Commitments, Contingencies, Guarantees, and Others - Unfunded Lending Commitments: Contractual Amount and Carrying Value (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Unfunded lending commitments, contractual amount	$ 414,499	$ 386,732
Off-balance sheet lending commitment, carrying value	149	176
Credit Card
Loss Contingencies [Line Items]
Unused commitments to extend credit, contractual amount	368,508	349,594
Other excluding credit card
Loss Contingencies [Line Items]
Unused commitments to extend credit, contractual amount	44,572	35,836
Off-balance sheet lending commitment, carrying value	125	144
Advised line of credit	3,900	1,800
Letter of credit
Loss Contingencies [Line Items]
Standby letters of credit and commercial letters of credit, contractual amount	1,419	1,302
Off-balance sheet lending commitment, carrying value	$ 24	$ 32