EARNINGS PER SHARE - Summary of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Net income attributable to Gilead	$ 5,665	$ 4,592	$ 6,225
Shares used in basic earnings per share attributable to Gilead calculation (in shares)	1,248	1,255	1,256
Dilutive effect of stock options and equivalents (in shares)	10	7	6
Shares used in diluted earnings per share attributable to Gilead calculation (in shares)	1,258	1,262	1,262
Basic earnings per share attributable to Gilead (in dollars per share)	$ 4.54	$ 3.66	$ 4.96
Diluted earnings per share attributable to Gilead (in dollars per share)	$ 4.50	$ 3.64	$ 4.93