Net Loss Per Share - Summary 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, 2019	Mar. 31, 2018
Numerator:
Net loss allocable to common stockholders	$ (9,732)	$ (6,634)
Denominator:
Weighted-average shares used in computing net loss per share, basic and diluted	110,877	99,488
Net loss per share, basic and diluted	$ (0.09)	$ (0.07)

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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