Leases Lease Cost and Supplemental Information (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($) Rate	Jun. 30, 2019 USD ($) Rate
Leases [Abstract]
Operating Lease, Cost	$ 9	$ 18
Short-term Lease, Cost	2	5
Finance Lease, Right-of-Use Asset, Amortization	1	1
Finance Lease, Interest Expense	0	1
Variable Lease, Cost	1	2
Finance Lease, Principal Payments		2
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 1	$ 1
Operating Lease, Weighted Average Remaining Lease Term	8 years 9 months 26 days	8 years 9 months 26 days
Finance Lease, Weighted Average Remaining Lease Term	2 years	2 years
Lessee, Operating Lease, Discount Rate | Rate	12.18%	12.18%
Lessee, Finance Lease, Discount Rate | Rate	7.42%	7.42%
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 0	$ 3