Leases - Supplemental Operating Lease Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Leases [Abstract]
Document Period End Date	Sep. 30, 2019
Operating lease right-of-use assets	$ 107	$ 0
Accrued liabilities	25
Operating lease liabilities	91	$ 0
Operating lease liabilities	116
Operating Lease, Right-of-Use Asset, in Exchange for Lease Obligations	7
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases for the nine months period	$ 25
Operating Lease, Weighted Average Remaining Lease Term	5 years
Weighted average discount rate	5.00%