v3.26.1
Mortgage Banking Activities, Assumptions and Sensitivity of Residential MSRs (Details) - Residential mortgage servicing rights [Member]
$ in Millions
3 Months Ended 12 Months Ended
Mar. 31, 2026
USD ($)
$ / loan
Dec. 31, 2025
USD ($)
$ / loan
Mar. 31, 2025
USD ($)
Dec. 31, 2024
USD ($)
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption [Line Items]        
Mortgage servicing rights, carried at fair value $ 5,608 $ 5,696 $ 6,536 $ 6,844
Expected weighted-average life (in years) 6 years 3 months 18 days 6 years 3 months 18 days    
Key assumptions [Abstract]        
Prepayment rate assumption 8.10% 8.00%    
Impact on fair value from 10% adverse change $ (159) $ (163)    
Impact on fair value from 25% adverse change $ (383) $ (394)    
Discount rate assumption 9.30% 9.10%    
Impact on fair value from 100 basis point increase $ (233) $ (243)    
Impact on fair value from 200 basis point increase $ (446) $ (465)    
Cost to service assumption ($ per loan) | $ / loan 94 96    
Impact on fair value from 10% adverse change $ (103) $ (106)    
Impact on fair value from 25% adverse change $ (259) $ (266)