ACQUISITIONS, DIVESTITURES, LICENSING AND OTHER ARRANGEMENTS - Licensing and Other Arrangements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Contingent milestone income	$ 0	$ 0	$ (36)	$ (46)
Amortization of deferred income	(12)	(18)	(39)	(41)
Total	(365)	(374)	(1,068)	(967)
Keytruda royalties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	(315)	(268)	(878)	(732)
Tecentriq royalties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	(24)	(24)	(78)	(68)
Biohaven
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	0	(55)	0	(55)
Other royalties and licensing income
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	$ (14)	$ (9)	$ (37)	$ (25)