Securities - Available for Sale Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Total securities available for sale	$ 684,355	$ 682,351
Gross Unrealized Gains	1,948	819
Gross Unrealized Losses	(58,596)	(67,768)
Fair Value	627,707	615,402
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Total securities available for sale	66,781	66,495
Gross Unrealized Gains	22	20
Gross Unrealized Losses	(4,290)	(5,486)
Fair Value	62,513	61,029
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Total securities available for sale	356,250	350,104
Gross Unrealized Gains	1,902	784
Gross Unrealized Losses	(27,514)	(33,640)
Fair Value	330,638	317,248
Mortgage-backed Securities in Government Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Total securities available for sale	261,324	265,752
Gross Unrealized Gains	24	15
Gross Unrealized Losses	(26,792)	(28,642)
Fair Value	$ 234,556	$ 237,125

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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