LEASES - Maturity of Payments for Operating and FInancing Leases (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease Liabilities, Payments Due [Abstract]
2019 (for the three months remaining in 2019)	$ 20
2020	70
2021	55
2022	36
2023	21
2024 and beyond	28
Total minimum lease payments	230
Less: interest	22
Present value of future minimum lease payments	208	$ 237
Less: current lease obligations	65
Long-term lease obligations	143		$ 0
Finance Lease Liabilities, Payments, Due [Abstract]
2019 (for the three months remaining in 2019)	2
2020	8
2021	8
2022	6
2023	4
2024 and beyond	2
Total minimum lease payments	30
Less: interest	4
Present value of future minimum lease payments	26
Less: current lease obligations	6
Long-term lease obligations	$ 20