Derivative Financial Instruments - Net Gains (Losses) Recorded in the Condensed Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used for Risk Management and Other Business Purposes (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Interest rate contracts \| Mortgage banking net revenue \| MSR portfolio
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ (11)	$ 19
Forward contracts related to residential mortgage loans measured at fair value \| Mortgage banking net revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	9	(9)
Foreign exchange contracts \| Other noninterest income
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	10	0
Equity contracts \| Other noninterest income \| Swap
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 8	$ (18)

Derivative Financial Instruments - Net Gains (Losses) Recorded in the Condensed Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used for Risk Management and Other Business Purposes (Details) - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2026

Mar. 31, 2025

Interest rate contracts | Mortgage banking net revenue | MSR portfolio

Derivative Instruments, Gain (Loss)

Net gains (losses) recorded in earnings

$ (11)

$ 19

Forward contracts related to residential mortgage loans measured at fair value | Mortgage banking net revenue

Derivative Instruments, Gain (Loss)

Net gains (losses) recorded in earnings

(9)