Income Taxes - Summary of the Income Tax Provision (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Deferred Provision
Income tax (benefit) expense	$ (3)	$ 26	$ (1)	$ 113