EQUITY METHOD INTERESTS - Summary of Combined Statement of Balance Sheet Equity Method Interests (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Current assets	$ 1,846	$ 1,961
Total assets	12,746	18,107	$ 21,582
Current liabilities	1,308	1,855
Equity	(645)	4,465	$ 8,812	$ 8,791
TOTAL LIABILITIES AND EQUITY	12,746	18,107
Equity Method Investment, Nonconsolidated Investee
Schedule of Equity Method Investments [Line Items]
Current assets	260	441
Noncurrent assets	7,678	6,435
Total assets	7,938	6,876
Current liabilities	206	478
Noncurrent liabilities	1,191	958
Equity	6,541	5,440
TOTAL LIABILITIES AND EQUITY	$ 7,938	$ 6,876