Leases Maturities of Lease Liabilities (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 10,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Two	34,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Three	26,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Four	23,000,000
Lessee, Operating Lease, Liability, Payments, Due Year Five	20,000,000
Lessee, Operating Lease, Liability, Payments, Due after Year Five	146,000,000
Operating Leases, Future Sublease Income	0	$ 0
Lessee, Operating Lease, Liability, Payments, Due	259,000,000
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(46,000,000)
Operating Lease, Liability	213,000,000
Finance Lease, Liability, Payment, Due [Abstract]
Finance Lease, Liability, Payments, Remainder of Fiscal Year	11,000,000
Finance Lease, Liability, Payments, Due Year Two	40,000,000
Finance Lease, Liability, Payments, Due Year Three	39,000,000
Finance Lease, Liability, Payments, Due Year Four	30,000,000
Finance Lease, Liability, Payments, Due Year Five	22,000,000
Finance Lease, Liability, Payments, Due after Year Five	86,000,000
Finance Lease, Future Minimum Sublease Rentals	0
Finance Lease, Liability, Payment, Due	228,000,000
Finance Lease, Liability, Undiscounted Excess Amount	(82,000,000)
Finance Lease, Liability	146,000,000	$ 167,000,000
Finance lease commitments that have not yet commenced	$ 0