Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($) Lease	Dec. 31, 2018 USD ($)
Operating Leased Assets [Line Items]
Operating Lease Cost	$ 5
Operating Lease, Payments	5
Operating lease right-of-use asset	12
Future Minimum Payments Due	$ 3
Lease Term ( in years )	6 years 4 months 17 days
Term of Contract ( in years )	5 years
Renewal Term ( in years )	15 years
Less: imputed interest	$ 12	$ 0
Operating lease liabilities	16	0
Operating lease liabilities, noncurrent	$ 54	$ 0
Number of Operating Lease ( in leases ) | Lease	2
Minimum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	1 year
Maximum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	9 years 6 months