Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Operating Leased Assets [Line Items]
Renewal Term	15 years	15 years
Operating lease expense	$ 5	$ 14
Operating lease payments	4	13
Total operating lease liabilities	69	69
New Operating Lease Liabilities	$ 4	$ 21
Lease Term ( in years )	6 years 2 months 12 days	6 years 2 months 12 days
Less: imputed interest	$ 10	$ 10
Operating lease liabilities	17	17	$ 0
Operating lease liabilities, noncurrent	52	52	0
Operating Lease, Right-of-Use Asset	$ (57)	$ (57)	$ 0
Minimum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	1 year	1 year
Maximum
Operating Leased Assets [Line Items]
Term of Contract ( in years )	9 years	9 years