ACQUISITION, LICENSING AGREEMENTS AND ASSETS HELD FOR SALE - Narrative (Details) - USD ($)		3 Months Ended				6 Months Ended	12 Months Ended	15 Months Ended
	Sep. 21, 2020	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2021
Business Acquisition [Line Items]
Other (income) expense, net		$ (30,000,000)			$ 36,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations | Amoun
Business Acquisition [Line Items]
Impairment of long-lived assets		$ 68,000,000	$ 96,000,000					$ 164,000,000
Noncash cumulative foreign currency translation loss							$ 340,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations | Amoun | Subsequent Event | Forecast
Business Acquisition [Line Items]
Cash proceeds from divestiture						$ 740,000,000
Allegro
Business Acquisition [Line Items]
Potential asset acquisition, aggregate purchase price	$ 50,000,000
Potential asset acquisition, upfront payment included in aggregate purchase price	10,000,000
Potential asset acquisition, additional funding payment included in aggregate purchase price	$ 40,000,000
Other (income) expense, net				$ 10,000,000