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

Summary of Significant Accounting Policies - Additional Information (Detail)

v3.25.0.1
Summary of Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2024
USD ($)
Branch
Segment
shares
Dec. 31, 2023
USD ($)
Jan. 24, 2019
shares
Financing Receivable, Recorded Investment, Past Due [Line Items]      
Number of reportable segments | Segment 1    
Accrued interest receivable on available-for-sale debt securities $ 3,600,000 $ 3,300,000  
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] Accrued interest Accrued interest  
Retained earnings $ 350,869,000 $ 319,048,000  
Impairment of intangible assets 0    
Goodwill impairment loss 0    
Bank-owned life insurance $ 57,168,000 56,335,000  
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     1,500,000
Shares repurchased (shares) | shares 369,500    
Shares repurchased $ 6,314,000 4,084,000  
Unrealized loss on sale of debt securities 0    
Allowance for credit loss on available for sale securities $ 0 $ 0  
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 $ 4,300,000    
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 8