Short-Term Borrowed Funds - Summary of Short-Term Borrowed Funds (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Short Term Debt [Line Items]
Short-term borrowed funds	$ 1,414,000	$ 1,379,000
Short-term borrowed funds, weighted average rates at year end	3.69%	4.56%
Short-term borrowed funds, average balance during year	$ 4,618,000	$ 1,077,000
Short-term borrowed funds, weighted average rate during year	4.77%	4.29%
Federal Funds Purchased [Member]
Short Term Debt [Line Items]
Short-term borrowed funds, average balance during year	$ 2,000	$ 4,000
Short-term borrowed funds, weighted average rate during year	5.82%	5.90%
Master Notes and Other Short Term Borrowings [Member]
Short Term Debt [Line Items]
Short-term borrowed funds	$ 1,414,000	$ 1,379,000
Short-term borrowed funds, weighted average rates at year end	3.69%	4.56%
Short-term borrowed funds, average balance during year	$ 1,351,000	$ 1,073,000
Short-term borrowed funds, weighted average rate during year	4.36%	4.28%
Shortterm Debt Maximum Monthend Outstanding Amount	$ 1,463,000	$ 2,094,000
Notes Payable [Member]
Short Term Debt [Line Items]
Short-term borrowed funds, average balance during year	$ 3,265,000
Short-term borrowed funds, weighted average rate during year	4.93%