Net Loss per Share - Summary of Basic and Diluted Net Loss Per Share of Common Stock (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	$ (21,466)	$ (13,420)	$ (44,390)	$ (25,093)
Denominator:
Weighted-average common shares outstanding, basic and diluted (in shares)	50,695,706	48,451,562	50,411,508	48,141,474
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.42)	$ (0.28)	$ (0.88)	$ (0.52)