REVENUE RECOGNITION - Variable Consideration Provisions (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	$ 1,813	$ 2,050
Current period provisions	2,713	2,377
Payments and credits	(2,546)	(2,586)
Reserve ending balance	1,980	1,841
Discounts and Allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	190	182
Current period provisions	306	293
Payments and credits	(296)	(316)
Reserve ending balance	200	159
Returns
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	575	691
Current period provisions	77	54
Payments and credits	(119)	(124)
Reserve ending balance	533	621
Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	779	927
Current period provisions	1,227	1,018
Payments and credits	(1,025)	(1,096)
Reserve ending balance	981	849
Chargebacks
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	184	168
Current period provisions	993	917
Payments and credits	(1,012)	(939)
Reserve ending balance	165	146
Distribution Fees
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Reserve beginning balance	85	82
Current period provisions	110	95
Payments and credits	(94)	(111)
Reserve ending balance	$ 101	$ 66