Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 120,267	$ 84,738
Interest-bearing deposits	179,533	310,634
Debt Securities, Available-for-Sale	863,622	1,041,380
Debt Securities, Held-to-maturity	492,229	541,311
Other investments	13,665	12,838
Loans Held for sale, Amount	12,876	18,583
Loans and Leases Receivable, Net of Deferred Income	7,119,754	6,839,230
Deposits	8,053,545	7,982,498
Short-term borrowings	88,923	138,315
Subordinated debt	170,856	170,775
Long-term debt	5,221	5,573
Capital Lease Obligations	5,675	5,921
Estimate of Fair Value Measurement [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	120,267	84,738
Interest-bearing deposits	179,533	310,634
Debt Securities, Available-for-Sale	863,622	1,041,380
Debt Securities, Held-to-maturity	437,880	536,651
Other investments	13,665	12,838
Loans Held for sale, Amount	12,876	18,583
Loans and Leases Receivable, Net of Deferred Income	7,269,337	7,169,768
Deposits	8,044,453	7,980,101
Short-term borrowings	80,376	136,473
Subordinated debt	163,810	175,040
Long-term debt	5,317	6,065
Capital Lease Obligations	5,675	5,921
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	120,267	84,738
Interest-bearing deposits	179,533	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	863,622	1,041,380
Debt Securities, Held-to-maturity	437,880	536,651
Other investments	12,495	11,668
Loans Held for sale, Amount	12,876	18,583
Loans and Leases Receivable, Net of Deferred Income	23,938	42,538
Deposits	8,044,453	7,980,101
Short-term borrowings	80,376	136,473
Subordinated debt	0	0
Long-term debt	5,317	6,065
Capital Lease Obligations	5,675	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	7,245,399	7,127,230
Deposits	0	0
Short-term borrowings	0	0
Subordinated debt	163,810	175,040
Long-term debt	0	0
Capital Lease Obligations	0	0
Cash and due from banks	120,267	84,738
Interest-bearing deposits	179,533	310,634
Debt Securities, Available-for-Sale	863,622	1,041,380
Debt Securities, Held-to-maturity	492,229	541,311
Other investments	13,665	12,838
Loans and Leases Receivable, Net of Deferred Income	7,119,754	6,839,230	$ 6,740,535
Deposits	8,053,545	7,982,498
Short-term borrowings	88,923	138,315
Subordinated debt	170,856	170,775
Long-term debt	5,221	5,573
Capital Lease Obligations	5,675	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	12,495	11,668
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Other investments	$ 1,170	$ 1,170