Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 77,179	$ 125,436
Interest-bearing deposits	233,188	21,557
Debt Securities, Available-for-Sale	1,023,711	1,020,986
Debt Securities, Held-to-maturity	464,708	419,009
Other investments	25,397	50,871
Loans Held for sale, Amount	31,895	29,820
Loans and Leases Receivable, Net of Deferred Income	8,999,870	8,968,761
Deposits	9,446,403	9,192,309
Short-term borrowings	546,541	597,835
Subordinated debt	177,803	177,741
Long-term debt	3,932	4,122
Capital Lease Obligations	4,755	4,894
Estimate of Fair Value Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	77,179	125,436
Interest-bearing deposits	233,188	21,557
Debt Securities, Available-for-Sale	1,023,711	1,020,986
Debt Securities, Held-to-maturity	393,749	350,595
Other investments	25,397	50,871
Loans Held for sale, Amount	31,895	29,820
Loans and Leases Receivable, Net of Deferred Income	8,907,184	8,860,736
Deposits	9,440,446	9,187,655
Short-term borrowings	540,267	594,670
Subordinated debt	156,341	151,525
Long-term debt	3,832	4,041
Capital Lease Obligations	4,755	4,894
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	77,179	125,436
Interest-bearing deposits	233,188	21,557
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
Loans and Leases Receivable, Net of Deferred Income	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	1,023,711	1,020,986
Debt Securities, Held-to-maturity	393,749	350,595
Other investments	19,215	44,689
Loans Held for sale, Amount	31,895	29,820
Loans and Leases Receivable, Net of Deferred Income	27,025	25,215
Deposits	9,440,446	9,187,655
Short-term borrowings	540,267	594,670
Subordinated debt	0	0
Long-term debt	3,832	4,041
Capital Lease Obligations	4,755	4,894
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	6,182	6,182
Loans Held for sale, Amount	0	0
Loans and Leases Receivable, Net of Deferred Income	8,880,159	8,835,521
Deposits	0	0
Short-term borrowings	0	0
Subordinated debt	156,341	151,525
Long-term debt	0	0
Capital Lease Obligations	0	0
Cash and due from banks	77,179	125,436
Interest-bearing deposits	233,188	21,557
Debt Securities, Available-for-Sale	1,023,711	1,020,986
Debt Securities, Held-to-maturity	464,708	419,009
Other investments	25,397	50,871
Loans and Leases Receivable, Net of Deferred Income	8,999,870	8,968,761
Deposits	9,446,403	9,192,309
Short-term borrowings	546,541	597,835
Subordinated debt	177,803	177,741
Long-term debt	3,932	4,122
Capital Lease Obligations	4,755	4,894
Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	0	0
Level 2 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	19,215	44,689
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	$ 6,182	$ 6,182