ACQUISITIONS NARRATIVE (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended								12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	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	Nov. 17, 2020	Nov. 20, 2019
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired											$ 13,084	$ 24,777	$ 2,372
Revenues			$ 11,068	$ 10,540	$ 10,129	$ 10,781	$ 7,945	$ 6,007	$ 6,273	$ 5,920	42,518	26,145	22,561
Net (Loss)/Earnings			$ (10,027)	$ 1,878	$ (80)	$ (766)	(1,060)	$ 1,366	$ 1,439	$ 1,715	(8,995)	3,460	4,947
Business Acquisition, Transaction Costs		$ 657					$ 657					657
Employee Benefits and Share-based Compensation											$ 779	441	$ 221
MyoKardia Acquisition [Member]
Business Acquisition [Line Items]
Business Acquisition, Share Price														$ 225.00
Asset acquisition payment														$ 13,089
Charge for unvested stock awards	$ 482
Celgene [Member]
Business Acquisition [Line Items]
Business Acquisition, Share Price															$ 50.00
Business Combination, Potential Payment Per Share Based Upon Future Events															$ 9.00
Payments to Acquire Businesses, Gross												35,745
Payments to Acquire Businesses, Net of Cash Acquired												24,600
Employee Benefits and Share-based Compensation		$ 66
Celgene [Member]
Business Acquisition [Line Items]
Revenues												1,900
Net (Loss)/Earnings												$ 1,600