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

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.25.4
Summary of Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2025
USD ($)
Branch
Segment
shares
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Apr. 25, 2024
shares
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Number of reportable segments | Segment 1      
Accrued interest receivable on available-for-sale debt securities $ 3,700,000 $ 3,600,000    
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Accrued interest Accrued interest    
Retained earnings $ 394,335,000 $ 350,869,000    
Impairment of goodwill 0      
Bank-owned life insurance $ 56,697,000 57,168,000    
Stock options, expiration term from date of grant 10 years      
Number of shares authorized for repurchase (percent)       5.00%
Number of shares authorized for repurchase under program (shares) | shares 2,300,000     1,500,000
Shares repurchased (shares) | shares 393,298      
Shares repurchased $ 9,404,000 6,314,000 $ 4,084,000  
Share Repurchase Program, Authorized, Number of Shares | shares 2,300,000     1,500,000
Share Repurchase Program, Remaining Authorized, Number of Shares | shares 837,202      
Unrealized loss on sale of debt securities $ 0      
Allowance for credit loss on available for sale securities $ 0 $ 0    
ShareRepurchaseProgram [Member]        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Number of shares authorized for repurchase under program (shares) | shares 1,500,000      
Share Repurchase Program, Authorized, Number of Shares | shares 1,500,000      
Minimum        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Period of continuous service 3 years      
Maximum        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Period of continuous service 5 years      
Split Dollar Death Benefit Agreement        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Bank-owned life insurance $ 4,100,000      
Full Service        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Number of branches | Branch 32      
Loan Production        
Financing Receivable, Recorded Investment, Past Due [Line Items]        
Number of branches | Branch 5