Gilead Sciences (GILD) 10-Q 5 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	Gilead Sciences Inc
Entity Central Index Key	882,095
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Amendment Flag	false
Entity Common Stock, Shares Outstanding		1,467,605,502

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 7,417	$ 10,027
Short-term marketable securities	1,194	101
Accounts receivable, net	5,331	4,635
Inventories	2,039	1,386
Deferred tax assets	833	508
Prepaid taxes	444	391
Prepaid expenses	282	194
Other current assets	553	472
Total current assets	18,093	17,714
Noncurrent Assets
Property, plant and equipment, net	1,899	1,674
Long-term portion of prepaid royalties	428	466
Long-term deferred tax assets	177	236
Long-term marketable securities	6,056	1,598
Intangible assets, net	10,660	11,073
Goodwill	1,172	1,172
Other long-term assets	682	731
Total assets	39,167	34,664
Current liabilities:
Accounts payable	1,571	955
Accrued government and other rebates	4,367	2,316
Accrued compensation and employee benefits	268	316
Income taxes payable	356	105
Other accrued liabilities	1,510	1,452
Deferred revenues	501	134
Current portion of long-term debt and other obligations, net	352	483
Total current liabilities	8,925	5,761
Noncurrent Liabilities
Long-term debt, net	11,922	11,921
Long-term income taxes payable	883	562
Long-term deferred tax liabilities	36	51
Other long-term obligations	$ 760	$ 535
Commitments and Contingencies
Equity Component of Currently Redeemable Convertible Notes
Equity component of currently redeemable convertible notes	$ 7	$ 15
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; shares authorized of 5,600 at June 30, 2015 and December 31, 2014; shares issued and outstanding of 1,473 at June 30, 2015 and 1,499 at December 31, 2014	2	2
Additional paid-in capital	0	2,391
Accumulated other comprehensive income	247	301
Retained earnings	16,038	12,732
Total Gilead stockholders’ equity	16,287	15,426
Noncontrolling interest	347	393
Total stockholders’ equity	16,634	15,819
Total liabilities and stockholders’ equity	$ 39,167	$ 34,664

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (unaudited) Parenthetical - $ / shares	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred Stock, Par Value (usd per share)	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Outstanding	0	0
Common Stock, Par Value (usd per share)	$ 0.001	$ 0.001
Common Stock, Shares Authorized	5,600,000,000	5,600,000,000
Common Stock, Shares Issued	1,473,000,000	1,499,000,000
Common Stock, Shares Outstanding	1,473,000,000	1,499,000,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Product sales	$ 8,126	$ 6,413	$ 15,531	$ 11,284
Royalty, contract and other revenues	118	122	307	250
Total revenues	8,244	6,535	15,838	11,534
Cost of goods sold
Cost of goods sold	998	925	1,880	1,738
Research and development expenses	818	584	1,514	1,179
Selling, general and administrative expenses	812	614	1,457	1,162
Total costs and expenses	2,628	2,123	4,851	4,079
Income from operations	5,616	4,412	10,987	7,455
Interest expense	(140)	(102)	(293)	(178)
Other income (expense), net	35	(4)	56	(22)
Income before provision for income taxes	5,511	4,306	10,750	7,255
Provision for income taxes	1,014	656	1,921	1,382
Net income	4,497	3,650	8,829	5,873
Net income (loss) attributable to noncontrolling interest	5	(6)	4	(10)
Net income attributable to Gilead	$ 4,492	$ 3,656	$ 8,825	$ 5,883
Net income per share attributable to Gilead common stockholders - basic (in dollars per share)	$ 3.05	$ 2.39	$ 5.96	$ 3.83
Shares used in per share calculation - basic (in shares)	1,472	1,533	1,480	1,535
Net income per share attributable to Gilead common stockholders - diluted (in dollars per share)	$ 2.92	$ 2.20	$ 5.68	$ 3.52
Shares used in per share calculation - diluted (in shares)	1,540	1,664	1,555	1,672
Cash dividends declared per share	$ 0.43	$ 0	$ 0.43	$ 0

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 4,497	$ 3,650	$ 8,829	$ 5,873
Other comprehensive income (loss):
Net foreign currency translation gains (losses), net of tax	3	1	(7)	7
Available-for-sale securities:
Net unrealized gains (losses), net of tax impact of $(1), $1, $2 and $1	(3)	1	3	1
Net change	(3)	1	3	1
Cash flow hedges:
Net unrealized gains (losses), net of tax impact of $(3), $(2), $3 and $0	(110)	32	273	33
Reclassifications to net income, net of tax impact of $(5), $(1), $(9) and $(2)	(182)	20	(323)	42
Net change	(292)	52	(50)	75
Other comprehensive income (loss)	(292)	54	(54)	83
Comprehensive income	4,205	3,704	8,775	5,956
Comprehensive income (loss) attributable to noncontrolling interest	5	(6)	4	(10)
Comprehensive income attributable to Gilead	$ 4,200	$ 3,710	$ 8,771	$ 5,966

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income Parenthetical - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Available-for-sale securities:
Net Unrealized Gains, Tax Impact	$ (1)	$ 1	$ 2	$ 1
Cash flow hedges:
Net Unrealized Losses, Tax Impact	(3)	(2)	3	0
Reclassification Adjustments, Tax Impact	$ (5)	$ (1)	$ (9)	$ (2)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities
Net income	$ 8,829	$ 5,873
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities
Depreciation expense	75	53
Amortization expense	467	454
Stock-based compensation expense	188	165
Excess tax benefits from stock-based compensation	(326)	(214)
Tax benefits from exercise and vesting of stock-based awards	326	216
Deferred income taxes	(260)	(53)
Other	27	29
Changes in operating assets and liabilities:
Accounts receivable, net	(810)	(1,332)
Inventories	(634)	(21)
Prepaid expenses and other assets	(127)	(522)
Accounts payable	620	(90)
Income taxes payable	574	298
Accrued liabilities	2,045	877
Deferred revenues	365	20
Net cash provided by operating activities	11,359	5,753
Investing Activities:
Purchases of marketable securities	(6,847)	(650)
Proceeds from sales of marketable securities	1,143	239
Proceeds from maturities of marketable securities	148	18
Capital expenditures	(295)	(255)
Net cash used in investing activities	(5,851)	(648)
Financing Activities:
Proceeds from debt financing, net of issuance costs	0	3,966
Proceeds from convertible note hedges	508	1,312
Purchases of convertible note hedges	0	(26)
Repayments of debt and other obligations	(650)	(2,439)
Payments to settle warrants	(3,865)	0
Proceeds from issuances of common stock	202	163
Repurchases of common stock	(3,901)	(1,650)
Payment of dividend	(633)	0
Excess tax benefits from stock-based compensation	326	214
Net distributions to noncontrolling interest	(50)	(27)
Net cash provided by (used in) financing activities	(8,063)	1,513
Effect of exchange rate changes on cash and cash equivalents	(55)	0
Net change in cash and cash equivalents	(2,610)	6,618
Cash and cash equivalents at beginning of period	10,027	2,113
Cash and cash equivalents at end of period	$ 7,417	$ 8,731

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of Gilead Sciences, Inc. (Gilead, we or us) believes are necessary for a fair presentation of the periods presented. These interim financial results are not necessarily indicative of results expected for the full fiscal year or for any subsequent interim period. The accompanying Condensed Consolidated Financial Statements include the accounts of Gilead, our wholly-owned subsidiaries and certain variable interest entities for which we are the primary beneficiary. For consolidated entities where we own or are exposed to less than 100% of the economics, we record net income (loss) attributable to noncontrolling interests in our Condensed Consolidated Statements of Income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties. All intercompany transactions have been eliminated. The Condensed Consolidated Financial Statements include the results of companies acquired by us from the date of each acquisition for the applicable reporting periods. The accompanying Condensed Consolidated Financial Statements and related Notes to Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the related notes thereto for the year ended December 31, 2014 , included in our Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission. Significant Accounting Policies, Estimates and Judgments The preparation of these Condensed Consolidated Financial Statements 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, management evaluates its 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. Actual results may differ significantly from these estimates. Estimates are assessed each period and updated to reflect current information. 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. The majority of our trade accounts receivable arises from product sales in the United States and Europe. As of June 30, 2015 , our accounts receivable in Southern Europe, specifically Greece, Italy, Portugal and Spain, totaled approximately $1.5 billion , of which $118 million were greater than 120 days past due and $29 million were greater than 365 days past due. To date, we have not experienced significant losses with respect to the collection of our accounts receivable. We believe that our allowance for doubtful accounts was adequate at June 30, 2015 . Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (FASB) issued an accounting standard update which requires presentation of debt issuance costs as a direct deduction from the carrying amount of a recognized debt liability on the balance sheet. The update does not change current guidance on the recognition and measurement of debt issuance costs. This guidance will become effective for us for annual periods beginning after December 15, 2015, and interim periods thereafter. At the time of adoption, we will reclassify debt issuance costs to a liability as a direct deduction from the carrying value of the debt, consistent with the presentation of a debt discount. We do not expect that the adoption of this update will have a material impact on our Condensed Consolidated Financial Statements. In May 2014, the FASB, jointly with the International Accounting Standards Board, issued a comprehensive new standard on revenue recognition from contracts with customers. The standard's core principle is that a reporting entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. On July 9, 2015, the FASB decided to delay the effective date of the new standard by one year. The standard would become effective for us beginning in the first quarter of 2018. Early application would be permitted in 2017. Entities would have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. We are currently evaluating the impact of our adoption of this standard on our Condensed Consolidated Financial Statements.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2015
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [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 which include quoted prices in active markets for identical assets or liabilities; • Level 2 inputs which 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. 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; and • Level 3 inputs which 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 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 principally of cash and cash equivalents, marketable securities, accounts receivable, foreign currency exchange contracts, accounts payable and short-term and long-term debt. Cash and cash equivalents, marketable securities and foreign currency exchange contracts that hedge accounts receivable and forecasted sales are reported at their respective fair values on our Condensed Consolidated Balance Sheets. Short-term and long-term debt are reported at their amortized cost on our Condensed Consolidated Balance Sheets. The remaining financial instruments are reported on our Condensed Consolidated Balance Sheets at amounts that approximate current fair values. The following table summarizes the assets and liabilities measured at fair value on a recurring basis, by level, within the fair value hierarchy (in millions): June 30, 2015 December 31, 2014 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Money market funds $ 5,594 $ — $ — $ 5,594 $ 7,926 $ — $ — $ 7,926 Corporate debt securities — 3,435 — 3,435 — 938 — 938 U.S. treasury securities 2,085 — — 2,085 363 — — 363 Residential mortgage and asset-backed securities — 914 — 914 — 269 — 269 Certificates of deposit — 361 — 361 — — — — Foreign currency derivative contracts — 342 — 342 — 349 — 349 U.S. government agencies securities — 293 — 293 — 113 — 113 Non-U.S. government securities — 169 — 169 — — — — Municipal debt securities — 43 — 43 — 16 — 16 Deferred compensation plan 63 — — 63 54 — — 54 $ 7,742 $ 5,557 $ — $ 13,299 $ 8,343 $ 1,685 $ — $ 10,028 Liabilities: Contingent consideration $ — $ — $ 140 $ 140 $ — $ — $ 133 $ 133 Deferred compensation plan 63 — — 63 54 — — 54 Foreign currency derivative contracts — 39 — 39 — — — — $ 63 $ 39 $ 140 $ 242 $ 54 $ — $ 133 $ 187 Level 2 Inputs We estimate the fair values of our corporate debt securities, residential mortgage and asset-backed securities, government related securities and certificates of deposit by taking into consideration valuations obtained from third-party pricing services. The pricing services utilize industry standard valuation models, including both income- and market-based approaches, for which all significant inputs are observable, either directly or indirectly, to estimate 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. Substantially all of our foreign currency derivative contracts have maturities primarily over an 18-month time horizon and all are with counterparties that have a minimum credit rating of A- or equivalent by Standard & Poor's, Moody's Investors Service, Inc. or Fitch, Inc. We estimate the fair values of these contracts by taking into consideration 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 rates, London Interbank Offered Rates (LIBOR) and swap rates. These inputs, where applicable, are at commonly quoted intervals. The fair values of our convertible senior notes and senior unsecured notes were determined using Level 2 inputs based on their quoted market values. The following table summarizes the carrying values and fair values of our convertible senior notes and senior unsecured notes (in millions): June 30, 2015 December 31, 2014 Type of Borrowing Description Carrying Value Fair Value Carrying Value Fair Value Convertible Senior May 2016 Notes $ 352 $ 1,851 $ 483 $ 2,097 Senior Unsecured April 2021 Notes 995 1,094 995 1,108 Senior Unsecured December 2016 Notes 700 720 700 727 Senior Unsecured December 2021 Notes 1,248 1,366 1,248 1,377 Senior Unsecured December 2041 Notes 998 1,152 998 1,229 Senior Unsecured April 2019 Notes 499 501 499 500 Senior Unsecured April 2024 Notes 1,748 1,789 1,747 1,836 Senior Unsecured April 2044 Notes 1,747 1,809 1,747 1,954 Senior Unsecured February 2020 Notes 499 502 499 504 Senior Unsecured February 2025 Notes 1,748 1,759 1,748 1,797 Senior Unsecured February 2045 Notes 1,740 1,735 1,740 1,872 Level 3 Inputs As of June 30, 2015 and December 31, 2014 , the only assets or liabilities that were measured using Level 3 inputs were contingent consideration liabilities of $140 million and $133 million . 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. The contingent consideration liabilities included the potential future contingent consideration payments resulting from the acquisition of Arresto Biosciences, Inc. for royalty obligations on future sales once specified sales-based milestones are achieved, and the acquisitions of CGI Pharmaceuticals, Inc. and Calistoga Pharmaceuticals, Inc. upon achievement of development or regulatory approval-based milestones.

Available-for-Sale Securities

Available-for-Sale Securities	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Available-for-Sale Securities	AVAILABLE-FOR-SALE SECURITIES Estimated fair values of available-for-sale securities are generally based on prices obtained from commercial pricing services. The following table is a summary of available-for-sale securities recorded in cash and cash equivalents or marketable securities in our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 December 31, 2014 Amortized Gross Gross Estimated Amortized Gross Gross Estimated Money market funds $ 5,594 $ — $ — $ 5,594 $ 7,926 $ — $ — $ 7,926 Corporate debt securities 3,438 2 (5 ) 3,435 941 — (3 ) 938 U.S. treasury securities 2,083 2 — 2,085 363 — — 363 Residential mortgage and asset-backed securities 914 1 (1 ) 914 269 — — 269 Certificates of deposit 361 — — 361 — — — — U.S. government agencies securities 293 — — 293 113 — — 113 Non-U.S. government securities 169 — — 169 — — — — Municipal debt securities 43 — — 43 16 — — 16 Total $ 12,895 $ 5 $ (6 ) $ 12,894 $ 9,628 $ — $ (3 ) $ 9,625 The following table summarizes the classification of the available-for-sale securities on our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 December 31, 2014 Cash and cash equivalents $ 5,644 $ 7,926 Short-term marketable securities 1,194 101 Long-term marketable securities 6,056 1,598 Total $ 12,894 $ 9,625 Cash and cash equivalents in the table above exclude cash of $1.8 billion as of June 30, 2015 and $2.1 billion as of December 31, 2014 . The following table summarizes our portfolio of available-for-sale securities by contractual maturity (in millions): June 30, 2015 Amortized Cost Fair Value Less than one year $ 6,838 $ 6,838 Greater than one year but less than five years 5,999 5,998 Greater than five years but less than ten years 34 34 Greater than ten years 24 24 Total $ 12,895 $ 12,894 The following table summarizes our available-for-sale debt securities that were in a continuous unrealized loss position, but were not deemed to be other-than-temporarily impaired (in millions): Less Than 12 Months 12 Months or Greater Total Gross Estimated Gross Estimated Gross Estimated June 30, 2015 Corporate debt securities $ (5 ) $ 2,101 $ — $ 21 $ (5 ) $ 2,122 Residential mortgage and asset-backed securities (1 ) 499 — 16 (1 ) 515 U.S. treasury securities — 378 — — — 378 U.S. government agencies securities — 100 — — — 100 Non-U.S. government securities — 151 — — — 151 Municipal debt securities — 13 — — — 13 Total $ (6 ) $ 3,242 $ — $ 37 $ (6 ) $ 3,279 December 31, 2014 Corporate debt securities $ (3 ) $ 802 $ — $ — $ (3 ) $ 802 Residential mortgage and asset-backed securities — 227 — 1 — 228 U.S. treasury securities — 206 — — — 206 U.S. government agencies securities — 22 — — — 22 Municipal debt securities — 2 — — — 2 Total $ (3 ) $ 1,259 $ — $ 1 $ (3 ) $ 1,260 We held a total of 1,034 positions as of June 30, 2015 and 468 positions as of December 31, 2014 that were in an unrealized loss position. The unrealized losses were immaterial both individually and in aggregate. We did not record any other-than-temporary impairments on these securities as of June 30, 2015 , because we do not intend to sell these securities nor do we believe that we will be required to sell them before they recover their amortized costs at maturity.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Jun. 30, 2015
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, the most significant of which is the Euro. In order to manage this risk, 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 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 unrecognized 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 of our foreign subsidiaries 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 Condensed 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 maturity dates of 18 months or less. Upon executing a hedging contract and quarterly thereafter, we assess prospective hedge effectiveness using regression analysis which calculates the change in cash flow as a result of the hedge instrument. On a monthly basis, we assess retrospective hedge effectiveness using a dollar offset approach. We exclude time value from our effectiveness testing and recognize changes in the time value of the hedge in other income (expense), net. The effective component of our hedge is recorded as an unrealized gain or loss on the hedging instrument in accumulated other comprehensive income (OCI) within stockholders' equity. When the hedged forecasted transaction occurs, the hedge is de-designated and the unrealized gains or losses are reclassified into product sales. The majority of gains and losses related to the hedged forecasted transactions reported in accumulated OCI at June 30, 2015 will be reclassified to product sales within 12 months. The cash flow effects of our derivative contracts for the six months ended June 30, 2015 and 2014 are included within net cash provided by operating activities in the Condensed Consolidated Statements of Cash Flows. We had notional amounts on foreign currency exchange contracts outstanding of $6.8 billion at June 30, 2015 and $6.4 billion at December 31, 2014 . While all of our derivative contracts allow us the right to offset assets or liabilities, we have presented amounts on a gross basis. Under the International Swap Dealers Association, Inc. master agreements with the respective counterparties of the foreign currency exchange contracts, subject to applicable requirements, we are allowed to net settle transactions of the same currency with a single net amount payable by one party to the other. The following table summarizes the classification and fair values of derivative instruments on our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 Asset Derivatives Liability Derivatives Classification Fair Value Classification Fair Value Derivatives designated as hedges: Foreign currency exchange contracts Other current assets $ 340 Other accrued liabilities $ (29 ) Foreign currency exchange contracts Other long-term assets 2 Other long-term obligations (10 ) Total derivatives $ 342 $ (39 ) December 31, 2014 Asset Derivatives Liability Derivatives Classification Fair Value Classification Fair Value Derivatives designated as hedges: Foreign currency exchange contracts Other current assets $ 314 Other accrued liabilities $ — Foreign currency exchange contracts Other long-term assets 35 Other long-term obligations — Total derivatives $ 349 $ — The following table summarizes the effect of our foreign currency exchange contracts on our Condensed Consolidated Financial Statements (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Derivatives designated as hedges: Gains (losses) recognized in accumulated OCI (effective portion) $ (113 ) $ 30 $ 276 $ 33 Gains (losses) reclassified from accumulated OCI into product sales (effective portion) $ 187 $ (19 ) $ 332 $ (40 ) Gains (losses) recognized in other income (expense), net (ineffective portion and amounts excluded from effectiveness testing) $ 6 $ (4 ) $ 7 $ (4 ) Derivatives not designated as hedges: Gains (losses) recognized in other income (expense), net $ (40 ) $ 8 $ 68 $ 9 From time to time, we may discontinue cash flow hedges and as a result, record related amounts in other income (expense), net on our Condensed Consolidated Statements of Income. There were no material amounts recorded in other income (expense), net for the three and six months ended June 30, 2015 and 2014 as a result of the discontinuance of cash flow hedges. As of June 30, 2015 and December 31, 2014 , we held one type of financial instrument, derivative contracts related to foreign currency exchange contracts. The following table summarizes the potential effect of offsetting derivatives by type of financial instrument on our Condensed Consolidated Balance Sheets (in millions): As of June 30, 2015 Offsetting of Derivative Assets/Liabilities Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet Description Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheet Amounts of Assets/Liabilities Presented in the Condensed Consolidated Balance Sheet Derivative Financial Instruments Cash Collateral Received/Pledged Net Amount (Legal Offset) Derivative assets $ 342 $ — $ 342 $ (38 ) $ — $ 304 Derivative liabilities (39 ) — (39 ) 38 — (1 ) As of December 31, 2014 Offsetting of Derivative Assets/Liabilities Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet Description Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheet Amounts of Assets/Liabilities Presented in the Condensed Consolidated Balance Sheet Derivative Financial Instruments Cash Collateral Received/Pledged Net Amount (Legal Offset) Derivative assets $ 349 $ — $ 349 $ — $ — $ 349 Derivative liabilities — — — — — —

Inventories

Inventories	6 Months Ended
	Jun. 30, 2015
Inventory Disclosure [Abstract]
Inventories	INVENTORIES Inventories are summarized as follows (in millions): June 30, 2015 December 31, 2014 Raw materials $ 1,206 $ 909 Work in process 706 500 Finished goods 592 466 Total $ 2,504 $ 1,875 Reported as: Inventories $ 2,039 $ 1,386 Other long-term assets 465 489 Total $ 2,504 $ 1,875 Amounts reported as other long-term assets primarily consisted of raw materials as of June 30, 2015 and December 31, 2014 . The joint venture formed by Gilead Sciences, LLC and Bristol-Myers Squibb Company (BMS) (See Note 7, Collaborative Arrangements), which is included in our Condensed Consolidated Financial Statements, held efavirenz active pharmaceutical ingredient in inventory. This efavirenz inventory was purchased from BMS at BMS's estimated net selling price of efavirenz and totaled $1.4 billion as of June 30, 2015 and $806 million as of December 31, 2014 .

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	INTANGIBLE ASSETS The following table summarizes the carrying amounts of our intangible assets (in millions): June 30, 2015 December 31, 2014 Finite-lived intangible assets $ 10,228 $ 10,641 Indefinite-lived intangible assets 432 432 Total intangible assets $ 10,660 $ 11,073 Finite-Lived Intangible Assets The following table summarizes our finite-lived intangible assets (in millions): June 30, 2015 December 31, 2014 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible asset - sofosbuvir $ 10,720 $ 1,106 $ 10,720 $ 757 Intangible asset - Ranexa 688 320 688 277 Other 455 209 455 188 Total $ 11,863 $ 1,635 $ 11,863 $ 1,222 Amortization expense related to finite-lived intangible assets included primarily in cost of goods sold on our Condensed Consolidated Statements of Income totaled $207 million and $413 million for the three and six months ended June 30, 2015 and $200 million and $399 million for the three and six months ended June 30, 2014 . As of June 30, 2015 , the estimated future amortization expense associated with our finite-lived intangible assets for the remaining six months of 2015 and each of the five succeeding fiscal years is as follows (in millions): Fiscal Year Amount 2015 (remaining six months) $ 413 2016 832 2017 846 2018 853 2019 741 2020 713 Total $ 4,398 Indefinite-Lived Intangible Assets The following table summarizes our indefinite-lived intangible assets as of June 30, 2015 and December 31, 2014 (in millions): Amount Indefinite-lived intangible asset - momelotinib (formerly CYT387) $ 308 Indefinite-lived intangible assets - Other 117 425 Foreign currency translation adjustment 7 Total $ 432

Collaborative Arrangements

Collaborative Arrangements	6 Months Ended
	Jun. 30, 2015
Collaborative Arrangements [Abstract]
Collaborative Arrangements	COLLABORATIVE ARRANGEMENTS We enter into collaboration arrangements with third parties for the development and commercialization of certain products. Both parties 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. Collaboration arrangements are assessed at their inception, and at each reporting date to determine whether we are the primary beneficiary of an entity determined to be a variable interest entity (VIE) and therefore would be required to consolidate the third party. For VIEs, we may be required to consolidate an entity if the contractual terms of the arrangement essentially provide us with control over the entity, even if we do not have a majority voting interest. We assess whether we are the primary beneficiary of a VIE 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. As such, we have consolidated those entities in our consolidated financial statements. As of June 30, 2015 , the only material VIE was our North America joint venture with BMS which is described below. Bristol-Myers Squibb Company North America In 2004, we entered into a collaboration arrangement with BMS to develop and commercialize a single tablet regimen containing our Truvada and BMS's Sustiva (efavirenz) in the United States. This combination was approved for use in the United States in 2006 and is sold under the brand name Atripla. We and BMS structured this collaboration as a joint venture that operates as a limited liability company named Bristol-Myers Squibb & Gilead Sciences, LLC, which we consolidate. We and BMS granted royalty free sublicenses to the joint venture for the use of our respective company owned technologies and, in return, were granted a license by the joint venture to use any intellectual property that results from the collaboration. In 2006, we and BMS amended the joint venture's collaboration agreement to allow the joint venture to sell Atripla in Canada. The economic interests of the joint venture held by us and BMS (including a share of revenues and out-of-pocket expenses) are based on the portion of the net selling price of Atripla attributable to efavirenz and Truvada. Since the net selling price for Truvada may change over time relative to the net selling price of efavirenz, both our and BMS's respective economic interests in the joint venture may vary annually. We and BMS shared marketing and sales efforts. Starting in the second quarter of 2011, except for a limited number of activities that will be jointly managed, the parties no longer coordinate detailing and promotional activities in the United States, and the parties reduced their joint promotional efforts since we launched Complera in August 2011 and Stribild in August 2012. The parties will continue to collaborate on activities such as manufacturing, regulatory, compliance and pharmacovigilance. The daily operations of the joint venture are governed by four primary joint committees formed by both BMS and Gilead. We are responsible for accounting, financial reporting, tax reporting, manufacturing and product distribution for the joint venture. Both parties provide their respective bulk active pharmaceutical ingredients to the joint venture at their approximate market values. The agreement will continue until terminated by the mutual agreement of the parties. In addition, either party may terminate the other party's participation in the collaboration within 30 days after the launch of at least one generic version of such other party's single agent products (or the double agent products). The terminating party then has the right to continue to sell Atripla and become the continuing party, but will be obligated to pay the terminated party certain royalties for a three-year period following the effective date of the termination. As of June 30, 2015 and December 31, 2014 , the joint venture held efavirenz active pharmaceutical ingredient which it purchased from BMS at BMS's estimated net selling price of efavirenz in the U.S. market. These amounts were primarily included in inventories on our Condensed Consolidated Balance Sheets. Selected financial information for the joint venture was as follows (in millions): June 30, 2015 December 31, 2014 Total assets $ 2,751 $ 2,138 Cash and cash equivalents 245 250 Accounts receivable, net 279 297 Inventories 2,225 1,590 Total liabilities 1,910 1,157 Accounts payable 1,501 749 Other accrued liabilities 408 408 These asset and liability amounts do not reflect the impact of intercompany eliminations that are included in our Condensed Consolidated Balance Sheets. Although we consolidate the joint venture, the legal structure of the joint venture limits the recourse that its creditors will have over our general credit or assets. Similarly, the assets held in the joint venture can be used only to settle obligations of the joint venture. Europe In 2007, Gilead Sciences Ireland Unlimited Company, our wholly-owned subsidiary, and BMS entered into a collaboration agreement with BMS which sets forth the terms and conditions under which we and BMS commercialize and distribute Atripla in the European Union (EU), Iceland, Liechtenstein, Norway and Switzerland (collectively, the European Territory). The parties formed a limited liability company which we consolidate, to manufacture Atripla for distribution in the European Territory using efavirenz that it purchases from BMS at BMS's estimated net selling price of efavirenz in the European Territory. We are responsible for manufacturing, product distribution, inventory management and warehousing. Through our local subsidiaries, we have primary responsibility for order fulfillment, collection of receivables, customer relations and handling of sales returns in all the territories where we and BMS promote Atripla. In general, the parties share revenues and out-of-pocket expenses in proportion to the net selling prices of the components of Atripla, Truvada and efavirenz. Starting in 2012, except for a limited number of activities that will be jointly managed, the parties no longer coordinate detailing and promotional activities in the region. We are responsible for accounting, financial reporting and tax reporting for the collaboration. As of June 30, 2015 and December 31, 2014 , efavirenz purchased from BMS at BMS's estimated net selling price of efavirenz in the European Territory is included in inventories on our Condensed Consolidated Balance Sheets. The parties also formed a limited liability company to hold the marketing authorization for Atripla in Europe. We have primary responsibility for regulatory activities. In the major market countries, both parties have agreed to independently continue to use commercially reasonable efforts to promote Atripla. The agreement will terminate upon the expiration of the last-to-expire patent which affords market exclusivity to Atripla or one of its components in the European Territory. In addition, since December 31, 2013, either party may terminate the agreement for any reason and such termination will be effective two calendar quarters after notice of termination. The non-terminating party has the right to continue to sell Atripla and become the continuing party, but will be obligated to pay the terminating party certain royalties for a three-year period following the effective date of the termination. In the event the continuing party decides not to sell Atripla, the effective date of the termination will be the date Atripla is withdrawn in each country or the date on which a third party assumes distribution of Atripla, whichever is earlier.

Debt and Credit Facility

Debt and Credit Facility	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Debt and Credit Facility	DEBT AND CREDIT FACILITY Financing Arrangements The following table summarizes the carrying amounts of our borrowings under various financing arrangements (in millions): Type of Borrowing Description Issue Date Due Date Interest Rate June 30, December 31, 2014 Convertible Senior May 2016 Notes July 2010 May 2016 1.625% $ 352 $ 483 Senior Unsecured April 2021 Notes March 2011 April 2021 4.50% 995 995 Senior Unsecured December 2016 Notes December 2011 December 2016 3.05% 700 700 Senior Unsecured December 2021 Notes December 2011 December 2021 4.40% 1,248 1,248 Senior Unsecured December 2041 Notes December 2011 December 2041 5.65% 998 998 Senior Unsecured April 2019 Notes March 2014 April 2019 2.05% 499 499 Senior Unsecured April 2024 Notes March 2014 April 2024 3.70% 1,748 1,747 Senior Unsecured April 2044 Notes March 2014 April 2044 4.80% 1,747 1,747 Senior Unsecured February 2020 Notes November 2014 February 2020 2.35% 499 499 Senior Unsecured February 2025 Notes November 2014 February 2025 3.50% 1,748 1,748 Senior Unsecured February 2045 Notes November 2014 February 2045 4.50% 1,740 1,740 Total debt, net 12,274 12,404 Less current portion 352 483 Total long-term debt, net $ 11,922 $ 11,921 Convertible Senior Notes During the six months ended June 30, 2015 , a portion of our convertible senior notes due in May 2016 (the May 2016 Notes) was settled and we repaid $140 million of principal balance related to these notes. We also paid $508 million in cash related to the conversion spread of the May 2016 Notes, which represents the conversion value in excess of the principal amount, and received $508 million in cash from the convertible note hedges related to the May 2016 Notes. The initial conversion rate for the May 2016 Notes was 44.0428 shares per $1,000 principal amount (which represented an initial conversion price of approximately $22.71 per share). As of June 30, 2015, the conversion rate was 44.2023 (which represented a conversion price of approximately $22.62 per share). The adjustment to the conversion rate was due to a declaration of a dividend in the second quarter of 2015. As of June 30, 2015 and December 31, 2014 , the May 2016 Notes were classified as current given that their conversion criteria had been met. As a result, the related unamortized discount of $7 million and $15 million , as of June 30, 2015 and December 31, 2014 , respectively, were classified as equity component of currently redeemable convertible notes on our Condensed Consolidated Balance Sheets. As of December 31, 2014, there were 55 million shares of our common stock underlying our warrants expiring in 2016 (the 2016 Warrants). Under the terms of the original agreements, the 2016 Warrants had a strike price of $30.05 per share and were due to expire during the 40 trading-day period commencing August 1, 2016. During the second quarter of 2015, we entered into modified agreements with our warrant counterparties which changed the timing of the expiration for 46 million of our 2016 Warrants. The modified agreements allowed us to settle the 46 million warrants at our option, in cash or shares. According to the terms of the modified agreements, these warrants expired during a 32 trading-day period which commenced on May 11, 2015 and ended on June 24, 2015. We exercised our option to settle in cash, and as a result, paid $3.9 billion as the market value of our common stock at the time of the exercise of the warrants exceeded their strike prices. Because these warrants could have been settled at our option, in cash or shares of common stock, under both the original and the modified agreements and these contracts met all of the applicable criteria for equity classification, the settlement payments were recorded as a reduction to additional paid-in capital on our Condensed Consolidated Balance Sheet. As additional paid-in capital was reduced to zero, the remainder of the warrants settlement was recorded as a reduction in retained earnings. Please see Note 10, Stockholders' Equity for additional information. As of June 30, 2015, 9 million of the 2016 Warrants remained outstanding and have a strike price of $29.62 per share and are due to expire during the 40 trading-day period commencing August 1, 2016. The change to the strike price was due to a declaration of a dividend in the second quarter of 2015. There were no other changes in terms for the remaining 9 million 2016 Warrants. Credit Facility There were no amounts outstanding under the revolving credit facility credit agreement as of June 30, 2015 . We are required to comply with certain covenants under the credit agreement and note indentures and as of June 30, 2015 , we were not in violation of any covenants.

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES We are a party to various legal actions. The most significant of these are described below. It is not possible to determine the outcome of these matters, and we cannot reasonably estimate the maximum potential exposure or the range of possible loss. Litigation Related to Sofosbuvir In January 2012, we acquired Pharmasset, Inc. (Pharmasset). Through the acquisition, we acquired sofosbuvir, a nucleotide analog that acts to inhibit the replication of the hepatitis C virus (HCV). In December 2013, we received U.S. Food and Drug Administration (FDA) approval of sofosbuvir, now known commercially as Sovaldi. In October 2014, we also received approval of the fixed-dose combination of ledipasvir and sofosbuvir, now known commercially as Harvoni. We have received a number of contractual and intellectual property 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 own patents and patent applications that claim sofosbuvir (Sovaldi) as a chemical entity and its metabolites and the fixed-dose combination of ledipasvir and sofosbuvir (Harvoni). Third parties may have, or may obtain rights to, patents that allegedly could be used to prevent or attempt to prevent us from commercializing Sovaldi or Harvoni. For example, we are aware of patents and patent applications owned by other parties that have been or may in the future be alleged by such parties to cover the use of Sovaldi and Harvoni. We cannot predict the ultimate outcome of intellectual property claims related to Sovaldi or Harvoni. We have spent, and will continue to spend, significant resources defending against these claims. If third parties successfully obtain valid and enforceable patents, and successfully prove infringement of those patents by Sovaldi and/or Harvoni, we could be prevented from selling these products unless we were able to obtain a license under such patents. Such a license may not be available on commercially reasonable terms or at all. Interference Proceedings and Litigation with Idenix Pharmaceuticals, Inc. (Idenix) In February 2012, we received notice that the U.S. Patent and Trademark Office (USPTO) had declared Interference No. 105,871 (First Idenix Interference) between our U.S. Patent No. 7,429,572 (the ’572 patent) and Idenix's pending U.S. Patent Application No. 12/131,868. An interference is an administrative proceeding before the USPTO designed to determine who was the first to invent the subject matter claimed by both parties. On January 29, 2014, the USPTO Patent Trial and Appeal Board (PTAB) determined that Pharmasset and not Idenix was the first to invent the compounds in dispute and accordingly Gilead prevailed in the First Idenix Interference. Idenix has appealed the PTAB’s decisions to the U.S. District Court for the District of Delaware. In December 2013, after receiving our request to do so, the USPTO declared Interference No. 105,981 (Second Idenix Interference) between our pending U.S. Patent Application No. 11/854,218 and Idenix’s U.S. Patent No. 7,608,600 (the ’600 patent). The ’600 patent includes claims directed to methods of treating HCV with nucleoside compounds similar to those which were involved in the First Idenix Interference. The purpose of the Second Idenix Interference was to determine who was first to invent the claimed methods of treating HCV with compounds similar to those which were involved in the First Idenix Interference. On March 23, 2015, the PTAB determined that Pharmasset and not Idenix was the first to invent the claimed methods of treating HCV. Idenix appealed this decision in both the U.S. District Court for the District of Delaware and the U.S. Court of Appeal for the Federal Circuit (CAFC). We have filed a motion to dismiss the appeal in Delaware and will respond to the appeal filed in the CAFC. We believe that the Idenix claims involved in the First and Second Idenix Interferences, and similar U.S. and foreign patents claiming the same compounds, metabolites and uses thereof, are invalid. As a result, we filed an Impeachment Action in the Federal Court of Canada to invalidate Idenix Canadian Patent No. 2,490,191 (the ’191 patent), which is the Canadian patent that corresponds to the ’600 patent and the Idenix patent application that was the subject of the First Idenix Interference. Idenix has asserted that the commercialization of Sovaldi in Canada will infringe its ’191 patent and that our Canadian Patent No. 2,527,657, corresponding to the ’572 patent involved in the First Idenix Interference, is invalid. A trial on these issues was held in January and February 2015 and we are awaiting a decision. We filed a similar legal action in Norway in the Oslo District Court seeking to invalidate Idenix's Norwegian patent corresponding to the ’600 patent. In September 2013, Idenix filed an invalidation action in the Norwegian proceedings against our Norwegian Patent No. 333700 patent, which corresponds to the ’572 patent. On March 21, 2014, the Norwegian court found all claims in the Idenix Norwegian patent to be invalid and upheld the validity of all claims in the challenged Gilead patent. On April 30, 2014, Idenix appealed the March 21, 2014 decision to the Norwegian Court of Appeal. The appeal hearing from the March 2014 decision is scheduled for February 2016. In January 2013, we filed a legal action in the Federal Court of Australia seeking to invalidate Idenix’s Australian patent corresponding to the ’600 patent. In April 2013, Idenix asserted that the commercialization of Sovaldi in Australia will infringe its Australian patent corresponding to the ’600 patent. A trial on these issues is scheduled to commence in September 2015 in Sydney. On March 12, 2014 the European Patent Office (EPO) granted Idenix European Patent No. 1 523 489 (the ’489 patent), which corresponds to the ’600 patent. The same day that the ’489 patent was granted, we filed an opposition with the EPO seeking to revoke the ’489 patent. Also on that day, Idenix initiated infringement proceedings against Gilead in the United Kingdom (UK), Germany and France alleging that the commercialization of Sovaldi would infringe the UK, German and French counterparts of the ’489 patent. A trial was held in the UK in October 2014 to determine the issues of infringement and validity of the Idenix UK patent. In December 2014, the High Court of Justice of England and Wales (UK Court) invalidated all challenged claims of the ’489 patent on multiple grounds. The UK Court has granted Idenix permission to appeal the December 1, 2014 judgment. On March 12, 2015, the German court in Düsseldorf determined that the Idenix patent was highly likely to be invalid and stayed the infringement proceedings pending the outcome of the opposition filed in the EPO. Idenix has not appealed this decision of the German court staying the proceedings. Upon Idenix's request, the French proceedings have been stayed. Idenix has not been awarded patents corresponding to the ’600 patent in Japan or China. In the event such patents are issued, we expect to challenge them in proceedings similar to those we invoked in other countries. In December 2013, Idenix, Universita Degli Studi di Cagliari (UDSG), Centre National de la Recherche Scientifique and L’Université Montpellier II sued us in U.S. District Court for the District of Delaware alleging that the commercialization of sofosbuvir will infringe the ’600 patent and that an interference exists between the ’600 patent and our U.S. Patent No. 8,415,322. Also in December 2013, Idenix and UDSG sued us in the U.S. District Court for the District of Massachusetts alleging that the commercialization of sofosbuvir will infringe U.S. Patent Nos. 6,914,054 and 7,608,597. On June 30, 2014, the court transferred the Massachusetts litigation to the U.S. District Court for the District of Delaware. The district court has set trial dates in October 2016 and December 2016 for resolution of these issues. A decision by the district court may be appealed by either party to the CAFC. Idenix was acquired by Merck in August 2014. While the acquisition does not change our view of the lack of merit in the claims made by Idenix, Merck has greater resources than Idenix and may therefore choose to fund the litigation at higher levels than Idenix. Litigation with Merck In August 2013, Merck contacted us requesting that we pay royalties on the sales of sofosbuvir and obtain a license to U.S. Patent Nos. 7,105,499 and 8,481,712, which it co-owns with Isis Pharmaceuticals, Inc. In August 2013, we filed a lawsuit in the U.S. District Court for the Northern District of California seeking a declaratory judgment that the Merck patents are invalid and not infringed. Merck’s U.S. Patent Nos. 7,105,499 and 8,481,712 cover compounds which do not include, but may relate to, sofosbuvir. During patent prosecution, Merck amended its patent application in an attempt to cover compounds related to sofosbuvir. If the court determines that Merck’s patents are valid and that we have infringed those claims, we may be required to obtain a license from and pay royalties to Merck to commercialize sofosbuvir. Either party may appeal a decision by the District Court to the CAFC. The court has set a trial date of March 7, 2016 for this lawsuit. Litigation with AbbVie, Inc. (AbbVie) AbbVie has obtained U.S. Patent Nos. 8,466,159, 8,492,386, 8,680,106, 8,685,984, and 8,809,265 (AbbVie Patents) which purport to cover the use of a fixed dose combination of ledipasvir and sofosbuvir (LDV/SOF), now known commercially as Harvoni for the treatment of HCV. Gilead is aware that AbbVie has pending patent applications in the United States and granted and pending applications in other countries. We own published and pending patent applications directed to the use of combinations for the treatment of HCV, and, specifically, to the combination of ledipasvir and sofosbuvir. Certain of our applications were filed before the AbbVie Patents. For this reason and others, we believe the AbbVie Patents are invalid. Accordingly, in December 2013, we filed a lawsuit in the U.S. District Court for the District of Delaware seeking declaratory judgment that the AbbVie Patents are invalid and unenforceable, as well as other relief. We believe that Abbott Laboratories, Inc. and AbbVie conspired to eliminate competition in the HCV market by falsely representing to the USPTO that they, and not Gilead, invented methods of treating HCV using a combination of LDV/SOF. In February and March 2014, AbbVie responded to our lawsuit by also filing two lawsuits in the U.S. District Court for the District of Delaware alleging that our fixed-dose combination of LDV/SOF will infringe its patents. All of those lawsuits have been consolidated into a single action. In the United States, either party may appeal a decision by the District Court to the CAFC. The AbbVie Patents have not blocked or delayed the commercialization of our combination product in the United States, Canada, or Europe. We do not expect any other foreign patents to block or delay the commercialization around the world. The court has set a trial date of September 12, 2016 for this lawsuit. Additionally, AbbVie has obtained U.S. Patent No. 9,034,832 which purports to cover a solid oral dosage form containing ledipasvir. Accordingly, in May 2015, we filed a lawsuit in the U.S. District Court for the District of Delaware seeking declaratory judgment that AbbVie’s patent is invalid, as well as other relief. We do not expect AbbVie’s patent to block the commercialization of our combination product. No trial date has been set. If a court determines that the AbbVie Patents are valid and that we have infringed those claims, we may be required to obtain a license from and pay royalties to AbbVie to commercialize sofosbuvir combination products. European Patent Claims In February 2015, several parties filed oppositions in the EPO requesting revocation of our granted European patent covering sofosbuvir that expires in 2028. While we are confident in the strength of our sofosbuvir patent, we cannot predict the ultimate outcome of these actions. 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 in Europe could be substantially shortened or eliminated entirely. If the sofosbuvir patent is revoked, and no other European patents are granted covering sofosbuvir, our exclusivity will be based entirely on regulatory exclusivity granted by the European Medicines Agency (EMA). Sovaldi has been granted regulatory exclusivity that will prevent generic sofosbuvir from entering the EU for 10 years following approval of Sovaldi, or January 2024. If we lose exclusivity for Sovaldi prior to 2028, our expected revenues and results of operation could be negatively impacted for the years including and succeeding the year in which such exclusivity is lost. Litigation with Generic Manufacturers As part of the approval process for some of our products, the 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 these products earlier than their patent expiration would have a significant negative effect on our revenues and results of operations. Current legal proceedings of significance with some of our generic manufacturers include: Mylan In April 2014, we received notice that Mylan Inc. (Mylan) submitted an ANDA to the FDA requesting permission to manufacture and market a generic version of Truvada. In the notice, Mylan alleges that two of the patents associated with emtricitabine and one of our patents associated with the fixed-dose combination of emtricitabine with tenofovir disoproxil fumarate are invalid, unenforceable and/or will not be infringed by Mylan's manufacture, use or sale of a generic version of Truvada. In June 2014, we filed a lawsuit against Mylan in U.S. District Court for the Northern District of West Virginia for infringement of our patents. In June 2014, we received notice that Mylan submitted petitions for Inter Partes Review (IPR) to the PTAB alleging that four patents associated with tenofovir disoproxil fumarate are invalid. We opposed Mylan’s petitions. In December 2014, the PTAB issued decisions denying each of Mylan’s petitions for IPR against the tenofovir disoproxil fumarate-associated patents on the grounds that Mylan had not established a reasonable likelihood of success that it would prevail in its challenge to each of these patents. In January 2015, Mylan requested a rehearing on the basis that it believes the PTAB decision is wrong. In August 2015, the PTAB denied Mylan's request for a rehearing on the three patents covering the tenofovir disoproxil prodrug. In August 2015, we received notice that Mylan submitted an ANDA to the FDA requesting permission to manufacture and market a generic version of Complera. In the notice, Mylan alleges that our patents associated with emtricitabine, rilpivirine and the fixed-dose combination are invalid, unenforceable and/or will not be infringed by Mylan's manufacture, use or sale of a generic version of Complera. We are currently evaluating Mylan's notice. Apotex In June 2014, we received notice that Apotex Corp. (Apotex) submitted an abbreviated new drug submission (ANDS) to Health Canada requesting permission to manufacture and market a generic fixed-dose combination of emtricitabine and tenofovir disoproxil fumarate and a separate ANDS requesting permission to manufacture and market a generic version of Viread. In the notice, Apotex alleges that three of the patents associated with Truvada and two of the patents associated with Viread are invalid, unenforceable and/or will not be infringed by Apotex's manufacture, use or sale of a generic version of Truvada or Viread. In August 2014, we filed a lawsuit against Apotex in the Federal Court of Canada seeking an order of prohibition against approval of this ANDS. Teva In August 2012, Teva Pharmaceuticals (Teva) filed an Impeachment Action in the Federal Court of Canada seeking invalidation of our two Canadian patents associated with Viread. In September 2013, a hearing on the consolidated requests for orders of prohibition in connection with all three of Teva’s ANDS filings to Health Canada (for Teva’s generic versions of Viread, Truvada, and Atripla) took place. In December 2013, the court issued our requested order prohibiting the Canadian Minister of Health from issuing a Notice of Compliance for Teva’s generic versions of our Viread, Truvada, and Atripla products until expiry of our patent in July 2017. Teva appealed the decision of the court prohibiting Health Canada from issuing the Notices of Compliance until expiry of our patent in July 2017. This decision did not rule on the validity of the patents and accordingly the only issue on appeal is whether Health Canada should be prohibited from issuing the Notices of Compliance for Teva’s products. The appeal will be heard by the Canadian Federal Court of Appeal after the trial in the Impeachment Action. Separately, the court will determine the validity of the patents in the pending Impeachment Action. A trial in the Impeachment Action is scheduled for November 2016. If Teva is successful in invalidating our patents, Teva may be able to launch generic versions of our Viread, Truvada and Atripla products in Canada prior to the expiry of our patents. Watson In February 2015, we received notice that Watson Laboratories, Inc. (Watson) submitted an ANDA to the FDA requesting permission to manufacture and market a generic version of Letairis. In the notice, Watson alleges that one of the patents associated with ambrisentan tablets is invalid, unenforceable and/or will not be infringed by Watson's manufacture, use or sale of a generic version of Letairis. In April 2015, we filed a lawsuit against Watson in the U.S. District Court for the District of New Jersey. SigmaPharm In June 2015, we received notice that SigmaPharm Laboratories, LLC (SigmaPharm) submitted an ANDA to the FDA requesting permission to manufacture and market a generic version of Letairis. In the notice, SigmaPharm alleges that one of the patents associated with ambrisentan tablets is invalid, unenforceable and/or will not be infringed by SigmaPharm’s manufacture, use or sale of a generic version of Letairis. In June 2015, we filed a lawsuit against SigmaPharm in the U.S. District Court for the District of New Jersey and we also filed a protective suit with the U.S. District Court for the District of Pennsylvania. Department of Justice Investigation In June 2011, we received a subpoena from the U.S. Attorney's Office for the Northern District of California requesting documents related to the manufacture, and related quality and distribution practices, of Complera, Atripla, Truvada, Viread, Emtriva, Hepsera and Letairis. We cooperated with the government’s inquiry. In April 2014, the U.S. Department of Justice informed us that, following an investigation, it declined to intervene in a False Claims Act lawsuit filed by two former employees. In April 2014, the former employees served a First Amended Complaint. In January 2015, the federal district court issued an order granting in its entirety, without prejudice, our motion to dismiss the First Amended Complaint. In February 2015, the plaintiffs filed a Second Amended Complaint. We moved to dismiss the Second Amended Complaint and in June 2015, the federal district court issued an order granting our motion to dismiss the Second Amended Complaint. In July 2015, the plaintiffs filed a notice of appeal in the U.S. Court of Appeals for Ninth Circuit. Other Matters We are a party to various legal actions that arise 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.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY The following table summarizes the changes in stockholders' equity (in millions): Gilead Stockholders' Equity Noncontrolling Interest Total Stockholders' Equity Common Stock Additional Paid-In Capital Accumulated Other Comprehensive Income (Loss) Retained Earnings Shares Amount Balance at December 31, 2014 1,499 $ 2 $ 2,391 $ 301 $ 12,732 $ 393 $ 15,819 Net income — — — — 8,825 4 8,829 Other comprehensive loss, net of tax — — — (54 ) — — (54 ) Change in noncontrolling interest — — — — — (50 ) (50 ) Issuances under employee stock purchase plan 1 — 52 — — — 52 Issuances under equity incentive plans 14 — 151 — — — 151 Stock-based compensation — — 188 — — — 188 Tax benefits from employee stock plans — — 326 — — — 326 Repurchases of common stock (41 ) — (85 ) — (4,046 ) — (4,131 ) Convertible notes settlement — — (508 ) — — — (508 ) Convertible notes hedge settlement — — 508 — — — 508 Dividends — — — — (639 ) — (639 ) Warrants settlement — — (3,031 ) — (834 ) — (3,865 ) Reclassification to equity component of currently redeemable convertible notes — — 8 — — — 8 Balance at June 30, 2015 1,473 $ 2 $ — $ 247 $ 16,038 $ 347 $ 16,634 Accumulated Other Comprehensive Income (Loss) The following table summarizes the changes in accumulated OCI by component, net of tax (in millions): Foreign Currency Items Unrealized Gains and Losses on Available-for-Sale Securities Unrealized Gains and Losses on Cash Flow Hedges Total Balance at December 31, 2014 $ (54 ) $ 12 $ 343 $ 301 Other comprehensive income (loss) before reclassifications (7 ) 3 273 269 Amounts reclassified from accumulated other comprehensive income (loss) — — (323 ) (323 ) Net current period other comprehensive income (loss) (7 ) 3 (50 ) (54 ) Balance at June 30, 2015 $ (61 ) $ 15 $ 293 $ 247 Amounts reclassified for gains (losses) on cash flow hedges are recorded as part of product sales on our Condensed Consolidated Statements of Income. Amounts reclassified for gains (losses) on available-for-sale securities are recorded as part of other income (expense), net on our Condensed Consolidated Statements of Income. Repurchases of Common Stock We completed our $5.0 billion stock repurchase program authorized in May 2014 and repurchased a total of $3.0 billion or 30 million shares of common stock under the program in the first quarter of 2015. During the second quarter of 2015, we began repurchases under our $15.0 billion stock repurchase program authorized in January 2015 (2015 Program) and repurchased a total of $900 million or 9 million shares of common stock. Dividends During the second quarter of 2015, we declared a quarterly cash dividend of $0.43 per share, or a total of $639 million to all stockholders of record as of the close of business on June 16, 2015. This is the first quarterly dividend declared under our dividend program previously announced in February 2015. On July 28, 2015, we announced that our Board of Directors declared a quarterly cash dividend of $0.43 per share of our common stock, with a payment date of September 29, 2015 to all stockholders of record as of the close of business on September 16, 2015. Additional Paid-In Capital During the quarter our additional paid-in capital balance became zero, primarily due to the settlement of a portion of our 2016 Warrants (see Note 8, Debt and Credit Facility). As additional paid-in capital was reduced to zero, the remainder of the warrants settlement was recorded as a reduction in retained earnings.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2015
Share-based Compensation [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION The following table summarizes the stock-based compensation expenses included in our Condensed Consolidated Statements of Income (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Cost of goods sold $ 3 $ 2 $ 6 $ 5 Research and development expenses 42 37 84 71 Selling, general and administrative expenses 51 44 98 89 Stock-based compensation expenses included in total costs and expenses 96 83 188 165 Income tax effect (25 ) (11 ) (48 ) (30 ) Stock-based compensation expenses, net of tax $ 71 $ 72 $ 140 $ 135

Net Income Per Share Attributab

Net Income Per Share Attributable to Gilead Common Stockholders	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Net Income Per Share Attributable to Gilead Common Stockholders	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 outstanding and other dilutive securities outstanding during the period. The potential dilutive shares of our common stock resulting from the assumed exercise of outstanding stock options, performance shares and the assumed exercise of warrants relating to our convertible senior notes, including the convertible senior notes that were due in May 2014 (the May 2014 Notes) and the May 2016 Notes (collectively, the May Notes) are determined under the treasury stock method. Because the principal amount of the May Notes has been or will be settled in cash, only the conversion spread relating to the May Notes is included in our calculation of diluted net income per share attributable to Gilead common stockholders. Our May 2014 Notes matured and as a result, we have only included their impact for the periods they were outstanding on our net income per share calculations for the periods shown. Our common stock resulting from the assumed settlement of the conversion spread of the May 2014 Notes had a dilutive effect when the average market price of our common stock during the period exceeded the conversion price of $22.54 for the May 2014 Notes. Our common stock resulting from the assumed settlement of the conversion spread of the May 2016 Notes has a dilutive effect when the average market price of our common stock during the period exceeds the conversion price for the May 2016 Notes. See Note 8, Debt and Credit Facility for additional information. Warrants related to our May 2014 Notes and a portion of the 2016 Warrants were settled and as a result, we have only included their impact for the periods they were outstanding on our net income per share calculations. Warrants relating to the May 2014 Notes had a dilutive effect when the average market price of our common stock during the period exceeded the warrants’ exercise price of $28.38 . Warrants relating to the May 2016 Notes had a dilutive effect when the average market price of our common stock during the period exceeded the warrants’ exercise price. See Note 8, Debt and Credit Facility for additional information. We have excluded stock options to purchase approximately 1 million weighted-average shares of our common stock that were outstanding for both of the three and six months ended June 30, 2015 and 2014. These shares were excluded in the computation of diluted net income per share attributable to Gilead common stockholders because their effect was antidilutive. The following table is a reconciliation of the numerator and denominator used in the calculation of basic and diluted net income per share attributable to Gilead common stockholders (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Net income attributable to Gilead $ 4,492 $ 3,656 $ 8,825 $ 5,883 Shares used in per share calculation - basic 1,472 1,533 1,480 1,535 Effect of dilutive securities: Stock options and equivalents 23 31 25 33 Conversion spread related to the May Notes 14 31 15 35 Warrants related to the May Notes 31 69 35 69 Shares used in per share calculation - diluted 1,540 1,664 1,555 1,672

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We operate in one business segment, which primarily focuses on the discovery, development and commercialization of innovative medicines in areas of unmet medical need. All products are included in one segment, because the majority of our products have similar economic and other characteristics, including the nature of the products and production processes, type of customers, distribution methods and regulatory environment. Total product sales on an individual product basis are summarized in the following table (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Antiviral products: Harvoni $ 3,608 $ — $ 7,187 $ — Sovaldi 1,291 3,481 2,263 5,755 Truvada 849 806 1,620 1,566 Atripla 782 870 1,516 1,650 Stribild 447 270 803 485 Complera/Eviplera 367 299 687 550 Viread 271 261 505 472 Other antiviral 16 25 38 43 Total antiviral products 7,631 6,012 14,619 10,521 Other products: Letairis 176 145 327 268 Ranexa 141 123 258 234 AmBisome 103 94 188 186 Zydelig 30 — 56 — Other 45 39 83 75 Total product sales $ 8,126 $ 6,413 $ 15,531 $ 11,284 The following table summarizes revenues from each of our customers who individually accounted for 10% or more of our total revenues (as a percentage of total revenues): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 McKesson Corp. 24 % 25 % 25 % 24 % AmerisourceBergen Corp. 20 % 27 % 20 % 27 % Cardinal Health, Inc. 15 % 12 % 16 % 13 %

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	INCOME TAXES Our income tax rate of 18.4% and 17.9% for the three and six months ended June 30, 2015 , differed from the U.S. federal statutory rate of 35% due primarily to certain operating earnings from non-U.S. subsidiaries that are considered indefinitely reinvested and tax credits, partially offset by state taxes, our portion of the non-tax deductible Branded Prescription Drug Fee, also known as the pharmaceutical excise tax, and amortization expense of the intangible asset related to sofosbuvir for which we receive no tax benefit. We do not provide for U.S. income taxes on undistributed earnings of our foreign operations that are intended to be indefinitely reinvested in our foreign subsidiaries. We file federal, state and foreign income tax returns in many jurisdictions in the United States and abroad. For federal income tax purposes, the statute of limitations is open for 2010 and onwards. 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. For California income tax purposes, the statute of limitations is open for 2008 and onwards. Our income tax returns are audited by federal, state and foreign tax authorities. We are currently under examination by the Internal Revenue Service (IRS) for the 2010, 2011 and 2012 tax years and by various state and foreign jurisdictions. 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. We record liabilities related to uncertain tax positions in accordance with the income tax guidance which clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements by prescribing a minimum recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. Resolution of one or more of these uncertain tax positions in any period may have a material impact on the results of operations for that period.

Summary of Significant Accoun22

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information. The financial statements include all adjustments (consisting only of normal recurring adjustments) that the management of Gilead Sciences, Inc. (Gilead, we or us) believes are necessary for a fair presentation of the periods presented. These interim financial results are not necessarily indicative of results expected for the full fiscal year or for any subsequent interim period. The accompanying Condensed Consolidated Financial Statements include the accounts of Gilead, our wholly-owned subsidiaries and certain variable interest entities for which we are the primary beneficiary. For consolidated entities where we own or are exposed to less than 100% of the economics, we record net income (loss) attributable to noncontrolling interests in our Condensed Consolidated Statements of Income equal to the percentage of the economic or ownership interest retained in such entities by the respective noncontrolling parties. All intercompany transactions have been eliminated. The Condensed Consolidated Financial Statements include the results of companies acquired by us from the date of each acquisition for the applicable reporting periods. The accompanying Condensed Consolidated Financial Statements and related Notes to Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and the related notes thereto for the year ended December 31, 2014 , included in our Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission.
Significant Accounting Policies, Estimates and Judgments	Significant Accounting Policies, Estimates and Judgments The preparation of these Condensed Consolidated Financial Statements 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, management evaluates its 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. Actual results may differ significantly from these estimates. Estimates are assessed each period and updated to reflect current information.
Concentrations of Risk	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. The majority of our trade accounts receivable arises from product sales in the United States and Europe. As of June 30, 2015 , our accounts receivable in Southern Europe, specifically Greece, Italy, Portugal and Spain, totaled approximately $1.5 billion , of which $118 million were greater than 120 days past due and $29 million were greater than 365 days past due. To date, we have not experienced significant losses with respect to the collection of our accounts receivable. We believe that our allowance for doubtful accounts was adequate at June 30, 2015 .
Recent Accounting Pronouncement	Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (FASB) issued an accounting standard update which requires presentation of debt issuance costs as a direct deduction from the carrying amount of a recognized debt liability on the balance sheet. The update does not change current guidance on the recognition and measurement of debt issuance costs. This guidance will become effective for us for annual periods beginning after December 15, 2015, and interim periods thereafter. At the time of adoption, we will reclassify debt issuance costs to a liability as a direct deduction from the carrying value of the debt, consistent with the presentation of a debt discount. We do not expect that the adoption of this update will have a material impact on our Condensed Consolidated Financial Statements. In May 2014, the FASB, jointly with the International Accounting Standards Board, issued a comprehensive new standard on revenue recognition from contracts with customers. The standard's core principle is that a reporting entity will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. On July 9, 2015, the FASB decided to delay the effective date of the new standard by one year. The standard would become effective for us beginning in the first quarter of 2018. Early application would be permitted in 2017. Entities would have the option of using either a full retrospective or a modified retrospective approach to adopt this new guidance. We are currently evaluating the impact of our adoption of this standard on our Condensed Consolidated Financial Statements.

Fair value measurements (Tables

Fair value measurements (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Schedule of Fair Value Classified by Level of Input	The following table summarizes the assets and liabilities measured at fair value on a recurring basis, by level, within the fair value hierarchy (in millions): June 30, 2015 December 31, 2014 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Money market funds $ 5,594 $ — $ — $ 5,594 $ 7,926 $ — $ — $ 7,926 Corporate debt securities — 3,435 — 3,435 — 938 — 938 U.S. treasury securities 2,085 — — 2,085 363 — — 363 Residential mortgage and asset-backed securities — 914 — 914 — 269 — 269 Certificates of deposit — 361 — 361 — — — — Foreign currency derivative contracts — 342 — 342 — 349 — 349 U.S. government agencies securities — 293 — 293 — 113 — 113 Non-U.S. government securities — 169 — 169 — — — — Municipal debt securities — 43 — 43 — 16 — 16 Deferred compensation plan 63 — — 63 54 — — 54 $ 7,742 $ 5,557 $ — $ 13,299 $ 8,343 $ 1,685 $ — $ 10,028 Liabilities: Contingent consideration $ — $ — $ 140 $ 140 $ — $ — $ 133 $ 133 Deferred compensation plan 63 — — 63 54 — — 54 Foreign currency derivative contracts — 39 — 39 — — — — $ 63 $ 39 $ 140 $ 242 $ 54 $ — $ 133 $ 187
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments	The fair values of our convertible senior notes and senior unsecured notes were determined using Level 2 inputs based on their quoted market values. The following table summarizes the carrying values and fair values of our convertible senior notes and senior unsecured notes (in millions): June 30, 2015 December 31, 2014 Type of Borrowing Description Carrying Value Fair Value Carrying Value Fair Value Convertible Senior May 2016 Notes $ 352 $ 1,851 $ 483 $ 2,097 Senior Unsecured April 2021 Notes 995 1,094 995 1,108 Senior Unsecured December 2016 Notes 700 720 700 727 Senior Unsecured December 2021 Notes 1,248 1,366 1,248 1,377 Senior Unsecured December 2041 Notes 998 1,152 998 1,229 Senior Unsecured April 2019 Notes 499 501 499 500 Senior Unsecured April 2024 Notes 1,748 1,789 1,747 1,836 Senior Unsecured April 2044 Notes 1,747 1,809 1,747 1,954 Senior Unsecured February 2020 Notes 499 502 499 504 Senior Unsecured February 2025 Notes 1,748 1,759 1,748 1,797 Senior Unsecured February 2045 Notes 1,740 1,735 1,740 1,872

Available-for-sale securities (

Available-for-sale securities (Tables)	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Summary of Available-for-Sale Securities at Estimated Fair Value	The following table is a summary of available-for-sale securities recorded in cash and cash equivalents or marketable securities in our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 December 31, 2014 Amortized Gross Gross Estimated Amortized Gross Gross Estimated Money market funds $ 5,594 $ — $ — $ 5,594 $ 7,926 $ — $ — $ 7,926 Corporate debt securities 3,438 2 (5 ) 3,435 941 — (3 ) 938 U.S. treasury securities 2,083 2 — 2,085 363 — — 363 Residential mortgage and asset-backed securities 914 1 (1 ) 914 269 — — 269 Certificates of deposit 361 — — 361 — — — — U.S. government agencies securities 293 — — 293 113 — — 113 Non-U.S. government securities 169 — — 169 — — — — Municipal debt securities 43 — — 43 16 — — 16 Total $ 12,895 $ 5 $ (6 ) $ 12,894 $ 9,628 $ — $ (3 ) $ 9,625
Summary of the Classification of Available-for-Sale Securities	The following table summarizes the classification of the available-for-sale securities on our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 December 31, 2014 Cash and cash equivalents $ 5,644 $ 7,926 Short-term marketable securities 1,194 101 Long-term marketable securities 6,056 1,598 Total $ 12,894 $ 9,625
Summary of Available-for-Sale Securities by Contractual Maturity	The following table summarizes our portfolio of available-for-sale securities by contractual maturity (in millions): June 30, 2015 Amortized Cost Fair Value Less than one year $ 6,838 $ 6,838 Greater than one year but less than five years 5,999 5,998 Greater than five years but less than ten years 34 34 Greater than ten years 24 24 Total $ 12,895 $ 12,894
Summary of Available-for-Sale Securities in a Continuous Loss Position Deemed not to be Other-than-Temporarily Impaired	The following table summarizes our available-for-sale debt securities that were in a continuous unrealized loss position, but were not deemed to be other-than-temporarily impaired (in millions): Less Than 12 Months 12 Months or Greater Total Gross Estimated Gross Estimated Gross Estimated June 30, 2015 Corporate debt securities $ (5 ) $ 2,101 $ — $ 21 $ (5 ) $ 2,122 Residential mortgage and asset-backed securities (1 ) 499 — 16 (1 ) 515 U.S. treasury securities — 378 — — — 378 U.S. government agencies securities — 100 — — — 100 Non-U.S. government securities — 151 — — — 151 Municipal debt securities — 13 — — — 13 Total $ (6 ) $ 3,242 $ — $ 37 $ (6 ) $ 3,279 December 31, 2014 Corporate debt securities $ (3 ) $ 802 $ — $ — $ (3 ) $ 802 Residential mortgage and asset-backed securities — 227 — 1 — 228 U.S. treasury securities — 206 — — — 206 U.S. government agencies securities — 22 — — — 22 Municipal debt securities — 2 — — — 2 Total $ (3 ) $ 1,259 $ — $ 1 $ (3 ) $ 1,260

Derivative Financial Instrume25

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values of Derivative Instruments on Condensed Consolidated Balance Sheets	The following table summarizes the classification and fair values of derivative instruments on our Condensed Consolidated Balance Sheets (in millions): June 30, 2015 Asset Derivatives Liability Derivatives Classification Fair Value Classification Fair Value Derivatives designated as hedges: Foreign currency exchange contracts Other current assets $ 340 Other accrued liabilities $ (29 ) Foreign currency exchange contracts Other long-term assets 2 Other long-term obligations (10 ) Total derivatives $ 342 $ (39 ) December 31, 2014 Asset Derivatives Liability Derivatives Classification Fair Value Classification Fair Value Derivatives designated as hedges: Foreign currency exchange contracts Other current assets $ 314 Other accrued liabilities $ — Foreign currency exchange contracts Other long-term assets 35 Other long-term obligations — Total derivatives $ 349 $ —
Summary of the Effect of Foreign Currency Exchange Contracts on Condensed Consolidated Statements of Income	The following table summarizes the effect of our foreign currency exchange contracts on our Condensed Consolidated Financial Statements (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Derivatives designated as hedges: Gains (losses) recognized in accumulated OCI (effective portion) $ (113 ) $ 30 $ 276 $ 33 Gains (losses) reclassified from accumulated OCI into product sales (effective portion) $ 187 $ (19 ) $ 332 $ (40 ) Gains (losses) recognized in other income (expense), net (ineffective portion and amounts excluded from effectiveness testing) $ 6 $ (4 ) $ 7 $ (4 ) Derivatives not designated as hedges: Gains (losses) recognized in other income (expense), net $ (40 ) $ 8 $ 68 $ 9
Derivatives Netting Tabular Disclosure	The following table summarizes the potential effect of offsetting derivatives by type of financial instrument on our Condensed Consolidated Balance Sheets (in millions): As of June 30, 2015 Offsetting of Derivative Assets/Liabilities Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet Description Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheet Amounts of Assets/Liabilities Presented in the Condensed Consolidated Balance Sheet Derivative Financial Instruments Cash Collateral Received/Pledged Net Amount (Legal Offset) Derivative assets $ 342 $ — $ 342 $ (38 ) $ — $ 304 Derivative liabilities (39 ) — (39 ) 38 — (1 ) As of December 31, 2014 Offsetting of Derivative Assets/Liabilities Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet Description Gross Amounts of Recognized Assets/Liabilities Gross Amounts Offset in the Condensed Consolidated Balance Sheet Amounts of Assets/Liabilities Presented in the Condensed Consolidated Balance Sheet Derivative Financial Instruments Cash Collateral Received/Pledged Net Amount (Legal Offset) Derivative assets $ 349 $ — $ 349 $ — $ — $ 349 Derivative liabilities — — — — — —

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2015
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories are summarized as follows (in millions): June 30, 2015 December 31, 2014 Raw materials $ 1,206 $ 909 Work in process 706 500 Finished goods 592 466 Total $ 2,504 $ 1,875 Reported as: Inventories $ 2,039 $ 1,386 Other long-term assets 465 489 Total $ 2,504 $ 1,875

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The following table summarizes the carrying amounts of our intangible assets (in millions): June 30, 2015 December 31, 2014 Finite-lived intangible assets $ 10,228 $ 10,641 Indefinite-lived intangible assets 432 432 Total intangible assets $ 10,660 $ 11,073
Schedule of Finite-Lived Intangible Assets	The following table summarizes our finite-lived intangible assets (in millions): June 30, 2015 December 31, 2014 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible asset - sofosbuvir $ 10,720 $ 1,106 $ 10,720 $ 757 Intangible asset - Ranexa 688 320 688 277 Other 455 209 455 188 Total $ 11,863 $ 1,635 $ 11,863 $ 1,222
Estimated Future Amortization Expense	As of June 30, 2015 , the estimated future amortization expense associated with our finite-lived intangible assets for the remaining six months of 2015 and each of the five succeeding fiscal years is as follows (in millions): Fiscal Year Amount 2015 (remaining six months) $ 413 2016 832 2017 846 2018 853 2019 741 2020 713 Total $ 4,398
Schedule of Indefinite-Lived Intangible Assets	The following table summarizes our indefinite-lived intangible assets as of June 30, 2015 and December 31, 2014 (in millions): Amount Indefinite-lived intangible asset - momelotinib (formerly CYT387) $ 308 Indefinite-lived intangible assets - Other 117 425 Foreign currency translation adjustment 7 Total $ 432

Collaborative Arrangements Vari

Collaborative Arrangements Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2015
Collaborative Arrangements [Abstract]
Schedule of Variable Interest Entities	Selected financial information for the joint venture was as follows (in millions): June 30, 2015 December 31, 2014 Total assets $ 2,751 $ 2,138 Cash and cash equivalents 245 250 Accounts receivable, net 279 297 Inventories 2,225 1,590 Total liabilities 1,910 1,157 Accounts payable 1,501 749 Other accrued liabilities 408 408

Debt and Credit Facility (Table

Debt and Credit Facility (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Schedule of Debt Instruments	The following table summarizes the carrying amounts of our borrowings under various financing arrangements (in millions): Type of Borrowing Description Issue Date Due Date Interest Rate June 30, December 31, 2014 Convertible Senior May 2016 Notes July 2010 May 2016 1.625% $ 352 $ 483 Senior Unsecured April 2021 Notes March 2011 April 2021 4.50% 995 995 Senior Unsecured December 2016 Notes December 2011 December 2016 3.05% 700 700 Senior Unsecured December 2021 Notes December 2011 December 2021 4.40% 1,248 1,248 Senior Unsecured December 2041 Notes December 2011 December 2041 5.65% 998 998 Senior Unsecured April 2019 Notes March 2014 April 2019 2.05% 499 499 Senior Unsecured April 2024 Notes March 2014 April 2024 3.70% 1,748 1,747 Senior Unsecured April 2044 Notes March 2014 April 2044 4.80% 1,747 1,747 Senior Unsecured February 2020 Notes November 2014 February 2020 2.35% 499 499 Senior Unsecured February 2025 Notes November 2014 February 2025 3.50% 1,748 1,748 Senior Unsecured February 2045 Notes November 2014 February 2045 4.50% 1,740 1,740 Total debt, net 12,274 12,404 Less current portion 352 483 Total long-term debt, net $ 11,922 $ 11,921

Stockholders' Equity Schedule o

Stockholders' Equity Schedule of Stockholders Equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Schedule of Stockholders Equity	The following table summarizes the changes in stockholders' equity (in millions): Gilead Stockholders' Equity Noncontrolling Interest Total Stockholders' Equity Common Stock Additional Paid-In Capital Accumulated Other Comprehensive Income (Loss) Retained Earnings Shares Amount Balance at December 31, 2014 1,499 $ 2 $ 2,391 $ 301 $ 12,732 $ 393 $ 15,819 Net income — — — — 8,825 4 8,829 Other comprehensive loss, net of tax — — — (54 ) — — (54 ) Change in noncontrolling interest — — — — — (50 ) (50 ) Issuances under employee stock purchase plan 1 — 52 — — — 52 Issuances under equity incentive plans 14 — 151 — — — 151 Stock-based compensation — — 188 — — — 188 Tax benefits from employee stock plans — — 326 — — — 326 Repurchases of common stock (41 ) — (85 ) — (4,046 ) — (4,131 ) Convertible notes settlement — — (508 ) — — — (508 ) Convertible notes hedge settlement — — 508 — — — 508 Dividends — — — — (639 ) — (639 ) Warrants settlement — — (3,031 ) — (834 ) — (3,865 ) Reclassification to equity component of currently redeemable convertible notes — — 8 — — — 8 Balance at June 30, 2015 1,473 $ 2 $ — $ 247 $ 16,038 $ 347 $ 16,634
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in accumulated OCI by component, net of tax (in millions): Foreign Currency Items Unrealized Gains and Losses on Available-for-Sale Securities Unrealized Gains and Losses on Cash Flow Hedges Total Balance at December 31, 2014 $ (54 ) $ 12 $ 343 $ 301 Other comprehensive income (loss) before reclassifications (7 ) 3 273 269 Amounts reclassified from accumulated other comprehensive income (loss) — — (323 ) (323 ) Net current period other comprehensive income (loss) (7 ) 3 (50 ) (54 ) Balance at June 30, 2015 $ (61 ) $ 15 $ 293 $ 247

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2015
Share-based Compensation [Abstract]
Schedule of Stock-Based Compensation Expenses Included in Consolidated Statement of Income	The following table summarizes the stock-based compensation expenses included in our Condensed Consolidated Statements of Income (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Cost of goods sold $ 3 $ 2 $ 6 $ 5 Research and development expenses 42 37 84 71 Selling, general and administrative expenses 51 44 98 89 Stock-based compensation expenses included in total costs and expenses 96 83 188 165 Income tax effect (25 ) (11 ) (48 ) (30 ) Stock-based compensation expenses, net of tax $ 71 $ 72 $ 140 $ 135

Net Income Per Share Attribut32

Net Income Per Share Attributable to Gilead Common Stockholders (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Schedule of Numerator and Denominator Used in the Calculation of Basic and Diluted Earnings Per Share	The following table is a reconciliation of the numerator and denominator used in the calculation of basic and diluted net income per share attributable to Gilead common stockholders (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Net income attributable to Gilead $ 4,492 $ 3,656 $ 8,825 $ 5,883 Shares used in per share calculation - basic 1,472 1,533 1,480 1,535 Effect of dilutive securities: Stock options and equivalents 23 31 25 33 Conversion spread related to the May Notes 14 31 15 35 Warrants related to the May Notes 31 69 35 69 Shares used in per share calculation - diluted 1,540 1,664 1,555 1,672

Segment information (Tables)

Segment information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Product Sales by Product	Total product sales on an individual product basis are summarized in the following table (in millions): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 Antiviral products: Harvoni $ 3,608 $ — $ 7,187 $ — Sovaldi 1,291 3,481 2,263 5,755 Truvada 849 806 1,620 1,566 Atripla 782 870 1,516 1,650 Stribild 447 270 803 485 Complera/Eviplera 367 299 687 550 Viread 271 261 505 472 Other antiviral 16 25 38 43 Total antiviral products 7,631 6,012 14,619 10,521 Other products: Letairis 176 145 327 268 Ranexa 141 123 258 234 AmBisome 103 94 188 186 Zydelig 30 — 56 — Other 45 39 83 75 Total product sales $ 8,126 $ 6,413 $ 15,531 $ 11,284
Schedule of Revenue by Major Customers	The following table summarizes revenues from each of our customers who individually accounted for 10% or more of our total revenues (as a percentage of total revenues): Three Months Ended Six Months Ended June 30, June 30, 2015 2014 2015 2014 McKesson Corp. 24 % 25 % 25 % 24 % AmerisourceBergen Corp. 20 % 27 % 20 % 27 % Cardinal Health, Inc. 15 % 12 % 16 % 13 %

Summary of Significant Accoun34

Summary of Significant Accounting Policies (Details) - Southern Europe [Member] $ in Millions	Jun. 30, 2015USD ($)
Southern European Receivables [Line Items]
Accounts Receivable, Gross	$ 1,500
Greater than 120 Days
Southern European Receivables [Line Items]
Accounts Receivable, Gross	118
Greater Than 12 Months
Southern European Receivables [Line Items]
Accounts Receivable, Gross	$ 29

Fair value measurements (Summar

Fair value measurements (Summary of assets and liabilities recorded at fair value) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	$ 12,894	$ 9,625
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative contracts	0	0
Deferred compensation plan	63	54
Fair value, Assets, Total	7,742	8,343
Contingent consideration	0	0
Deferred compensation plan	63	54
Foreign currency derivative contracts	0	0
Fair value, Liabilities, Total	63	54
Fair Value, Measurements, Recurring | Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	5,594	7,926
Fair Value, Measurements, Recurring | Level 1 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	2,085	363
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. government agencies securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Municipal debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative contracts	342	349
Deferred compensation plan	0	0
Fair value, Assets, Total	5,557	1,685
Contingent consideration	0	0
Deferred compensation plan	0	0
Foreign currency derivative contracts	39	0
Fair value, Liabilities, Total	39	0
Fair Value, Measurements, Recurring | Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	3,435	938
Fair Value, Measurements, Recurring | Level 2 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	914	269
Fair Value, Measurements, Recurring | Level 2 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	361	0
Fair Value, Measurements, Recurring | Level 2 | U.S. government agencies securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	293	113
Fair Value, Measurements, Recurring | Level 2 | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	169	0
Fair Value, Measurements, Recurring | Level 2 | Municipal debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	43	16
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative contracts	0	0
Deferred compensation plan	0	0
Fair value, Assets, Total	0	0
Contingent consideration	140	133
Deferred compensation plan	0	0
Foreign currency derivative contracts	0	0
Fair value, Liabilities, Total	140	133
Fair Value, Measurements, Recurring | Level 3 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government agencies securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Municipal debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	0	0
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency derivative contracts	342	349
Deferred compensation plan	63	54
Fair value, Assets, Total	13,299	10,028
Contingent consideration	140	133
Deferred compensation plan	63	54
Foreign currency derivative contracts	39	0
Fair value, Liabilities, Total	242	187
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	5,594	7,926
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	3,435	938
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | U.S. treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	2,085	363
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Residential mortgage and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	914	269
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	361	0
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | U.S. government agencies securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	293	113
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	169	0
Fair Value, Measurements, Recurring | Estimate of Fair Value Measurement [Member] | Municipal debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated Fair Value	$ 43	$ 16

Fair Value and Carrying Value o

Fair Value and Carrying Value of Debt (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Convertible Senior Notes Due In May 2016
Fair Value and Carrying Value of Debt [Line Items]
Debt Instrument, Fair Value Disclosure	$ 1,851	$ 2,097
Senior Unsecured Notes Due In April 2021
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	995	995
Debt Instrument, Fair Value Disclosure	1,094	1,108
Senior Unsecured Notes Due In December 2016
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	700	700
Debt Instrument, Fair Value Disclosure	720	727
Senior Unsecured Notes Due In December 2021
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	1,248	1,248
Debt Instrument, Fair Value Disclosure	1,366	1,377
Senior Unsecured Notes Due In December 2041
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	998	998
Debt Instrument, Fair Value Disclosure	1,152	1,229
Senior Unsecured Notes Due in April 2019
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	499	499
Debt Instrument, Fair Value Disclosure	501	500
Senior Unsecured Notes Due in April 2024
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	1,748	1,747
Debt Instrument, Fair Value Disclosure	1,789	1,836
Senior Unsecured Notes Due in April 2044
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	1,747	1,747
Debt Instrument, Fair Value Disclosure	1,809	1,954
Senior Unsecured Notes Due In February 2020
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	499	499
Debt Instrument, Fair Value Disclosure	502	504
Senior Unsecured Notes Due in February 2025
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	1,748	1,748
Debt Instrument, Fair Value Disclosure	1,759	1,797
Senior Unsecured Notes Due in February 2045
Fair Value and Carrying Value of Debt [Line Items]
Senior Unsecured Notes, Carrying Value	1,740	1,740
Debt Instrument, Fair Value Disclosure	1,735	1,872
Convertible Senior Notes Due In May 2016
Fair Value and Carrying Value of Debt [Line Items]
Convertible Senior Notes, Carrying Value	$ 352	$ 483

Available-for-Sale Securities S

Available-for-Sale Securities Summary of Available-for-Sale Securities at Estimated Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	$ 12,895	$ 9,628
Gross Unrealized Gains	5	0
Gross Unrealized Losses	(6)	(3)
Estimated Fair Value	12,894	9,625
Money market funds
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	5,594	7,926
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	5,594	7,926
Corporate debt securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	3,438	941
Gross Unrealized Gains	2	0
Gross Unrealized Losses	(5)	(3)
Estimated Fair Value	3,435	938
U.S. treasury securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	2,083	363
Gross Unrealized Gains	2	0
Gross Unrealized Losses	0	0
Estimated Fair Value	2,085	363
Residential mortgage and asset-backed securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	914	269
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(1)	0
Estimated Fair Value	914	269
Certificates of deposit
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	361	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	361	0
U.S. government agencies securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	293	113
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	293	113
Non-U.S. government securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	169	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	169	0
Municipal debt securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	43	16
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 43	$ 16

Available-for-Sale Securities38

Available-for-Sale Securities Summary of the Classification of Available-for-Sale Securities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Cash and cash equivalents	$ 5,644	$ 7,926
Short-term marketable securities	1,194	101
Long-term marketable securities	6,056	1,598
Total	$ 12,894	$ 9,625

Available-for-Sale Securities39

Available-for-Sale Securities Summary of Available-for-Sale Securities by Contractual Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Amortized Cost
Less than one year	$ 6,838
Greater than one year but less than five years	5,999
Greater than five years but less than ten years	34
Greater than ten years	24
Amortized Cost	12,895	$ 9,628
Fair Value
Less than one year	6,838
Greater than one year but less than five years	5,998
Greater than five years but less than ten years	34
Greater than ten years	24
Total	$ 12,894	$ 9,625

Summary of Available-for-Sale S

Summary of Available-for-Sale Securities in a Continuous Unrealized Loss Position Deemed not to be Other-than-Temporarily Impaired (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (6)	$ (3)
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	3,242	1,259
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	37	1
Available for Sale Securities - Gross Unrealized Losses	(6)	(3)
Continuous Unrealized Loss Position, Estimated Fair Value	3,279	1,260
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(5)	(3)
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	2,101	802
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	21	0
Available for Sale Securities - Gross Unrealized Losses	(5)	(3)
Continuous Unrealized Loss Position, Estimated Fair Value	2,122	802
Residential mortgage and asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)	0
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	499	227
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	16	1
Available for Sale Securities - Gross Unrealized Losses	(1)	0
Continuous Unrealized Loss Position, Estimated Fair Value	515	228
U.S. treasury securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	378	206
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	0	0
Available for Sale Securities - Gross Unrealized Losses	0	0
Continuous Unrealized Loss Position, Estimated Fair Value	378	206
U.S. government agencies securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	100	22
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	0	0
Available for Sale Securities - Gross Unrealized Losses	0	0
Continuous Unrealized Loss Position, Estimated Fair Value	100	22
Non-U.S. government securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	151
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	0
Available for Sale Securities - Gross Unrealized Losses	0
Continuous Unrealized Loss Position, Estimated Fair Value	151
Municipal debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	0
Continuous Unrealized Loss Position, Less than 12 Months, Estimated Fair Value	13	2
Available-for-sale Securities, Gross Unrealized Loss, 12 months or Greater	0	0
Continuous Unrealized Loss Position, 12 Months or Greater, Estimated Fair Value	0	0
Available for Sale Securities - Gross Unrealized Losses	0	0
Continuous Unrealized Loss Position, Estimated Fair Value	$ 13	$ 2

Available-for-Sale Securities N

Available-for-Sale Securities Narrative (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)position	Dec. 31, 2014USD ($)position
Investments, Debt and Equity Securities [Abstract]
Cash excluded from available-for-sale debt securities table	$ 1,800	$ 2,100
Securities in unrealized loss positions, number of positions (securities) | position	1,034	468
Other than temporary impairment losses, investments	$ 0	$ 0

Derivative Financial Instrume42

Derivative Financial Instruments Summary of Information about the Fair Values of Derivative Instruments on Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Derivative Asset Fair Value	$ 342	$ 349
Derivative Liability, Fair Value	(39)	0
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Asset Fair Value	342
Derivative Liability, Fair Value	(39)
Foreign Exchange Contract | Designated as Hedging Instrument | Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset Fair Value	340	314
Foreign Exchange Contract | Designated as Hedging Instrument | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	(29)	0
Foreign Exchange Contract | Designated as Hedging Instrument | Other Long-Term Assets
Derivatives, Fair Value [Line Items]
Derivative Asset Fair Value	2	35
Foreign Exchange Contract | Designated as Hedging Instrument | Other Long-Term Obligations
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value	$ (10)	$ 0

Derivative Financial Instrume43

Derivative Financial Instruments Summary of the effect of foreign currency exchange contracts on condensed consolidated statements of income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gains (losses) recognized in accumulated OCI (effective portion)	$ (113)	$ 30	$ 276	$ 33
Gains (losses) reclassified from accumulated OCI into product sales (effective portion)	187	(19)	332	(40)
Gains (losses) recognized in other income (expense), net (ineffective portion and amounts excluded from effectiveness testing)	6	(4)	7	(4)
Gains (losses) recognized in other income (expense), net	$ (40)	$ 8	$ 68	$ 9

Derivative Financial Instrume44

Derivative Financial Instruments Table of Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	$ 342	$ 349
Gross Amounts Offset in the Condensed Consolidated Balance Sheet	0	0
Amount of Assets Presented in the Condensed Consolidated Balance Sheet	342	349
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet - Derivative Financial Instruments	(38)	0
Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet - Cash Collateral Received/Pledged	0	0
Net Amount (Legal Offset)	304	349
Derivative Liability [Abstract]
Gross Amount of Recognized Liabilities	(39)	0
Gross Amounts Offset in the Condensed Consolidated Balance Sheet	0	0
Amounts of Liabilities Presented in the Condensed Consolidated Balance Sheet	39	0
Gross Amount Not Offset in the Condensed Consolidated Balance Sheet - Derivative Financial Instruments	38	0
Gross Amount Not Offset in the Condensed Consolidated Balance Sheet - Cash Collateral Received/Pledged	0	0
Net Amount (Legal Offset)	$ (1)	$ 0

Derivative Financial Instrume45

Derivative Financial Instruments Derivative financial instruments Narrative (Details) - USD ($) $ in Billions	Jun. 30, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative, Notional Amount	$ 6.8	$ 6.4

Inventories Schedule of invento

Inventories Schedule of inventories (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 1,206	$ 909
Work in process	706	500
Finished goods	592	466
Total	2,504	1,875
Inventories	2,039	1,386
Other long-term assets	$ 465	$ 489

Inventories (Narrative) (Detail

Inventories (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Inventory [Line Items]
Inventories	$ 2,039	$ 1,386
Efavirenz | BMS & Gilead Sciences, LLC Joint Venture
Inventory [Line Items]
Inventories	$ 1,400	$ 806

Intangible Assets Schedule of C

Intangible Assets Schedule of Carrying Amount of Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived intangible assets	$ 10,228	$ 10,641
Indefinite-lived intangible assets	432	432
Total intangible assets	$ 10,660	$ 11,073

Intangible Assets Schedule of F

Intangible Assets Schedule of Finite Lived Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 11,863	$ 11,863
Accumulated Amortization	1,635	1,222
Intangible asset - sofosbuvir
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,720	10,720
Accumulated Amortization	1,106	757
Intangible asset - Ranexa
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	688	688
Accumulated Amortization	320	277
Other
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	455	455
Accumulated Amortization	$ 209	$ 188

Intangible Assets Schedule of50

Intangible Assets Schedule of Future Amortization Expense (Details) $ in Millions	Jun. 30, 2015USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2015 (remaining six months)	$ 413
2,016	832
2,017	846
2,018	853
2,019	741
2,020	713
Total	$ 4,398

Intangible Assets Schedule of I

Intangible Assets Schedule of Indefinite Lived Intangible Assets (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets	$ 432	$ 432
Indefinite-Lived Intangible Assets (Excluding Goodwill), Gross	425	425
Indefinite-lived Intangible Assets, Translation Adjustments	7	7
Indefinite-lived intangible asset - momelotinib (formerly CYT387)
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets	308	308
Other
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived Intangible Assets	$ 117	$ 117

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Cost of Sales
Acquired Indefinite-lived Intangible Assets [Line Items]
Amortization of Finite-Lived Intangible Assets	$ 207	$ 200	$ 413	$ 399

Collaborative Arrangements Narr

Collaborative Arrangements Narrative (Details) - BMS & Gilead Sciences, LLC Joint Venture - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Total assets
Variable Interest Entity [Line Items]
Variable interest entity, assets	$ 2,751	$ 2,138
Cash and cash equivalents
Variable Interest Entity [Line Items]
Variable interest entity, assets	245	250
Accounts receivable, net
Variable Interest Entity [Line Items]
Variable interest entity, assets	279	297
Inventories
Variable Interest Entity [Line Items]
Variable interest entity, assets	2,225	1,590
Total liabilities
Variable Interest Entity [Line Items]
Variable interest entity, liabilities	1,910	1,157
Accounts payable
Variable Interest Entity [Line Items]
Variable interest entity, liabilities	1,501	749
Other accrued liabilities
Variable Interest Entity [Line Items]
Variable interest entity, liabilities	$ 408	$ 408

Debt and Credit Facility Schedu

Debt and Credit Facility Schedule of Carrying Amounts of Senior Notes (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 12,274	$ 12,404
Less Current Portion	352	483
Total Long-Term Debt, Net	$ 11,922	11,921
Senior Unsecured Notes Due In April 2021
Debt Instrument [Line Items]
Stated interest rate	4.50%
Senior Unsecured Notes	$ 995	995
Senior Unsecured Notes Due In December 2016
Debt Instrument [Line Items]
Stated interest rate	3.05%
Senior Unsecured Notes	$ 700	700
Senior Unsecured Notes Due In December 2021
Debt Instrument [Line Items]
Stated interest rate	4.40%
Senior Unsecured Notes	$ 1,248	1,248
Senior Unsecured Notes Due In December 2041
Debt Instrument [Line Items]
Stated interest rate	5.65%
Senior Unsecured Notes	$ 998	998
Senior Unsecured Notes Due in April 2019
Debt Instrument [Line Items]
Stated interest rate	2.05%
Senior Unsecured Notes	$ 499	499
Senior Unsecured Notes Due in April 2024
Debt Instrument [Line Items]
Stated interest rate	3.70%
Senior Unsecured Notes	$ 1,748	1,747
Senior Unsecured Notes Due in April 2044
Debt Instrument [Line Items]
Stated interest rate	4.80%
Senior Unsecured Notes	$ 1,747	1,747
Senior Unsecured Notes Due In February 2020
Debt Instrument [Line Items]
Stated interest rate	2.35%
Senior Unsecured Notes	$ 499	499
Senior Unsecured Notes Due in February 2025
Debt Instrument [Line Items]
Stated interest rate	3.50%
Senior Unsecured Notes	$ 1,748	1,748
Senior Unsecured Notes Due in February 2045
Debt Instrument [Line Items]
Stated interest rate	4.50%
Senior Unsecured Notes	$ 1,740	1,740
Convertible Senior Notes Due In May 2016
Debt Instrument [Line Items]
Stated interest rate	1.625%
Convertible Senior Notes	$ 352	$ 483

Debt and Credit Facility Debt a

Debt and Credit Facility Debt and Credity Facility (Narrative) (Details) $ / shares in Units, shares in Millions	Jun. 30, 2015USD ($)$ / sharesshares	Jul. 31, 2010	Jun. 30, 2015USD ($)$ / sharesshares	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)$ / sharesshares
Debt Instrument [Line Items]
Proceeds from convertible note hedges			$ 508,000,000	$ 1,312,000,000
Equity component of currently redeemable convertible notes	$ 7,000,000		7,000,000		$ 15,000,000
Payments to settle warrants			3,865,000,000	$ 0
Convertible Senior Notes Due May 2016
Debt Instrument [Line Items]
Debt principal repayment, conversion			140,000,000
Debt Instrument, Convertible, Beneficial Conversion Feature			508,000,000
Proceeds from convertible note hedges			$ 508,000,000
Debt Instrument, Convertible, Conversion Ratio	44.2023	44.0428
Conversion of Notes Base Conversion Value					$ 1,000
Exercise price of warrants or rights (usd per share) | $ / shares	$ 22.62		$ 22.62		$ 22.71
2016 Warrants
Debt Instrument [Line Items]
Exercise price of warrants or rights (usd per share) | $ / shares	$ 29.62		$ 29.62		$ 30.05
Common stock underlying warrants | shares	46		46
Class of Warrant or Right, Outstanding | shares	9		9		55
Credit Facility Due January 2017
Debt Instrument [Line Items]
Long-term line of credit	$ 0		$ 0

Stockholders' Equity Schedule56

Stockholders' Equity Schedule of Stockholders Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			$ 15,819
Beginning Balance (in shares)			1,499
Net income	$ 4,497	$ 3,650	$ 8,829	$ 5,873
Other comprehensive loss, net of tax	(292)	$ 54	(54)	$ 83
Change in noncontrolling interest			(50)
Issuances under employee stock purchase plan			52
Issuances under equity incentive plans			151
Stock-based compensation			188
Tax benefits from employee stock plans			326
Repurchases of common stock			(4,131)
Convertible notes settlement			(508)
Convertible notes hedge settlement			508
Dividends	(639)		(639)
Warrants settlement			(3,865)
Reclassification to equity component of currently redeemable convertible notes			8
Balance at June 30, 2015	$ 16,634		$ 16,634
Ending Balance (in shares)	1,473		1,473
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			$ 2
Beginning Balance (in shares)			1,499
Issuances under employee stock purchase plan (in shares)			1
Issuances under equity incentive plans (in shares)			14
Repurchases of common stock (in shares)			(41)
Balance at June 30, 2015	$ 2		$ 2
Ending Balance (in shares)	1,473		1,473
Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			$ 2,391
Issuances under employee stock purchase plan			52
Issuances under equity incentive plans			151
Stock-based compensation			188
Tax benefits from employee stock plans			326
Repurchases of common stock			(85)
Convertible notes settlement			(508)
Convertible notes hedge settlement			508
Warrants settlement			(3,031)
Reclassification to equity component of currently redeemable convertible notes			8
Balance at June 30, 2015	$ 0		0
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			301
Other comprehensive loss, net of tax			(54)
Balance at June 30, 2015	247		247
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			12,732
Net income			8,825
Repurchases of common stock			(4,046)
Dividends			(639)
Warrants settlement			(834)
Balance at June 30, 2015	16,038		16,038
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			393
Net income			4
Change in noncontrolling interest			(50)
Balance at June 30, 2015	$ 347		$ 347

Stockholders' Equity Schedule57

Stockholders' Equity Schedule of Accumulated Comprehensive Income (loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			$ 301
Other comprehensive income (loss) before reclassifications			269
Amounts reclassified from accumulated other comprehensive income (loss)			(323)
Net current period other comprehensive income (loss)	$ (292)	$ 54	(54)	$ 83
Balance at March 31, 2015	247		247
Foreign Currency Items
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			(54)
Other comprehensive income (loss) before reclassifications			(7)
Amounts reclassified from accumulated other comprehensive income (loss)			0
Net current period other comprehensive income (loss)			(7)
Balance at March 31, 2015	(61)		(61)
Unrealized Gains and Losses on Available-for-Sale Securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			12
Other comprehensive income (loss) before reclassifications			3
Amounts reclassified from accumulated other comprehensive income (loss)			0
Net current period other comprehensive income (loss)			3
Balance at March 31, 2015	15		15
Unrealized Gains and Losses on Cash Flow Hedges
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at December 31, 2014			343
Other comprehensive income (loss) before reclassifications			273
Amounts reclassified from accumulated other comprehensive income (loss)			(323)
Net current period other comprehensive income (loss)			(50)
Balance at March 31, 2015	$ 293		$ 293

Stockholders' Equity Narrative

Stockholders' Equity Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Jul. 28, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Value					$ 4,131
Cash dividends declared per share		$ 0.43		$ 0	$ 0.43	$ 0
Dividends		$ 639			$ 639
2014 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchased and retired during period (shares)		9	30
Authorized amount		$ 5,000			5,000
2015 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock Repurchased During Period, Value		900	$ 3,000
Authorized amount		$ 15,000			$ 15,000
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Cash dividends declared per share	$ 0.43

Stock-Based Compensation Summar

Stock-Based Compensation Summary of Stock-Based Compensation (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses included in total costs and expenses	$ 96	$ 83	$ 188	$ 165
Income tax effect	(25)	(11)	(48)	(30)
Stock-based compensation expenses, net of tax	71	72	140	135
Cost of goods sold
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses included in total costs and expenses	3	2	6	5
Research and development expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses included in total costs and expenses	42	37	84	71
Selling, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expenses included in total costs and expenses	$ 51	$ 44	$ 98	$ 89

Net Income Per Share Attribut60

Net Income Per Share Attributable to Gilead Common Stockholders Reconciliation of the Numerator and Denominator Used in the Calculation of Basic and Diluted EPS (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Debt Instrument [Line Items]
Net income attributable to Gilead	$ 4,492	$ 3,656	$ 8,825	$ 5,883
Shares used in per share calculation - basic (in shares)	1,472	1,533	1,480	1,535
Stock options and equivalents (shares)	23	31	25	33
Conversion spread related to notes (shares)	14	31	15	35
Warrants related to the May Notes (shares)	31	69	35	69
Shares used in per share calculation - diluted (in shares)	1,540	1,664	1,555	1,672

Net Income Per Share Attribut61

Net Income Per Share Attributable to Gilead Common Stockholders (Narrative) (Details) - $ / shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Debt Instrument, Redemption [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1	1	1	1
Convertible Senior Notes Due In May 2014
Debt Instrument, Redemption [Line Items]
Debt Instrument, Convertible, Conversion Price	$ 22.54		$ 22.54
Exercise price of warrants or rights (usd per share)	$ 28.38		$ 28.38

Segment Information Segment rep

Segment Information Segment reporting information, revenue for reportable segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue from External Customer [Line Items]
Product sales	$ 8,126	$ 6,413	$ 15,531	$ 11,284
Total antiviral products
Revenue from External Customer [Line Items]
Product sales	7,631	6,012	14,619	10,521
Harvoni
Revenue from External Customer [Line Items]
Product sales	3,608	0	7,187	0
Sovaldi
Revenue from External Customer [Line Items]
Product sales	1,291	3,481	2,263	5,755
Truvada
Revenue from External Customer [Line Items]
Product sales	849	806	1,620	1,566
Atripla
Revenue from External Customer [Line Items]
Product sales	782	870	1,516	1,650
Stribild
Revenue from External Customer [Line Items]
Product sales	447	270	803	485
Complera/Eviplera
Revenue from External Customer [Line Items]
Product sales	367	299	687	550
Viread
Revenue from External Customer [Line Items]
Product sales	271	261	505	472
Other antiviral
Revenue from External Customer [Line Items]
Product sales	16	25	38	43
Letairis
Revenue from External Customer [Line Items]
Product sales	176	145	327	268
Ranexa
Revenue from External Customer [Line Items]
Product sales	141	123	258	234
AmBisome
Revenue from External Customer [Line Items]
Product sales	103	94	188	186
Zydelig
Revenue from External Customer [Line Items]
Product sales	30	0	56	0
Other
Revenue from External Customer [Line Items]
Product sales	$ 45	$ 39	$ 83	$ 75

Segment Information Schedule of

Segment Information Schedule of revenue by major customers (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
McKesson Corp.
Revenue, Major Customer [Line Items]
Percentage of Revenues	24.00%	25.00%	25.00%	24.00%
AmerisourceBergen Corp.
Revenue, Major Customer [Line Items]
Percentage of Revenues	20.00%	27.00%	20.00%	27.00%
Cardinal Health, Inc.
Revenue, Major Customer [Line Items]
Percentage of Revenues	15.00%	12.00%	16.00%	13.00%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - Jun. 30, 2015	Total	Total
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Effective income tax rate from continuing operations	18.40%	17.90%
Federal statutory income tax rate		35.00%