v3.26.3
FAIR VALUE - Mortgage Servicing Rights - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Level 3 | Recurring          
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]          
Transfers from level 3 $ 41 $ 0 $ 41 $ 0  
Servicing Assets          
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]          
Sensitivity analysis of fair value, impact of 10 percent adverse change in prepayment speed, increase (decrease) (2)   (2)    
Sensitivity analysis of fair value, impact of 20 percent adverse change in prepayment speed, increase (decrease) (4)   (4)    
Sensitivity analysis of fair value, impact of 10 percent adverse change in discount rate, increase (decrease) (3)   (3)    
Sensitivity analysis of fair value, impact of 20 percent adverse change in discount rate, increase (decrease) (6)   (6)    
Residential mortgages          
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]          
Principal balance of loans serviced for others $ 6,300   $ 6,300   $ 6,600