Net Income (Loss) Per Share - Schedule of Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net loss attributable to common shareholders	$ (28,849)	$ (14,053)	$ (51,673)	$ (25,786)
Denominator:
Weighted average common shares outstanding	38,542,591	36,834,135	38,435,846	36,801,357
Weighted average unvested common shares subject to repurchase	(251,177)	(524,395)	(285,326)	(558,543)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	38,291,414	36,309,740	38,150,520	36,242,814
Net loss per share attributable to common stockholders, basic and diluted	$ (0.75)	$ (0.39)	$ (1.35)	$ (0.71)