Leases Lease Liability Maturities (Details) $ in Millions	Sep. 30, 2019 USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Remainder of 2019	$ 54
2020	176
2021	152
2022	131
2023	80
Thereafter	206
Total lease payments	799
Less: imputed interest	(135)
Operating lease liability	664
Finance Lease, Liability, Payment, Due [Abstract]
Remainder of 2019	6
2020	19
2021	14
2022	14
2023	12
Thereafter	67
Total lease payments	132
Less: imputed interest	(39)
Financing lease liability	$ 93