RESTRUCTURING NARRATIVE (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)	Sep. 30, 2020
Celgene Integration [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 3,000
Restructuring and Related Cost, Cost Incurred to Date	2,400
Cash outlays	$ 2,500
Restructuring and Related Cost, Number of Positions Eliminated	320	1,400
MyoKardia Acquisition Plan
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 150
Restructuring and Related Cost, Cost Incurred to Date	113
Operating Model 2020 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date	$ 1,500