Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Numerator [Abstract]
Net loss	$ (20,368)	$ (16,551)	$ (2,334)	$ (16,530)	$ (12,636)	$ (18,412)	$ (20,472)	$ (14,726)	$ (55,783)	$ (66,246)
Denominator [Abstract]
Weighted-average number of common shares - basic and diluted (in shares)									33,651,127	25,356,098
Loss per common share - basic and diluted (in dollars per share)	$ (0.60)	$ (0.49)	$ (0.07)	$ (0.49)	$ (0.48)	$ (0.74)	$ (0.82)	$ (0.59)	$ (1.66)	$ (2.61)
Dilutive Instruments [Abstract]
Anti-dilutive securities excluded from computation of diluted net loss per share (in shares)									1,714,429	1,571,429
Stock Options [Member]
Dilutive Instruments [Abstract]
Anti-dilutive securities excluded from computation of diluted net loss per share (in shares)									3,258,192	2,231,092
Restricted Stock Units Unvested [Member]
Dilutive Instruments [Abstract]
Anti-dilutive securities excluded from computation of diluted net loss per share (in shares)									13,491	73,839