Leases (Future Minimum Lease Payments Under Non-Cancelable Operating and Capital Leases Along with Associated Sub-Lease Income) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Operating and Capital Leases
2019	$ 168
2020	133
2021	106
2022	82
2023	58
2024 and thereafter	138
Total	685
Sub-lease Income
2019	1
2020	1
2021	1
2022	0
2023	0
2024 and thereafter	0
Total	3
Capital Leases	$ 26