ACQUISITION, LICENSING AGREEMENTS AND ASSETS HELD FOR SALE - Narrative (Details) $ in Millions		3 Months Ended			6 Months Ended		10 Months Ended	12 Months Ended
	Mar. 06, 2019 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) product	Dec. 31, 2019 USD ($) product	Dec. 31, 2018 USD ($)	Mar. 31, 2020 USD ($)
Business Acquisition [Line Items]
Advisory, legal, valuation, accounting and other similar services, included in other expense, net		$ 107		$ 8	$ 130	$ 5
Assets reclassified, held and used		$ 31,396			$ 31,396		$ 33,863	$ 33,863
Disposal Group, Held-for-sale, Not Discontinued Operations | Certain Products For Disposal, September 2019
Business Acquisition [Line Items]
Revenue associated with products for disposal								$ 14	$ 19
Impairment of long-lived assets classified as held for sale			$ 8
Disposal Group, Held-for-sale, Not Discontinued Operations | Certain Products For Disposal, September 2019 | Restatement Adjustment
Business Acquisition [Line Items]
Assets reclassified, held for sale										$ 39
Assets reclassified, held and used										$ 39
Disposal Group, Held-for-sale, Not Discontinued Operations | Certain Products For Disposal, September 2019 | Diversified Products
Business Acquisition [Line Items]
Number of products for disposal | product							1	1
Synergy Pharmaceuticals Inc.
Business Acquisition [Line Items]
Cash payments to acquire certain assets and assumed liabilities	$ 180
Revenue of acquiree							$ 55
Operating results of acquiree							$ 0
Pro forma revenue						0		$ 0
Pro forma operating results						0		$ 0
Advisory, legal, valuation, accounting and other similar services, included in other expense, net						$ 8