Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($)
$ in Millions
Dec. 31, 2021
Dec. 31, 2020
Operating leases:    
Operating lease assets $ 908 $ 844
Short-term operating lease liabilities 170 152
Operating lease liabilities 752 696
Total operating lease liabilities 922 848
Finance leases:    
Property and equipment, gross 403 392
Accumulated depreciation (156) (135)
Property and equipment, net 247 257
Short-term borrowings and current maturities of long-term debt 57 59
Long-term debt 180 193
Total finance lease liabilities $ 237 $ 252
Weighted-average remaining lease term:    
Operating leases 8 years 7 years
Finance leases 6 years 6 years
Weighted-average discount rate:    
Operating leases 4.86% 5.26%
Finance leases 1.98% 2.33%
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Short-term borrowings and current maturities of long-term debt Short-term borrowings and current maturities of long-term debt
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration] Long-term debt Long-term debt