Leases - Schedule of Maturities of Operating and Finance Leases Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases
2019 (excluding the three months ended March 31, 2019)	$ 43		$ 54
2020	42		42
2021	32		34
2022	24		26
2023	20		21
Thereafter	115		117
Total lease payments	276		294
Less imputed interest	(62)
Total operating lease liabilities	214	$ 220
Finance Lease Liabilities, Payments, Due [Abstract]
2019 (excluding the three months ended March 31, 2019)	2		5
2020	3		5
2021	2		5
2022	2		4
2023	2		4
Thereafter	6		6
Total lease payments	17		$ 29
Less imputed interest	(2)
Total finance lease liabilities	$ 15