Leases Lease Liability Maturities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Operating Lease Liabilities, Payments Due [Abstract]
Remainder of 2019	$ 98
2020	172
2021	149
2022	128
2023	84
Thereafter	199
Total lease payments	830
Less: imputed interest	(145)
Operating lease liability	685
Finance Lease Liabilities, Payments, Due [Abstract]
Remainder of 2019	8
2020	18
2021	14
2022	13
2023	12
Thereafter	68
Total lease payments	133
Less: imputed interest	(40)
Financing lease liability	$ 93