Leases (Supplemental Balance Sheet Information) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Property leases
Operating lease ROU assets	$ 2,350	$ 2,405
Short-term operating lease liabilities	533	555
Long-term operating lease liabilities	1,852	1,884
Operating lease liabilities	$ 2,385	$ 2,439
Weighted average remaining lease term	8 years 2 months 12 days	8 years 2 months 12 days
Weighted average discount rate	4.39%	4.30%
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accounts Payable and Accrued Liabilities, Current	Accounts Payable and Accrued Liabilities, Current