Net Loss per Share - Computation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net loss	$ (20,080)	$ (14,103)
Denominator:
Weighted-average shares used to compute net loss per common share, basic and diluted	27,703,918	24,297,576
Net loss per shares, basic and diluted	$ (0.72)	$ (0.58)