ALLIANCES (Otsuka) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues	$ 11,068	$ 10,540	$ 10,129	$ 10,781	$ 7,945	$ 6,007	$ 6,273	$ 5,920	$ 42,518		$ 26,145		$ 22,561
Cost of products sold									11,773	[1]	8,078	[1]	6,467
Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues									9,979		10,541		9,006
Cost of products sold									4,485		4,169		3,439
Collaborative Arrangement [Member] | Otsuka [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Collaboration Distribution Fees									$ 294
Collaboration Distribution Fee Percentage	1.00%								1.00%
Cost of products sold											302		297
Net product sales [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues									$ 41,321		25,174		21,581
Net product sales [Member] | Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues									$ 9,364		9,944		8,359
Net product sales [Member] | Collaborative Arrangement [Member] | Otsuka [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues											$ 1,800		$ 1,700

[1] Excludes amortization of acquired intangible assets.