Leases (Reconciliation of Undiscounted Cash Flows to the Operating and Finance Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Leases
2022	$ 289
2023	227
2024	184
2025	121
2026	96
Thereafter	728
Total future lease payments	1,645
Less imputed interest	302
Present value of future lease payments	1,343
Less current portion of lease liabilities	258	$ 262
Long-term lease liabilities	$ 1,085	$ 1,149
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
ROU assets	$ 1,257	$ 1,328
Finance Leases
2022	92
2023	45
2024	27
2025	25
2026	24
Thereafter	202
Total future lease payments	415
Less imputed interest	78
Present value of future lease payments	337
Less current portion of lease liabilities	79	68
Long-term lease liabilities	258	255
ROU assets	$ 319	$ 333
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other liabilities	Other liabilities
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets