COMMITMENTS AND CONTINGENCIES - Schedule of Future Minimum Lease Payments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Feb. 29, 2020
Operating Leases
2020	$ 165
2021	82
2022	50
2023	33
2024	27
Thereafter	32
Total future minimum payments	389
Less: imputed interest	(23)
Total lease liabilities	366
Current portion	169	$ 0
Non-current portion	197
Finance Leases
2020	13
2021	3
2022	3
2023	3
2024	3
Thereafter	37
Total future minimum payments	62
Less: imputed interest	(14)
Total lease liabilities	48
Current portion	11
Non-current portion	37
Purchase Obligation, Fiscal Year Maturity [Abstract]
2021	152
2021	191
2022	181
2023	213
2024	195
Thereafter	910
Total future minimum payments	1,842
Total costs under take or pay and throughout obligation	$ 111	$ 132	$ 134
Subsequent Event
Purchase Obligation, Fiscal Year Maturity [Abstract]
Aggregate cost of apache				$ 171