Goodwill and Mortgage Servicing Rights - Mortgage Fees and Related Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Risk management:
Mortgage fees and related income	$ 309	$ 278
All other	6	15
CCB
CCB mortgage fees and related income
Production revenue	178	110
Operating revenue:
Loan servicing revenue	409	404
Changes in MSR asset fair value due to collection/realization of expected cash flows	(269)	(260)
Total operating revenue	140	144
Risk management:
Changes in MSR asset fair value due to market interest rates and other	56	(100)
Other changes in MSR asset fair value due to other inputs and assumptions in model	(18)	(27)
Changes in derivative fair value and other	(53)	136
Total risk management	(15)	9
Total net mortgage servicing revenue	125	153
Mortgage fees and related income	$ 303	$ 263