Securities - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2023 USD ($) Security $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) Security $ / shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Debt and Equity Securities, FV-NI [Line Items]
Fair value of pledged securities	$ 129,100,000		$ 129,100,000		$ 110,100,000
Restricted stock investment in FHLB stock	1,000,000		1,000,000		2,900,000
Federal Home Loan Bank redemption of stock	$ 1,900,000		$ 1,900,000
Federal Home Loan Bank redemption par value per share | $ / shares	$ 100		$ 100
Federal Reserve Bank stock	$ 471,000		$ 471,000		471,000
Proceeds from sale of available-for-sale securities	$ 0	$ 0	$ 0	$ 0
Number of securities in an unrealized loss position, Total | Security	203		203
Number of securities in continuous unrealized loss position, 12 months or more | Security			183
Held to maturity security, allowance for credit loss	$ 0		$ 0
Total available-for-sale securities	145,330,000		145,330,000		$ 150,069,000
US Treasury Securities And US Government Sponsored Agency Bonds [Member]
Debt and Equity Securities, FV-NI [Line Items]
Total available-for-sale securities	100,000,000		100,000,000
Non-agency Debt Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Total available-for-sale securities	45,000,000		45,000,000
Non-agency Debt Securities [Member] | Non-rated Debt Securities [Member]
Debt and Equity Securities, FV-NI [Line Items]
Total available-for-sale securities	$ 5,000,000		$ 5,000,000