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		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 45	$ (75)	$ (17)	$ (110)
Interest rate contracts | Mortgage banking net revenue | MSR portfolio
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	45	(75)	(17)	(110)
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	(7)	6	(1)	9
Interest-only strips | Other noninterest income
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	0	0	0	(3)
Foreign exchange contracts | Other noninterest income
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(1)	5	5	1
Equity contracts | Other noninterest income | Swap
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ (47)	$ (10)	$ (87)	$ (72)