Fair Value of Financial Instruments - Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	$ 363,225	$ 390,789
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	86,127	94,678
Level 1 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	86,127	94,678
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	273,989	292,766
Level 2 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	273,989	292,766
Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	3,109	3,345
Level 3 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	3,109	3,345
U.S. Treasury [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	86,127	94,678
U.S. Treasury [Member] | Level 1 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	86,127	94,678
U.S. Government Agencies [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	127,891	139,767
U.S. Government Agencies [Member] | Level 2 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	127,891	139,767
Mortgage-backed Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	81,656	86,927
Mortgage-backed Securities [Member] | Level 2 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	81,656	86,927
State and Local Governments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	67,551	69,417
State and Local Governments [Member] | Level 2 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	64,442	66,072
State and Local Governments [Member] | Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	3,109	3,345
State and Local Governments [Member] | Level 3 [Member] | Fair Value on a Recurring Basis [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	$ 3,109	$ 3,345