LEASES - Schedule of Lease Maturities (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jan. 01, 2019
Operating Leases
2019	$ 144
2020	171
2021	152
2022	132
2023	110
Later years	339
Total lease payments	1,048
Less: Imputed interest	188
Total operating lease liabilities	860
Less: Current obligations	146	$ 147
Long-term lease obligations	714	$ 715
Finance Leases
2019	120
2020	122
2021	64
2022	16
2023	13
Later years	123
Total lease payments	458
Less: Imputed interest	93
Total finance lease liabilities	365
Less: Current obligations	141
Long-term lease obligations	224
Total
2019	264
2020	293
2021	216
2022	148
2023	123
Later years	462
Total lease payments	1,506
Less: Imputed interest	281
Total lease obligations	1,225
Less: Current obligations	287
Long-term lease obligations	$ 938