v3.26.1
Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Carrying Amount [Member]    
Fair Value Measurements Of Financial Instruments [Line Items]    
Cash and due from banks $ 110,327 $ 103,280
Interest-bearing deposits 69,308 77,082
Debt Securities, Available-for-Sale 1,092,201 1,014,194
Debt Securities, Held-to-maturity 574,542 519,422
Other investments 34,372 38,295
Loans Held for sale, Amount 44,764 271,452
Financing Receivable, before Allowance for Credit Loss 9,467,229 9,508,039
Deposits 10,260,061 10,250,969
Short-term borrowings 137,946 147,966
Subordinated debt 121,683 128,466
Long-term debt 0 129,555
Capital Lease Obligations 3,401 3,721
Estimate of Fair Value Measurement [Member]    
Fair Value Measurements Of Financial Instruments [Line Items]    
Cash and due from banks 110,327 103,280
Interest-bearing deposits 69,308 77,082
Debt Securities, Available-for-Sale 1,092,201 1,014,194
Debt Securities, Held-to-maturity 521,253 470,665
Other investments 34,372 38,295
Loans Held for sale, Amount 44,941 271,452
Financing Receivable, before Allowance for Credit Loss 9,486,192 9,657,464
Deposits 10,252,398 10,248,485
Short-term borrowings 136,787 147,926
Subordinated debt 116,636 121,747
Long-term debt 0 130,108
Capital Lease Obligations 3,401 3,721
Estimate of Fair Value Measurement [Member] | Level 1 [Member]    
Fair Value Measurements Of Financial Instruments [Line Items]    
Cash and due from banks 110,327 103,280
Interest-bearing deposits 69,308 77,082
Debt Securities, Available-for-Sale 0 0
Debt Securities, Held-to-maturity 0 0
Other investments 0 0
Loans Held for sale, Amount 0 0
Financing Receivable, before Allowance for Credit Loss 0 0
Deposits 0 0
Short-term borrowings 0 0
Subordinated debt 0 0
Long-term debt 0 0
Capital Lease Obligations 0 0
Estimate of Fair Value Measurement [Member] | Level 2 [Member]    
Fair Value Measurements Of Financial Instruments [Line Items]    
Cash and due from banks 0 0
Interest-bearing deposits 0 0
Debt Securities, Available-for-Sale 1,092,201 1,014,194
Debt Securities, Held-to-maturity 521,253 470,665
Other investments 29,190 32,563
Loans Held for sale, Amount 44,941 271,452
Financing Receivable, before Allowance for Credit Loss 42,730 40,617
Deposits 10,252,398 10,248,485
Short-term borrowings 136,787 147,926
Subordinated debt 0 0
Long-term debt 0 130,108
Capital Lease Obligations 3,401 3,721
Estimate of Fair Value Measurement [Member] | Level 3 [Member]    
Fair Value Measurements Of Financial Instruments [Line Items]    
Cash and due from banks 0 0
Interest-bearing deposits 0 0
Debt Securities, Available-for-Sale 0 0
Debt Securities, Held-to-maturity 0 0
Other investments 5,182 5,732
Loans Held for sale, Amount 0 0
Financing Receivable, before Allowance for Credit Loss 9,443,462 9,616,847
Deposits 0 0
Short-term borrowings 0 0
Subordinated debt 116,636 121,747
Long-term debt 0 0
Capital Lease Obligations 0 0
Cash and due from banks 110,327 103,280
Interest-bearing deposits 69,308 77,082
Debt Securities, Available-for-Sale 1,092,201 1,014,194
Debt Securities, Held-to-maturity 574,542 519,422
Other investments 34,372 38,295
Financing Receivable, before Allowance for Credit Loss 9,467,229 9,508,039
Deposits 10,260,061 10,250,969
Short-term borrowings 137,946 147,966
Subordinated debt 121,683 128,466
Long-term debt 0 129,555
Capital Lease Obligations $ 3,401 $ 3,721