Income Taxes - Provision For Income taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current tax expense (benefit):
Federal	$ 86	$ (26)
State		(3)
Total current tax expense (benefit)	86	(29)
Deferred tax expense:
Federal	589	19
State	127	1
Valuation allowance	934
Total deferred tax expense	1,650	20
Provision (credit) for income taxes	$ 1,736	$ (9)