ACQUISITIONS, DIVESTITURES, LICENSING AND OTHER ARRANGEMENTS - Licensing and Other Arrangements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront licensing fees	$ 0	$ 0	$ (34)
Contingent milestone income	(91)	(50)	(18)
Amortization of deferred income	(51)	(53)	(39)
Total	(1,488)	(1,283)	(1,067)
Keytruda Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty income, nonoperating	(1,186)	(1,001)	(841)
Tecentriq Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty income, nonoperating	(107)	(93)	(90)
Biohaven
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Biohaven sublicense income	0	(55)	0
Other Royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty income, nonoperating	$ (53)	$ (31)	$ (45)