Income Taxes - Income Tax Provision Attributable to Income from Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Expected provision using statutory federal income tax rate	$ 2,815	$ 2,750	$ 2,713
Effect of bond and loan tax-exempt income	(121)	(117)	(124)
Bank owned life insurance income	(130)	(110)	(94)
Other	3	5	9
Total income tax provision	$ 2,567	$ 2,528	$ 2,504