Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	$ 84,738	$ 100,009
Interest-bearing deposits	310,634	256,572
Securities available for sale	1,041,380	831,223
Debt Securities, Held-to-maturity	541,311	361,844
Other investments	12,838	12,227
Premises and Equipment		442
Loans	6,839,230	6,761,183	$ 6,189,148
Deposits	7,982,498	7,438,666
Short-term borrowings	138,315	117,373	$ 201,853
Long-term debt	5,573	56,258
Subordinated Debentures outstanding, Amount	170,775	170,612
Capital lease obligation	5,921	6,385
Loans Held for Sale	18,583	33,436
Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Securities available for sale	0	0
Other investments	0
Premises and Equipment		0
Loans Held for Sale	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Securities available for sale	1,041,380	831,223
Other investments	11,668	10,557
Premises and Equipment		442
Loans Held for Sale	18,583	33,436
Level 3 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Securities available for sale	0	0
Premises and Equipment		0
Loans Held for Sale	0	0
Carrying Amount [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	84,738	100,009
Interest-bearing deposits	310,634	256,572
Securities available for sale	1,041,380	831,223
Debt Securities, Held-to-maturity	541,311	361,844
Other investments	12,838	12,227
Loans held for sale	18,583	33,436
Loans	6,839,230	6,761,183
Deposits	7,982,498	7,438,666
Short-term borrowings	138,315	117,373
Long-term debt	5,573	56,258
Subordinated Debentures outstanding, Amount	170,775	170,612
Capital lease obligation	5,921	6,385
Estimated Fair Value [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	84,738	100,009
Interest-bearing deposits	310,634	256,572
Securities available for sale	1,041,380	831,223
Debt Securities, Held-to-maturity	536,651	369,851
Other investments	12,838	12,227
Loans held for sale	18,583	33,436
Loans	7,169,768	7,202,763
Deposits	7,980,101	7,440,906
Short-term borrowings	136,473	117,037
Long-term debt	6,065	57,881
Subordinated Debentures outstanding, Amount	175,040	165,665
Capital lease obligation	5,921	6,385
Estimated Fair Value [Member] \| Level 1 [Member]
Fair Value Measurements Of Financial Instruments [Line Items]
Cash and due from banks	84,738	100,009
Interest-bearing deposits	310,634	256,572
Securities available for sale	0	0
Debt Securities, Held-to-maturity	0	0
Other investments	0	0
Loans held for sale	0	0
Loans	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
Securities available for sale	1,041,380	831,223
Debt Securities, Held-to-maturity	536,651	369,851
Other investments	11,668	10,557
Loans held for sale	18,583	33,436
Loans	42,538	35,543
Deposits	7,980,101	7,440,906
Short-term borrowings	136,473	117,037
Long-term debt	6,065	57,881
Subordinated Debentures outstanding, Amount	0	0
Capital lease obligation	5,921	6,385
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
Securities available for sale	0	0
Debt Securities, Held-to-maturity	0	0
Other investments	1,170	1,670
Loans held for sale	0	0
Loans	7,127,230	7,167,220
Deposits	0	0
Short-term borrowings	0	0
Long-term debt	0	0
Subordinated Debentures outstanding, Amount	175,040	165,665
Capital lease obligation	$ 0	$ 0

Fair Value Measurements Of Financial Instruments [Line Items]

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