Net Loss Per Share Attributable to Common Stockholders - Schedule of Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator
Net loss	$ (8,417)	$ (8,390)
Net loss attributable to common stockholders	$ (8,417)	$ (8,390)
Denominator
Basic	89,862	88,295
Diluted	89,862	88,295
Net loss attributable to common stockholders per share
Basic	$ (0.09)	$ (0.10)
Diluted	$ (0.09)	$ (0.10)