Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 106,153	$ 84,738
Interest-bearing deposits	74,619	310,634
Debt Securities, Available-for-Sale	787,415	1,041,380
Debt Securities, Held-to-maturity	474,790	541,311
Other investments	15,456	12,838
Loans Held for sale, Amount	13,811	18,583
Loans and Leases Receivable, Net of Deferred Income	7,348,917	6,839,230
Deposits	8,077,649	7,982,498
Short-term borrowings	97,932	138,315
Subordinated debt	170,897	170,775
Long-term debt	5,041	5,573
Capital Lease Obligations	5,551	5,921
Estimate of Fair Value Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	106,153	84,738
Interest-bearing deposits	74,619	310,634
Debt Securities, Available-for-Sale	787,415	1,041,380
Debt Securities, Held-to-maturity	395,160	536,651
Other investments	15,456	12,838
Loans Held for sale, Amount	13,811	18,583
Loans and Leases Receivable, Net of Deferred Income	7,377,557	7,169,768
Deposits	8,065,102	7,980,101
Short-term borrowings	85,814	136,473
Subordinated debt	157,682	175,040
Long-term debt	4,954	6,065
Capital Lease Obligations	5,551	5,921
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	106,153	84,738
Interest-bearing deposits	74,619	310,634
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	787,415	1,041,380
Debt Securities, Held-to-maturity	395,160	536,651
Other investments	14,286	11,668
Loans Held for sale, Amount	13,811	18,583
Loans and Leases Receivable, Net of Deferred Income	22,672	42,538
Deposits	8,065,102	7,980,101
Short-term borrowings	85,814	136,473
Subordinated debt	0	0
Long-term debt	4,954	6,065
Capital Lease Obligations	5,551	5,921
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	1,170	1,170
Loans Held for sale, Amount	0	0
Loans and Leases Receivable, Net of Deferred Income	7,354,885	7,127,230
Deposits	0	0
Short-term borrowings	0	0
Subordinated debt	157,682	175,040
Long-term debt	0	0
Capital Lease Obligations	0	0
Cash and due from banks	106,153	84,738
Interest-bearing deposits	74,619	310,634
Debt Securities, Available-for-Sale	787,415	1,041,380
Debt Securities, Held-to-maturity	474,790	541,311
Other investments	15,456	12,838
Loans and Leases Receivable, Net of Deferred Income	7,348,917	6,839,230	$ 6,732,580
Deposits	8,077,649	7,982,498
Short-term borrowings	97,932	138,315
Subordinated debt	170,897	170,775
Long-term debt	5,041	5,573
Capital Lease Obligations	5,551	5,921
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	14,286	11,668
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	$ 1,170	$ 1,170