Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Statement of Other Comprehensive Income [Abstract]
Net Income	$ 671,035	$ 737,538	$ 1,814,640	$ 2,127,300
Net foreign currency translation gain (loss)	5,090	(3,958)	7,346	(1,122)
Net unrealized gain (loss), net of tax impact of $(848) and $3,681 for the three months ended September 30, 2012 and 2011, and $(660) and $(2,634) for the nine months ended September 30, 2012 and 2011, respectively	1,476	(24,786)	1,146	(24,124)
Reclassifications to net income, net of tax impact of $1,396 and $(1,531) for the three months ended September 30, 2012 and 2011, and $849 and $(4,203) for the nine months ended September 30, 2012 and 2011, respectively	2,429	(2,656)	32,979	(7,160)
Net change	3,905	(27,442)	34,125	(31,284)
Net unrealized gain (loss), net of tax impact of $3,180 and $(5,031) for the three months ended September 30, 2012 and 2011, and $460 and $3,366 for the nine months ended September 30, 2012 and 2011, respectively	(67,674)	107,044	(9,084)	(66,481)
Reclassification to net income, net of tax impact of $(1,760) and $1,978 for the three months ended September 30, 2012 and 2011, and $(3,156) and $2,655 for the nine months ended September 30, 2012 and 2011, respectively	(37,449)	42,094	(62,338)	52,433
Net change	(105,123)	149,138	(71,422)	(14,048)
Other Comprehensive Income (Loss), Net of Tax	(96,128)	117,738	(29,951)	(46,454)
Comprehensive Income	574,907	855,276	1,784,689	2,080,846
Comprehensive Loss Attributable to Noncontrolling Interest	4,470	3,586	14,385	11,192
Comprehensive Income Attributable to Gilead	$ 579,377	$ 858,862	$ 1,799,074	$ 2,092,038