LEASES - Maturities of Operating and Finance Lease Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Finance Leases
2020			$ 7
2021			7
2022			7
2023			6
2024			6
Thereafter			78
Total minimum lease payments			111
Less: imputed interest			(57)
Total finance lease liabilities			54
Operating Leases
2020			112
Operating lease rent expense	$ 152	$ 155
2021			96
2022			80
2023			67
2024			54
Thereafter			267
Total minimum lease payments			676
Less: imputed interest			(65)
Total operating lease liabilities			$ 611