DIVESTITURES, LICENSING AND OTHER ARRANGEMENTS - Licensing and Other Arrangements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	$ (171)	$ (135)
Contingent milestone income	(41)	0
Amortization of deferred income	(12)	(15)
Licensing and Other Arrangements Income	(306)	(232)
Immatics
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Upfront payments	150
Dragonfly
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Upfront payments	175
Keytruda Royalties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	(221)	(192)
Tecentriq royalties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	(25)	(22)
Other Royalties
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Royalty income, nonoperating	$ (7)	$ (3)