Net Loss Per Share - Computation of Basic and Diluted Net Loss and Weighted Average Number of Shares Used in Computing Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net loss	$ (7,321)	$ (8,977)	$ (67,789)	$ (19,560)
Net loss allocated to stockholders of the Company	$ (7,243)	$ (8,640)	$ (70,585)	$ (19,823)
Weighted-average number of shares used in per share calculation:
Weighted-average shares of common stock outstanding used in computing net loss per share, basic and diluted	40,466	4,884	34,553	4,812
Net loss per share:
Basic and diluted	$ (0.18)	$ (1.77)	$ (2.04)	$ (4.12)