LICENSING ARRANGEMENTS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty Income, Nonoperating	$ (23)	$ (11)	$ (41)
Up-front licensing fee	(30)	(29)	(61)
Contingent regulatory milestone income	(72)	(31)	(37)
Amortization of Other Deferred Charges	(58)	(58)	(57)
Licensing and other arrangements income	(883)	(674)	(539)
Keytruda royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty Income, Nonoperating	(681)	(545)	(343)
Tecentriq royalties
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Royalty Income, Nonoperating	(19)	$ 0	$ 0
Proceeds from out-licensed arrangements	324
Patent Settlement Income	239
Dragonfly [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payments for licensing and alliance arrangements	475
Payment for Additional Targets Made To Collaborative Partner	75
Collaborative Arrangement Contingent Payments Maximum Exposure	$ 2,700