Leases, Remaining Minimum Lease Payments (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Operating Leases
2019	[1]	$ 108
2020		349
2021		236
2022		183
2023		150
Thereafter		598
Total undiscounted lease payments		1,624
Less amount associated with discounting		321
Total lease liabilities		1,303
Finance Leases
2019	[1]	22
2020		87
2021		85
2022		85
2023		89
Thereafter		1,078
Total undiscounted lease payments		1,446
Less amount associated with discounting		661
Total lease liabilities		$ 785
Operating Leases
2019			$ 359
2020			245
2021			178
2022			146
2023			123
Thereafter			514
Total undiscounted lease payments			1,565
Capital Leases
2019			69
2020			65
2021			62
2022			64
2023			65
Thereafter			957
Total undiscounted lease payments			1,282
Less amount associated with discounting			676
Total lease liabilities			$ 606

[1] The amounts as of September 30, 2019 are for the remaining three months of 2019.