Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 122,982	$ 124,254
Interest-bearing deposits	214,088	29,990
Debt Securities, Available-for-Sale	817,603	762,661
Debt Securities, Held-to-maturity	429,558	461,162
Other investments	48,979	26,414
Loans Held for sale, Amount	33,127	11,869
Loans and Leases Receivable, Net of Deferred Income	8,901,725	7,642,143
Deposits	9,241,065	8,005,469
Short-term borrowings	544,060	372,694
Subordinated debt	177,679	170,937
Long-term debt	4,310	4,862
Capital Lease Obligations	5,028	5,425
Estimate of Fair Value Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	122,982	124,254
Interest-bearing deposits	214,088	29,990
Debt Securities, Available-for-Sale	817,603	762,661
Debt Securities, Held-to-maturity	341,646	386,205
Other investments	48,979	26,414
Loans Held for sale, Amount	33,127	11,869
Loans and Leases Receivable, Net of Deferred Income	8,683,023	7,639,721
Deposits	9,227,226	7,992,012
Short-term borrowings	539,688	363,135
Subordinated debt	149,252	156,621
Long-term debt	4,142	4,781
Capital Lease Obligations	5,028	5,425
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	122,982	124,254
Interest-bearing deposits	214,088	29,990
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	817,603	762,661
Debt Securities, Held-to-maturity	341,646	386,205
Other investments	42,797	25,244
Loans Held for sale, Amount	33,127	11,869
Loans and Leases Receivable, Net of Deferred Income	21,934	23,140
Deposits	9,227,226	7,992,012
Short-term borrowings	539,688	363,135
Subordinated debt	0	0
Long-term debt	4,142	4,781
Capital Lease Obligations	5,028	5,425
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	1,170
Loans Held for sale, Amount	0	0
Loans and Leases Receivable, Net of Deferred Income	8,661,089	7,616,581
Deposits	0	0
Short-term borrowings	0	0
Subordinated debt	149,252	156,621
Long-term debt	0	0
Capital Lease Obligations	0	0
Cash and due from banks	122,982	124,254
Interest-bearing deposits	214,088	29,990
Debt Securities, Available-for-Sale	817,603	762,661
Debt Securities, Held-to-maturity	429,558	461,162
Other investments	48,979	26,414
Loans and Leases Receivable, Net of Deferred Income	8,901,725	7,642,143
Deposits	9,241,065	8,005,469
Short-term borrowings	544,060	372,694
Subordinated debt	177,679	170,937
Long-term debt	4,310	4,862
Capital Lease Obligations	5,028	5,425
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	42,797	25,244
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	$ 6,182	$ 1,170