Commitments and Contingencies - Future Minimum Rental Payments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Leases
2020	$ 19
2021	19
2022	19
2023	19
2024	11
Thereafter	62
Total lease payments	149
Less: imputed interest	19
Operating lease liabilities	130	$ 95
Finance Leases
2020	1
2021	1
2022	0
2023	0
2024	0
Thereafter	0
Total lease payments	2
Less: imputed interest	0
Finance lease liabilities	$ 2
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019			$ 9
2020			9
2021			8
2022			8
2023			9
Thereafter			$ 72