Net Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net loss	$ (8,508)	$ (15,589)	$ (21,169)	$ (32,689)
Denominator:
Weighted-average shares used to compute basic and diluted net loss per share	115,982	109,245	114,970	108,292
Basic and diluted net loss per share	$ (0.07)	$ (0.14)	$ (0.18)	$ (0.30)