LICENSING AND OTHER ARRANGEMENTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	$ (160)	$ (192)	$ (447)	$ (480)
Up-front Licensing Fee	0	0	0	(30)
Contingent and Regulatory Milestone Income	(10)	(16)	(12)	(62)
Amortization of Other Deferred Charges	3	(14)	(27)	(44)
Licensing and Other Arrangements Income	(265)	(211)	(750)	(644)
Agenus
Licensing Arrangements [Line Items]
License and Other Arrangements Upfront Payments	200		200
Contingent and Regulatory Milestone Payments	1,400		1,400
Other Royalties
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	(21)	(5)	(33)	(16)
Keytruda Royalties
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	(215)	(176)	(611)	(492)
Tecentriq royalties
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	(22)	0	(67)	0
Diabetes business [Member]
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	$ (159)	$ (148)	$ (445)	$ (404)