Income Taxes - Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Beginning balance	$ 314	$ 264	$ 43
Increases based on tax positions related to prior years			109
Decreases based on tax positions related to prior years	(54)	(103)
Decreases due to ownership change	(207)
Increases based on tax positions in current year	568	153	112
Ending balance	$ 621	$ 314	$ 264