Leases - Remaining Minimum Lease Payments (Details) $ in Millions	Mar. 31, 2019 USD ($)
Operating Leases
Remainder of 2019	$ 13
2020	14
2021	12
2022	9
2023	6
Thereafter	4
Total lease payments	58
Less: imputed interest	(8)
Lease liability	50
Financing Leases
Remainder of 2019	8
2020	11
2021	11
2022	11
2023	10
Thereafter	53
Total lease payments	104
Less: imputed interest	(35)
Lease liability	$ 69