v3.25.2
Fair Value Measurements - Fair Values of Assets and Liabilities (Significant Unobservable Level 3 Inputs Recurring Basis) (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Derivative Assets $ 1,997   $ 2,472
Derivative liabilities (2,266)   (2,798)
Servicing rights      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Servicing rights $ 1,629 $ 1,731  
Servicing rights | Minimum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Prepayment speed 0.00% 0.00%  
OAS (bps) 0.0335 0.0420  
Servicing rights | Maximum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Prepayment speed 100.00% 100.00%  
OAS (bps) 0.1821 0.1833  
Servicing rights | Fixed | Weighted-Average      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Prepayment speed 6.50% 5.60%  
OAS (bps) 0.0433 0.0448  
Servicing rights | Adjustable | Weighted-Average      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Prepayment speed 17.20% 22.10%  
OAS (bps) 0.0723 0.0693  
IRLCs, net      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Derivative Assets $ 7 $ 5  
IRLCs, net | Minimum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Loan closing rates 18.60% 18.80%  
IRLCs, net | Maximum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Loan closing rates 96.00% 96.00%  
IRLCs, net | Weighted-Average      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Loan closing rates 82.20% 82.30%  
Swap      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Derivative liabilities $ (145) $ (164)  
Swap | Minimum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Timing of the resolution of the Covered Litigation Jun. 30, 2027 Dec. 31, 2026  
Swap | Maximum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Timing of the resolution of the Covered Litigation Jun. 30, 2028 Mar. 31, 2028  
Swap | Weighted-Average      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Timing of the resolution of the Covered Litigation Dec. 31, 2027 Jun. 30, 2027  
Residential Mortgage      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Loans measured at FV $ 107 $ 109 $ 108
Residential Mortgage | Minimum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Interest rate risk factor (52.00%) (26.00%)  
Credit risk factor 0.00% 0.00%  
Residential Mortgage | Maximum      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Interest rate risk factor 6.10% 5.00%  
Credit risk factor 0.80% 0.60%  
Residential Mortgage | Weighted-Average      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis      
Interest rate risk factor (11.40%) (14.10%)  
Credit risk factor 0.10% 0.10%