Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues [Abstract]
Product sales	$ 24,474	$ 10,804	$ 9,398
Royalty, contract and other revenues	416	398	304
Total revenues	24,890	11,202	9,702
Costs and Expenses [Abstract]
Cost of goods sold	3,788	2,859	2,471
Research and development expenses	2,854	2,120	1,760
Selling, general and administrative expenses	2,983	1,699	1,461
Total costs and expenses	9,625	6,678	5,692
Income from operations	15,265	4,524	4,010
Interest expense	(412)	(307)	(361)
Other income (expense), net	3	(9)	(37)
Income before provision for income taxes	14,856	4,208	3,612
Provision for income taxes	2,797	1,151	1,038
Net income	12,059	3,057	2,574
Net loss attributable to noncontrolling interest	42	18	18
Net income attributable to Gilead	$ 12,101	$ 3,075	$ 2,592
Net income per share attributable to Gilead common stockholders—basic	$ 7.95	$ 2.01	$ 1.71
Shares used in per share calculation—basic	1,522	1,529	1,515
Net income per share attributable to Gilead common stockholders—diluted	$ 7.35	$ 1.81	$ 1.64
Shares used in per share calculation—diluted	1,647	1,695	1,583