to vest, net of estimated forfeitures (in shares) \| shares	5.3
Weighted- Average Exercise Price (in dollars)
Outstanding, beginning balance (in dollars per share) \| $ / shares	$ 69.40
Granted (in dollars per share) \| $ / shares	64.77
Forfeited (in dollars per share) \| $ / shares	67.67
Expired (in dollars per share) \| $ / shares	82.11
Exercised (in dollars per share) \| $ / shares	37.46
Outstanding, ending balance (in dollars per share) \| $ / shares	70.60
Exercisable (in dollars per share) \| $ / shares	72.43
Expected to vest, net of estimated forfeitures (in dollars per share) \| $ / shares	$ 67.01
Weighted-Average Remaining Contractual Term (years)
Outstanding	5 years 4 months 2 days
Exercisable	3 years 8 months 1 day
Expected to vest, net of estimated forfeitures	8 years 7 months 9 days
Aggregate Intrinsic Value (in millions)
Outstanding \| $	$ 101
Exercisable \| $	68
Expected to vest, net of estimated forfeitures \| $	$ 32

Employee Benefits - Restricted Stock and Performance Share Awards (Details) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
RSUs
Shares
Outstanding, beginning balance (in shares)	19.5
Granted (in shares)	11.9
Vested (in shares)	(7.0)
Forfeited (in shares)	(3.5)
Outstanding, ending balance (in shares)	20.9	19.5
Weighted- Average Grant Date Fair Value Per Share
Outstanding, beginning balance (in dollars per share)	$ 69.80
Granted (in dollars per share)	65.42	$ 70.94	$ 64.31
Vested (in dollars per share)	70.30
Forfeited (in dollars per share)	67.77
Outstanding, ending balance (in dollars per share)	$ 67.48	$ 69.80
PSUs
Shares
Outstanding, beginning balance (in shares)	0.6
Granted (in shares)	0.3
Vested (in shares)	(0.1)
Forfeited (in shares)	(0.1)
Outstanding, ending balance (in shares)	0.7	0.6
Weighted- Average Grant Date Fair Value Per Share
Outstanding, beginning balance (in dollars per share)	$ 84.87
Granted (in dollars per share)	71.31	$ 83.64	$ 68.30
Vested (in dollars per share)	88.36
Forfeited (in dollars per share)	78.37
Outstanding, ending balance (in dollars per share)	$ 79.13	$ 84.87

Employee Benefits - Summary of Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in total costs and expenses	$ 635	$ 1,076	$ 636
Income tax effect	(100)	(222)	2
Stock-based compensation expense, net of tax	535	854	638
Stock-based compensation expense	635	643	636
Income tax expense following U.S. Court of Appeals decision			114
Forty Seven, Inc.
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Accelerated stock-based expense		144
Immunomedics, Inc.
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Accelerated stock-based expense		289
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in total costs and expenses	40	109	48
Research and development expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in total costs and expenses	287	462	289
Selling, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense included in total costs and expenses	$ 308	$ 505	$ 299

Employee Benefits - Schedule of Assumptions Used to Calculate the Fair Value of Awards (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	4.40%	4.00%	3.60%
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility:	29.00%	29.00%	27.00%
Expected term in years:	5 years	5 years	5 years 6 months
Risk-free interest rate:	0.80%	0.80%	2.30%
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility:	25.00%	28.00%	27.00%
Expected term in years:	6 months	6 months	6 months
Risk-free interest rate:	0.10%	0.60%	1.80%

Net Income Per Share Attributable to Gilead Common Shareholders - Narrative (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	15	13	14

Net Income Per Share Attributable to Gilead Common Shareholders - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net income attributable to Gilead	$ 6,225	$ 123	$ 5,386
Shares used in per share calculation - basic (in shares)	1,256	1,257	1,270
Dilutive effect of stock options and equivalents (in shares)	6	6	7
Shares used in per share calculation - diluted (in shares)	1,262	1,263	1,277
Net income per share attributable to Gilead common stockholders - basic (in dollars per share)	$ 4.96	$ 0.10	$ 4.24
Net income per share attributable to Gilead common stockholders - diluted (in dollars per share)	$ 4.93	$ 0.10	$ 4.22

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Income Taxes - Schedule of Income (Loss) Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Domestic	$ 8,587	$ 2,505	$ 4,112
Foreign	(309)	(836)	1,048
Income before income taxes	$ 8,278	$ 1,669	$ 5,160

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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+ Details

Income Taxes - Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Federal:
Current	$ (1,776)	$ (1,450)	$ (1,646)
Deferred	250	164	843
Federal income tax expense (benefit), continuing operations	(1,526)	(1,286)	(803)
State:
Current	(228)	(198)	(135)
Deferred	(185)	97	42
State and local income tax expense (benefit), continuing operations	(413)	(101)	(93)
Foreign:
Current	(185)	(155)	(124)
Deferred	47	(38)	1,224
Foreign income tax expense (benefit), continuing operations	(138)	(193)	1,100
Income tax (expense) benefit	$ (2,077)	$ (1,580)	$ 204

Income Taxes - Schedule of Difference Between Provision For Income Taxes and Federal Statutory Income Tax Rate to Income Before Provision for Income Taxes (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	2.50%	4.20%	0.40%
Foreign earnings at different rates	(0.30%)	(10.00%)	2.50%
Research and other credits	(1.60%)	(6.90%)	(1.90%)
US tax on foreign earnings	1.10%	7.20%	4.30%
Foreign-derived intangible income deduction	(0.016)	(0.080)	(0.032)
Deferred tax - intra-entity transfer of intangible assets	(0.70%)	0.60%	(24.00%)
Settlement of tax examinations	(0.70%)	(10.20%)	(2.40%)
Acquired IPR&D and related charges	0.00%	56.20%	0.00%
Changes in valuation allowance	1.50%	6.70%	0.00%
Non-taxable unrealized (gain) loss on investment	1.80%	23.00%	(5.00%)
Other	2.10%	10.90%	4.30%
Effective tax rate	25.10%	94.70%	(4.00%)

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 413	$ 587
Stock-based compensation	117	113
Reserves and accruals not currently deductible	700	444
Excess of tax basis over book basis of intangible assets	1,157	1,177
Upfront and milestone payments	1,310	1,144
Research and other credit carryforwards	249	219
Equity investments	117	116
Liability related to future royalties	274	247
Other, net	292	311
Total deferred tax assets before valuation allowance	4,629	4,358
Valuation allowance	(520)	(398)	$ (217)
Total deferred tax assets	4,109	3,960
Deferred tax liabilities:
Property, plant and equipment	(227)	(202)
Excess of book basis over tax basis of intangible assets	(6,719)	(6,168)
Other	(180)	(202)
Total deferred tax liabilities	(7,126)	(6,572)
Net deferred tax assets (liabilities)	$ (3,017)	$ (2,612)

Income Taxes - Rollforward of Total Unrecognized Tax Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of period	$ 1,614	$ 2,031	$ 1,595
Tax positions related to current year:
Additions	147	121	138
Reductions	0	0	0
Tax positions related to prior years:
Additions	161	398	405
Reductions	(179)	(481)	0
Settlements	(28)	(454)	(104)
Lapse of statute of limitations	(2)	(1)	(3)
Balance, end of period	$ 1,713	$ 1,614	$ 2,031

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)	$ 2,077	$ 1,580	$ (204)
Excess of tax basis over book basis of intangible assets	1,157	1,177
Valuation allowance	520	398	217
Unrecognized tax benefits	800	1,200
Income tax penalties and interest expense	41	(82)	105
Accrued interest and income tax penalties	218	177
Decrease in unrecognized tax benefits that is reasonably possible	100
Accrued repatriation of foreign earnings	4,000	$ 4,500
Accrued repatriation of foreign earnings, expected to be paid	473
Domestic tax authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	250
Tax credit carryforward	8
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	2,800
Tax credit carryforward	$ 768
Intangible Asset Transfer
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)			(1,200)
Excess of tax basis over book basis of intangible assets			$ 1,200