Fair Value of Financial Instruments - Financial Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]
Total Securities Available-for-Sale	$ 372,975	$ 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	87,512	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	87,512	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	282,323	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	282,323	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	3,140	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	3,140	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	87,512	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	87,512	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	130,108	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	130,108	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	86,320	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	86,320	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	69,035	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	65,895	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	3,140	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	$ 3,140	$ 3,345