Fair Value Measurement - Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	$ 654,616	$ 648,067
Equity securities	2,573	2,421
Swap asset	2,590	6,330
(Level 1) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	36,126	64,571
(Level 1) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member] \| U.S. Treasury securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	36,126	64,571
(Level 2) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	618,490	583,496
Equity securities	2,573	2,421
Loans held for sale, at fair value	8,012
(Level 2) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member] \| Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale, at fair value		665
Swap asset	3,684	5,308
Swap liability	6,222	11,638
(Level 2) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member] \| Obligations of U.S. Government agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	29,620	32,816
(Level 2) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member] \| Obligations of States and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	321,606	325,119
(Level 2) [Member] \| Assets Measured at Fair Value on a Recurring Basis [Member] \| Mortgage-backed Securities in Government Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities available for sale	267,264	225,561
(Level 3) [Member] \| Assets Measured at Fair Value on a Nonrecurring Basis [Member] \| Collateral-Dependent Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 6,982	$ 19,177

Fair value portion of asset recognized for present right to economic benefit.

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