Leases (Maturities of Lease Liabilities) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Operating Leases
2019	$ 50
2020	93
2021	77
2022	65
2023	58
After 2023	398
Gross Total	741
Imputed Discount	(233)
Total	508
Finance Leases
2019	4
2020	20
2021	20
2022	22
2023	148
After 2023	217
Gross Total	431
Imputed Discount	(159)
Total	$ 272