EARNINGS (LOSS) PER SHARE - Summary of the Calculation of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings Per Share [Abstract]
Net income (loss) attributable to Gilead	$ 1,614	$ 1,045	$ (2,556)	$ 2,055
Shares used in basic earnings (loss) per share attributable to Gilead calculation (in shares)	1,247	1,249	1,247	1,249
Dilutive effect of stock options and equivalents (in shares)	4	9	0	11
Shares used in diluted earnings (loss) per share attributable to Gilead calculation (in shares)	1,251	1,258	1,247	1,260
Basic earnings (loss) per share attributable to Gilead (in dollars per share)	$ 1.29	$ 0.84	$ (2.05)	$ 1.65
Diluted earnings (loss) per share attributable to Gilead (in dollars per share)	$ 1.29	$ 0.83	$ (2.05)	$ 1.63