Net Loss Per Common Share - Computation of Basic and Diluted Net Loss per Share Attributable to Common Stock holders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Numerator:
Net loss	$ (9,065)	$ (8,250)
Denominator:
Weighted-average shares used to compute net loss per common share, basic and diluted (in shares)	26,839,870	24,474,308
Net loss per common share, basic and diluted (in USD per share)	$ (0.34)	$ (0.34)