Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 4,332us-gaap_ProfitLoss	$ 2,223us-gaap_ProfitLoss
Other comprehensive income:
Net foreign currency translation gain (loss), net of tax	(10)	6
Available-for-sale securities:
Net unrealized gains, net of tax impact of $3 and $0	6	0
Net change	6	0
Cash flow hedges:
Net unrealized gains, net of tax impact of $6 and $2	383	1
Reclassifications to net income, net of tax impact of $(4) and $(1)	(141)	22
Net change	242	23
Other comprehensive income	238	29
Comprehensive income	4,570	2,252
Comprehensive loss attributable to noncontrolling interest	1	4
Comprehensive income attributable to Gilead	$ 4,571us-gaap_ComprehensiveIncomeNetOfTax	$ 2,256us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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

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