Leases - Maturities of Lease Liabilities, Topic 842 (Details) $ in Millions	Jun. 30, 2019 USD ($)
Finance Leases
2020	$ 427
2021	387
2022	281
2023	150
2024	47
Thereafter	1
Total lease payments	1,293
Less: imputed interest	(77)
Total payments	1,216
Real Estate
Operating Leases
2020	310
2021	367
2022	287
2023	207
2024	157
Thereafter	281
Total lease payments	1,609
Less: imputed interest	(139)
Total payments	1,470
Equipment
Operating Leases
2020	124
2021	92
2022	30
2023	5
2024	1
Thereafter	0
Total lease payments	252
Less: imputed interest	(7)
Total payments	$ 245