Basic and Diluted Net Loss Per Share - Computation of Company's Basic and Diluted Net (Loss) Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator
Net loss	$ (20,957)	$ 509	$ (60,721)	$ (12,749)	$ (9,243)	$ (6,358)	$ (81,169)	$ (28,350)
Denominator:
Weighted-average number of shares outstanding for basic and diluted net loss per share (in shares)	89,173			83,283			88,259	82,348
Basic and diluted net loss per share (in dollars per share)	$ (0.24)			$ (0.15)			$ (0.92)	$ (0.34)