Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 103,280	$ 105,051
Interest-bearing deposits	77,082	28,358
Debt Securities, Available-for-Sale	1,014,194	1,147,623
Debt Securities, Held-to-maturity	519,422	405,639
Other investments	38,295	30,954
Financing receivable, before allowance for credit loss	9,508,039	8,983,754
Deposits	10,250,969	9,678,019
Short-term borrowings	147,966	80,139	$ 597,835
Long-term debt	129,555	130,353
Subordinated Debentures outstanding, Amount	128,466	128,305
Capital lease obligation	3,721	4,327
Loans Held for Sale	46,071	51,991
Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Debt Securities, Available-for-Sale	0	0
Loans Held for Sale	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Debt Securities, Available-for-Sale	1,014,194	1,147,623
Loans Held for Sale	46,071	51,991
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Debt Securities, Available-for-Sale	0	0
Loans Held for Sale	0	0
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	103,280	105,051
Interest-bearing deposits	77,082	28,358
Debt Securities, Available-for-Sale	1,014,194	1,147,623
Debt Securities, Held-to-maturity	519,422	405,639
Other investments	38,295	30,954
Loans held for sale	271,452	51,991
Financing receivable, before allowance for credit loss	9,508,039	8,983,754
Deposits	10,250,969	9,678,019
Short-term borrowings	147,966	80,139
Long-term debt	129,555	130,353
Subordinated Debentures outstanding, Amount	128,466	128,305
Capital lease obligation	3,721	4,327
Estimated Fair Value [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	103,280	105,051
Interest-bearing deposits	77,082	28,358
Debt Securities, Available-for-Sale	1,014,194	1,147,623
Debt Securities, Held-to-maturity	470,665	336,719
Other investments	38,295	30,954
Loans held for sale	271,452	52,219
Financing receivable, before allowance for credit loss	9,657,464	8,999,020
Deposits	10,248,485	9,672,358
Short-term borrowings	147,926	79,151
Long-term debt	130,108	129,880
Subordinated Debentures outstanding, Amount	121,747	115,747
Capital lease obligation	3,721	4,327
Estimated Fair Value [Member] | Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	103,280	105,051
Interest-bearing deposits	77,082	28,358
Debt Securities, Available-for-Sale	0	0
Debt Securities, Held-to-maturity	0	0
Other investments	0	0
Loans held for sale	0	0
Financing receivable, before allowance for credit loss	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Subordinated Debentures outstanding, Amount	0	0
Capital lease obligation	0	0
Estimated Fair Value [Member] | Fair Value, Inputs, 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	1,014,194	1,147,623
Debt Securities, Held-to-maturity	470,665	336,719
Other investments	32,563	25,222
Loans held for sale	271,452	52,219
Financing receivable, before allowance for credit loss	40,617	39,407
Deposits	10,248,485	9,672,358
Short-term borrowings	147,926	79,151
Long-term debt	130,108	129,880
Subordinated Debentures outstanding, Amount	0	0
Capital lease obligation	3,721	4,327
Estimated Fair Value [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	5,732	5,732
Loans held for sale	0	0
Financing receivable, before allowance for credit loss	9,616,847	8,959,613
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Subordinated Debentures outstanding, Amount	121,747	115,747
Capital lease obligation	$ 0	$ 0