Net Loss Per Share - Computation of Loss Per Share (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	$ (14,159)	$ (5,369)	$ (34,240)	$ (13,199)
Denominator:
Weighted-average common shares outstanding, basic and diluted (in shares)	25,032,996	22,619,805	25,057,715	21,531,216
Net loss per common share, basic and diluted (in dollars per share)	$ (0.57)	$ (0.24)	$ (1.37)	$ (0.61)