Goodwill, Mortgage Servicing Rights, and Other Intangible Assets - Mortgage Fees and Related Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Risk management:
Mortgage fees and related income	$ 383	$ 402	$ 1,024	$ 1,025
All other	11	12	42	15
CCB
CCB mortgage fees and related income
Production revenue	173	154	434	441
Operating revenue:
Loan servicing revenue	409	409	1,233	1,226
Changes in MSR asset fair value due to collection/realization of expected cash flows	(265)	(273)	(796)	(795)
Total operating revenue	144	136	437	431
Risk management:
Changes in MSR asset fair value due to market interest rates and other	(3)	(251)	(44)	134
Other changes in MSR asset fair value due to other inputs and assumptions in model	34	70	1	82
Changes in derivative fair value and other	24	281	154	(78)
Total risk management	55	100	111	138
Total net mortgage servicing revenue	199	236	548	569
Mortgage fees and related income	$ 372	$ 390	$ 982	$ 1,010