Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating leases:
Operating lease right-of-use assets	$ 19,122	$ 20,729
Current portion of operating lease liabilities	1,646	1,638
Long-term operating lease liabilities	18,177	18,757
Total operating lease liabilities	19,823	20,395
Finance leases:
Property and equipment, gross	1,375	1,107
Accumulated depreciation	(188)	(106)
Property and equipment, net	1,187	1,001
Current portion of long-term debt	50	33
Long-term debt	1,250	1,050
Total finance lease liabilities	$ 1,300	$ 1,083
Weighted average remaining lease term (in years)
Operating leases	12 years 9 months 18 days	13 years 3 months 18 days
Finance leases	20 years	20 years 3 months 18 days
Weighted average discount rate
Operating leases	4.40%	4.50%
Finance leases	5.00%	5.60%