Allowances for Loan Losses - Summary of Impaired Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Impaired [Line Items]
With an allowance recorded, Recorded Investment		$ 0
With an allowance recorded, Unpaid Principal Balance		0
With an allowance recorded, Related Allowance	$ 20	0
Total, Recorded Investment	7,313	751
Total, Unpaid Principal Balance	7,370	840
Total, Related Allowance	20	0
With no related allowance recorded, Average Recorded Investment	7,376	759
With no related allowance recorded, Interest Recognized	293	20
With an allowance recorded, Average Recorded Investment	23	0
With an allowance recorded, Interest Recognized	1	0
Total, Average Recorded Investment	7,399	759
Total, Interest Recognized	294	20
Agriculture Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	300
With no related allowance recorded, Unpaid Principal Balance	300	0
With an allowance recorded, Recorded Investment	0	0
With an allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Related Allowance	0	0
Total, Recorded Investment	300	0
Total, Unpaid Principal Balance	300	0
Total, Related Allowance	0	0
With no related allowance recorded, Average Recorded Investment	200	0
With no related allowance recorded, Interest Recognized	9	0
With an allowance recorded, Average Recorded Investment	0	0
With an allowance recorded, Interest Recognized	0	0
Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	35
With no related allowance recorded, Unpaid Principal Balance	55	61
With an allowance recorded, Recorded Investment	20	0
With an allowance recorded, Unpaid Principal Balance	20	0
With an allowance recorded, Related Allowance	20	0
Total, Recorded Investment	55	42
Total, Unpaid Principal Balance	75	61
Total, Related Allowance	20	0
With no related allowance recorded, Average Recorded Investment	39	42
With no related allowance recorded, Interest Recognized	0	0
With an allowance recorded, Average Recorded Investment	23	0
With an allowance recorded, Interest Recognized	1	0
Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	2,306
With no related allowance recorded, Unpaid Principal Balance	2,312	0
With an allowance recorded, Recorded Investment	0	0
With an allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Related Allowance	0	0
Total, Recorded Investment	2,306	0
Total, Unpaid Principal Balance	2,312	0
Total, Related Allowance	0	0
With no related allowance recorded, Average Recorded Investment	2,365	0
With no related allowance recorded, Interest Recognized	125	0
With an allowance recorded, Average Recorded Investment	0	0
With an allowance recorded, Interest Recognized	0	0
Residential Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
With an allowance recorded, Recorded Investment	0	0
With an allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Related Allowance	0	0
Total, Recorded Investment	4,652	709
Total, Unpaid Principal Balance	4,683	779
Total, Related Allowance	0	0
With no related allowance recorded, Average Recorded Investment	4,772	759
With no related allowance recorded, Interest Recognized	159	20
With an allowance recorded, Average Recorded Investment	0	0
With an allowance recorded, Interest Recognized	0	0
Consumer Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Recorded Investment	0	0
With an allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Related Allowance	0	0
Total, Recorded Investment	0	0
Total, Unpaid Principal Balance	0	0
Total, Related Allowance	0	0
With no related allowance recorded, Average Recorded Investment	0	0
With no related allowance recorded, Interest Recognized	0	0
With an allowance recorded, Average Recorded Investment	0	0
With an allowance recorded, Interest Recognized	0	0
Municipal Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Recorded Investment	0	0
With an allowance recorded, Unpaid Principal Balance	0	0
With an allowance recorded, Related Allowance	0	0
Total, Recorded Investment	0	0
Total, Unpaid Principal Balance	0	0
Total, Related Allowance	0	0
With no related allowance recorded, Average Recorded Investment	0	0
With no related allowance recorded, Interest Recognized	0	0
With an allowance recorded, Average Recorded Investment	0	0
With an allowance recorded, Interest Recognized	$ 0	$ 0