ACQUISITIONS, DIVESTITURES AND LICENSING ARRANGEMENTS ASSET ACQUISITION (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 17, 2020
Business Acquisition [Line Items]
MyoKardia Asset Acquisition IPRD Charge		$ 11,438	$ 0	$ 0
Research and development [Member]
Business Acquisition [Line Items]
Charge for unvested stock awards		241
Selling, General and Administrative Expenses [Member]
Business Acquisition [Line Items]
Charge for unvested stock awards		241
MyoKardia Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Share Price					$ 225.00
Asset acquisition payment					$ 13,089
Charge for unvested stock awards	$ 482
Deferred income taxes acquired through an asset acquisition					295
Cash consideration for outstanding shares	12,030
Cash consideration for stock awards	1,059
Transaction cost	53
Consideration to be allocated	12,660
Other intangible assets acquired through an asset acquisition					11,553
Cash and cash equivalents acquired through an asset acquisition					861
Other assets acquired through an asset acquisition					177
Other liabilities assumed through an asset acquisition					(226)
Total assets acquired, net through an asset acquisition					$ 12,660
Forbius [Member]
Business Acquisition [Line Items]
Asset acquisition payment	185	185
Contingent and Regulatory Milestone Payments	815	815
Deferred income taxes acquired through an asset acquisition	7	7
Cormorant [Member]
Business Acquisition [Line Items]
Contingent and Regulatory Milestone Payments	$ 100	$ 100		$ 60