Annual report [Section 13 and 15(d), not S-K Item 405]

Qualified Affordable Housing Project Investments - Additional Information (Detail)

v3.25.4
Qualified Affordable Housing Project Investments - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Investments in Affordable Housing Projects [Line Items]      
Unfunded commitments related to investments $ 17.8 $ 13.8  
Investment, Proportional Amortization Method, Elected, Statement of Financial Position [Extensible Enumeration] Prepaid Expense and Other Assets Prepaid Expense and Other Assets  
Qualified affordable housing project investments $ 29.7 $ 22.1  
Investment commitments expected to be paid 2025 2026 2027 2028 2029    
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Income or Comprehensive Income [Extensible Enumeration] Income Tax Expense (Benefit) Income Tax Expense (Benefit)  
Investment Program, Proportional Amortization Method, Applied, Amortization Expense, Statement of Cash Flows [Extensible Enumeration]     Income Tax Expense (Benefit)
Qualified affordable housing project investments, amortization expense recognized $ 2.5 $ 1.8 $ 1.9