v3.25.4
Loans and Allowance for Credit Losses - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2025
USD ($)
Loan
Dec. 31, 2024
USD ($)
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged $ 1,864,512,000 $ 2,110,755,000
Total charge-offs 12,140,000 28,437,000
Recorded investment of PCD Loans 29,800,000 43,800,000
Recorded investment, estimated allowance for credit loss 200,000 300,000
Recorded investment, PCD Discount (Premium) 2,000,000 3,000,000
Recovery of credit losses 12,461,000 18,467,000
Financing Receivable, Modified in Period, Amount 2,428,000 1,784,000
Financing receivable, allowance for credit loss, writeoff 12,140,000 28,437,000
Unfunded commitments 0 0
Mortgage loans with amortized cost 2,900,000 200,000
Accrued interest receivable 10,787,000 12,537,000
Accrued interest excluded from ACL 9,100,000 10,700,000
Interest income from nonaccrual loans $ 700,000 500,000
Number of residential mortgage loans in the process of foreclosure | Loan 7  
Payment Deferral [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Financing Receivable, Modified in Period, Amount $ 0 666,000
Doubtful [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 390,000 1,654,000
Grade 7 Substandard [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 75,460,000 64,697,000
Commercial and Residential Mortgages [Member] | Asset Pledged As Collateral Without Right [Member] | Federal Home Loan Bank Advances [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 695,100,000 797,900,000
Commercial and Industrial [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 271,158,000 354,904,000
Total charge-offs 9,385,000 24,005,000
Recovery of credit losses 9,638,000 16,598,000
Financing receivable, allowance for credit loss, writeoff 9,385,000 24,005,000
Commercial and Industrial [Member] | Payment Deferral [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Financing Receivable, Modified in Period, Amount 0 156,000
Commercial and Industrial [Member] | Asset Pledged As Collateral Without Right [Member] | FRB [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 72,800,000 91,600,000
Commercial and Industrial [Member] | Doubtful [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged 390,000 83,000
Commercial and Industrial [Member] | Grade 7 Substandard [Member]    
Loans and Leases Receivable Disclosure [Line Items]    
Loans pledged $ 22,537,000 $ 22,157,000