FAIR VALUE OF FINANCIAL INSTRUMENTS - Carrying Values and Fair Values of Non-Current Financial Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	$ 159	$ 117
Other noncurrent liabilities	(2,366)	(2,236)
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	159	117
Total noncurrent financial assets	159	117
Senior Notes	(8,031)	(6,441)
Commercial paper/Credit Facility	(900)	(3,197)
Other long-term debt	(126)	(174)
Other noncurrent liabilities	(426)	(196)
Total noncurrent financial liabilities	(9,483)	(10,008)
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior, mezzanine, and other loans	142	112
Total noncurrent financial assets	142	112
Senior Notes	(8,941)	(6,712)
Commercial paper/Credit Facility	(900)	(3,197)
Other long-term debt	(128)	(179)
Other noncurrent liabilities	(426)	(196)
Total noncurrent financial liabilities	$ (10,395)	$ (10,284)