v3.26.1
Fair Value - Level 3 Unobservable Inputs, Mortgage Servicing Liabilities (Details) - Mortgage servicing liabilities - Level 3
6 Months Ended 12 Months Ended
Jun. 30, 2026
USD ($)
Y
Dec. 31, 2025
USD ($)
Y
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption    
Fair value $ 1,522,000 $ 1,572,000
Unpaid principal balance of underlying loans $ 14,370,000 $ 15,298,000
Servicing fee rate (as a percent) 0.25% 0.25%
Annual per-loan cost of servicing $ 804 $ 853
Annual total prepayment speed    
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption    
Input 0.138 0.142
Life    
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption    
Input | Y 5.6 5.5
Option-adjusted spread    
Sensitivity Analysis of Fair Value of Interests Continued to be Held by Transferor, Servicing Assets or Liabilities, Impact of Adverse Change in Assumption    
Input 0.093 0.091