Federal Funds Purchased and Securities Sold Under Agreement to Repurchase - Daily Securities Sold under Agreement to Repurchase (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period	$ 28,200
Daily Securities Sold Under Agreement to Repurchase [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period		$ 1,115
Weighted Average Rate End of Period	0.00%	0.95%
Maximum Amount Borrowings Outstanding Month End	$ 1,694	$ 1,450
Approximate Average Outstanding in Period	$ 1,176	$ 1,169
Approximate Weighted Average Interest Rate For the Period	1.19%	0.43%
Term CDs Sold Under Agreement to Repurchase [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount Outstanding at End of Period	$ 28,218	$ 30,518
Weighted Average Rate End of Period	0.98%	0.97%
Maximum Amount Borrowings Outstanding Month End	$ 28,968	$ 34,504
Approximate Average Outstanding in Period	$ 28,918	$ 31,573
Approximate Weighted Average Interest Rate For the Period	3.97%	2.54%