Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net loss, basic and diluted	$ (38,205)	$ (22,903)	$ (15,805)	$ (20,722)	$ (61,108)	$ (36,527)
Denominator:
Weighted-average shares outstanding, basic and diluted	98,541		63,713		92,912	63,140
Net loss per share, basic and diluted:	$ (0.39)		$ (0.25)		$ (0.66)	$ (0.58)