Investment and Equity Securities - Additional Information (Detail) - USD ($)	Jun. 30, 2024	Dec. 31, 2023
Schedule of Available-for-sale Securities [Line Items]
Federal Reserve stock owned by Company	$ 959,000	$ 959,000
Federal Home Loan Bank stock (FHLB)	750,000	712,000
Allowance for credit losses for available for sale securities	0
Securities held to maturity	0
Securities available for sale pledged as collateral on public deposits/short-term borrowings	142,300,000	$ 137,100,000
Federal Reserve Bank
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale pledged as collateral on public deposits/short-term borrowings	6,700,000
Past Due 30 Days or More
Schedule of Available-for-sale Securities [Line Items]
Securities held to maturity current	$ 0