Leases Other Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Short-term Lease, Cost	$ 1	$ 3
Variable Lease, Cost	7	20
Operating cash flows from finance leases	0	0
Operating cash flows from operating leases	2	6
Financing cash flows from finance leases	0	0
Right-of-use assets obtained in exchange for new operating lease liabilities	20	25
Right-of-use assets obtained in exchange for new financing lease liabilities	$ 0	$ 1