Significant Accounting Policies - Calculation of Net Loss and Number of Shares Used to Compute Basic and Diluted Net Loss per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Loss Earnings Per Share [Line Items]
Net loss-basic and diluted	$ (5,140)	$ (13,151)	$ (106,659)	$ (6,969)
Weighted average shares outstanding-basic	404,614	396,618	399,944	395,681
Weighted average shares outstanding-diluted	404,614	396,618	399,944	395,681
Net loss per share-basic	$ (0.01)	$ (0.03)	$ (0.27)	$ (0.02)
Net loss per share-diluted	$ (0.01)	$ (0.03)	$ (0.27)	$ (0.02)