Leases, Remaining Minimum Lease Payments (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating Leases
2020	$ 376
2021	250
2022	194
2023	160
2024	125
Thereafter	498
Total undiscounted lease payments	1,603
Less: Amount associated with discounting	313
Total lease liabilities	1,290
Finance Leases
2020	88
2021	86
2022	87
2023	91
2024	82
Thereafter	1,011
Total undiscounted lease payments	1,445
Less: Amount associated with discounting	654
Total lease liabilities	$ 791
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