SIGNIFICANT ACCOUNTING POLICIES - Revenue Recognition, Variable Consideration Provisions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 2,384	$ 2,546
Acquisition of Synergy	16
Current period provision	5,287	5,887
Payments and credits	(5,637)	(6,049)
Balance at End of Year	2,050	2,384
Discounts and Allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	175	167
Acquisition of Synergy	0
Current period provision	776	865
Payments and credits	(769)	(857)
Balance at End of Year	182	175
Returns
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	813	863
Acquisition of Synergy	3
Current period provision	113	293
Payments and credits	(238)	(343)
Balance at End of Year	691	813
Rebates
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	1,024	1,094
Acquisition of Synergy	12
Current period provision	2,265	2,551
Payments and credits	(2,374)	(2,621)
Balance at End of Year	927	1,024
Chargebacks
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	209	274
Acquisition of Synergy	0
Current period provision	1,938	1,966
Payments and credits	(1,979)	(2,031)
Balance at End of Year	168	209
Distribution Fees
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	163	148
Acquisition of Synergy	1
Current period provision	195	212
Payments and credits	(277)	(197)
Balance at End of Year	$ 82	$ 163