ALLIANCES (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Alliance Statement [Line Items]
Total Revenues	$ 11,703		$ 10,129		$ 22,776	$ 20,910
Cost of products sold	2,452	[1]	2,699	[1]	5,293	6,361
Other (income)/expense, net	(2)		(736)		(704)	427
Receivables - from alliance partners	9,017				9,017		$ 8,501
Accounts payable - to alliance partners	3,609				3,609		2,713
Collaborative Arrangement [Member]
Alliance Statement [Line Items]
Total Revenues	2,964		2,364		5,988	5,192
Cost of products sold	1,346		1,050		2,743	2,356
Selling, General and Administrative Expense	(48)		(38)		(97)	(78)
Research and Development Expense	736		233		743	279
Other (income)/expense, net	(14)		(16)		(19)	(31)
Receivables - from alliance partners	349				349		343
Accounts payable - to alliance partners	2,032				2,032		1,093
Deferred income from alliance	349				349		$ 366
Collaborative Arrangement [Member] | Eisai
Alliance Statement [Line Items]
Upfront Payments Made To Collaborative Partner						650
Consideration for contingent development and regulatory approval					2,500
Net product sales [Member]
Alliance Statement [Line Items]
Total Revenues	11,405		9,817		22,203	20,358
Net product sales [Member] | Collaborative Arrangement [Member]
Alliance Statement [Line Items]
Total Revenues	2,805		2,201		5,687	4,924
Collaborative Arrangement [Member] | Collaborative Arrangement [Member]
Alliance Statement [Line Items]
Total Revenues	$ 159		$ 163		$ 301	$ 268

[1] Excludes amortization of acquired intangible assets