LICENSING AND OTHER ARRANGEMENTS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	$ (152)	$ (130)	$ (287)	$ (288)
Up-front Licensing Fee	0	0	0	(30)
Contingent and Regulatory Milestone Income	(2)	(5)	(2)	(46)
Amortization of Other Deferred Charges	(15)	(15)	(30)	(30)
Licensing and Other Arrangements Income	(253)	(181)	(485)	(433)
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	(9)	(6)	(12)	(11)
Keytruda Royalties
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	(204)	(155)	(396)	(316)
Tecentriq royalties
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	(23)	0	(45)	0
Diabetes business [Member]
Licensing Arrangements [Line Items]
Royalty Income, Nonoperating	$ (152)	$ (129)	$ (286)	$ (256)