Leases Maturities of Lease Liabilities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Leases [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 3
Finance Lease, Liability, Payments, Remainder of Fiscal Year	9
Lessee, Operating Lease, Liability, Payments, Due Year Two	5
Finance Lease, Liability, Payments, Due Year Two	16
Lessee, Operating Lease, Liability, Payments, Due Year Three	5
Finance Lease, Liability, Payments, Due Year Three	16
Lessee, Operating Lease, Liability, Payments, Due Year Four	5
Finance Lease, Liability, Payments, Due Year Four	16
Lessee, Operating Lease, Liability, Payments, Due Year Five	5
Finance Lease, Liability, Payments, Due Year Five	14
Lessee, Operating Lease, Liability, Payments, Due after Year Five	53
Finance Lease, Liability, Payments, Due after Year Five	250
Lessee, Operating Lease, Liability, Payments, Due	76
Finance Lease, Liability, Payments, Due	321
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(36)
Finance Lease, Liability, Undiscounted Excess Amount	(167)
Operating Lease, Liability	40
Finance Lease, Liability	$ 154