Income Taxes - Components of Provision for (Benefit from) Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current tax provision (benefit):
Foreign	$ 38	$ 59	$ 85
Total current tax provision (benefit)	38	59	85
Deferred tax provision (benefit):
Foreign	(41)	83	(245)
Total deferred tax provision (benefit)	(41)	83	(245)
Total provision for (benefit from) income taxes	$ (3)	$ 142	$ (160)