v3.25.4
Investments - Additional Information (Detail)
12 Months Ended
Dec. 31, 2025
USD ($)
Security
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Schedule Of Available For Sale Securities [Line Items]      
Number of unrealized loss position, available-for-sale securities | Security 76    
Number of unrecognized loss position, held-to-maturity securities | Security 0    
Unrealized gain (loss) for investments $ 159,000 $ 197,000 $ 104,000
Unfunded Commitment in qualified affordable housing projects $ 10,208,000 12,067,000 19,315,000
Commitments expected to be fulfill The Company expects to fulfill these commitments during the years 2026 through 2040.    
Tax credits from investment in affordable housing $ 1,994,000 $ 1,793,000 $ 1,327,000
Investment Program Proportional Amortization Method Elected Income Tax Credit and Other Income Tax Benefit Before Amortization Statement of Income or Comprehensive Income Extensible Enumeration Not Disclosed Flag true true true
Investment Program Proportional Amortization Method Elected Income Tax Credit And Other Income Tax Benefit Before Amortization Statement Of Cash Flows Extensible Enumeration Not Disclosed Flag true true true
Amortized Cost of Securities Reclassified from Government-Sponsored Residential Mortgage-Backed Securities to Small Business Administration Loan Pools   $ 23,670,000  
Fair Value of securities reclassified from government-sponsored residential mortgage-backed securities to small business administration loan pools   23,662,000  
Private Label Residential Mortgage-Backed Securities [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Number of positions, available-for-sale securities | Security 1    
Allowance for credit losses $ 0    
Corporate [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Number of positions, available-for-sale securities | Security 40    
Allowance for credit losses $ 0    
State and Political Subdivisions [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Number of positions, debt securities | Security 61    
Allowance for credit losses $ 0    
Not Included in Proportional Amortization [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Contingent contributions for investment tax credit $ 0 $ 0  
Simplified Supervisory Formula Approach [Member] | Private Label Residential Mortgage-Backed Securities [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Percentage of risk 20.00%    
Nationally Recognized Statistical Ratings Organization [Member] | State and Political Subdivisions [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Percentage of risk 65.00%    
General Obligation Bonds [Member] | State and Political Subdivisions [Member]      
Schedule Of Available For Sale Securities [Line Items]      
Percentage of risk 44.00%