Leases - Maturities of Operating and Finance Lease Liabilities (Details) $ in Millions	Sep. 30, 2019 USD ($)
Financing Leases
2019 (remaining three months)	$ 18
2020	70
2021	68
2022	64
2023	62
Thereafter	883
Total financing lease payments	1,165
Less: imputed interest	(547)
Total lease liabilities	618
Operating Leases
2019 (remaining three months)	679
2020	2,688
2021	2,567
2022	2,408
2023	2,297
Thereafter	17,165
Total operating lease payments	27,804
Less: imputed interest	(7,180)
Total lease liabilities	20,624
Total
2019 (remaining three months)	697
2020	2,758
2021	2,635
2022	2,472
2023	2,359
Thereafter	18,048
Total lease payments	28,969
Less: imputed interest	(7,727)
Total lease liabilities	21,242
Future noncancelable subleases, future minimum payments	320
Leases, amount due in excess of remaining estimated economic life	$ 2,300