Securities - Amortized Cost and Fair Value of Securities with Gross Unrealized Gains and Losses (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 412,451	$ 439,186
Gross Unrealized Gains	120	69
Gross Unrealized Losses	(39,596)	(48,466)
Fair Value	372,975	390,789
U.S. Treasury [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	95,215	104,507
Gross Unrealized Losses	(7,703)	(9,829)
Fair Value	87,512	94,678
U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	144,105	156,817
Gross Unrealized Losses	(13,997)	(17,050)
Fair Value	130,108	139,767
Mortgage-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	98,348	101,068
Gross Unrealized Losses	(12,028)	(14,141)
Fair Value	86,320	86,927
State and Local Governments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	74,783	76,794
Gross Unrealized Gains	120	69
Gross Unrealized Losses	(5,868)	(7,446)
Fair Value	$ 69,035	$ 69,417

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).

+ References

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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