Commitments, Contingencies, Guarantees and Others - Unfunded Lending Commitments: Contractual Amount and Carrying Value (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Total unfunded lending commitments, contractual amount	$ 441,283	$ 409,314
Off-balance sheet lending commitment, carrying value	122	204
Credit Card:
Loss Contingencies [Line Items]
Unused commitments to extend credit, contractual amount	392,867	359,507
Other loan commitments
Loss Contingencies [Line Items]
Unused commitments to extend credit, contractual amount	46,951	48,405
Off-balance sheet lending commitment, carrying value	99	176
Advised line of credit	4,700	4,400
Letter of credit
Loss Contingencies [Line Items]
Standby letters of credit and commercial letters of credit, contractual amount	1,465	1,402
Off-balance sheet lending commitment, carrying value	$ 23	$ 28