Premises and Equipment - Summary of Net Lease Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Net Lease Cost:
Operating lease cost	$ 87	$ 85
Net lease cost	$ 87	$ 85
Selected other operating lease information:
Weighted average remaining lease terms (years)	3 years 1 month 6 days	1 year 2 months 12 days
Weighted average discount rate	1.70%	1.79%