Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Leases
2022	$ 347
2023	284
2024	223
2025	175
2026	115
Thereafter	355
Total lease payments	1,499
Less: interest	(247)
Total	1,252
Less: current portion	(299)	$ (241)
Operating lease liabilities	953	903
Finance Leases
2022	28
2023	25
2024	26
2025	26
2026	26
Thereafter	191
Total lease payments	322
Less: interest	(80)
Total	242
Less: current portion	(16)	(14)
Long-term portion	$ 226	$ 241