Mortgage Servicing Rights - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Transfers and Servicing [Abstract]
Residential mortgage loans serviced for others including subserviced mortgages with no corresponding MSRs asset	$ 216,100		$ 216,100		$ 216,600
Gain (loss) on fair value changes of MSRs due to changes in valuation assumptions and derivatives used to economically hedge MSRs	12	$ (10)	10	$ 11
Loan servicing and ancillary fees	$ 173	$ 170	$ 526	$ 517