Loans - Consumer, Excluding Credit Card Loan Portfolio, Residential Real Estate, Active and Suspended Foreclosure (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Financing Receivable, Past Due [Line Items]
Carrying value	$ 1,264,093	$ 1,280,870	$ 1,084,850
Consumer, excluding credit card
Financing Receivable, Past Due [Line Items]
Carrying value	389,592	397,275	$ 300,447
Consumer, excluding credit card | Residential real estate
Financing Receivable, Past Due [Line Items]
Carrying value	319,984	326,409
Consumer, excluding credit card | Residential real estate | In process of active or suspended foreclosure
Financing Receivable, Past Due [Line Items]
Carrying value	$ 608	$ 566