Leases (Operating Lease Assets and Liabilities ) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Right-of-use assets	$ 1,745	$ 1,857
Operating lease, right-of-use asset, statement of financial position [Extensible Enumeration]	Other	Other
Lease liabilities	$ 1,998	$ 2,160
Operating lease, liability, statement of financial position [Extensible Enumeration]	Accrued expenses and other liabilities (b)	Accrued expenses and other liabilities (b)