Provision for Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Expected tax expense, at the U.S. federal statutory income tax rate of 21%	$ 1,138	$ 513	$ 3,707	$ 2,270
State income taxes	170	90	570	384
FDII benefit	(33)	(7)	(73)	(39)
Other, net	13	14	10	25
Total provision for income taxes	$ 1,288	$ 610	$ 4,214	$ 2,640