Net Loss Per Share of Common Stock - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net loss	$ (15,872)	$ (13,981)	$ (12,242)	$ (9,474)	$ (12,472)	$ (12,772)	$ (42,095)	$ (34,718)
Weighted-average number of common shares used to compute basic net loss per share (in shares)	33,340,093			28,713,418			33,005,904	28,155,561
Weighted-average number of common shares used to compute diluted net loss per share (in shares)	33,340,093			28,713,418			33,005,904	28,155,561
Net loss per share, basic (in usd per share)	$ (0.48)			$ (0.33)			$ (1.28)	$ (1.23)
Net loss per share, diluted (in usd per share)	$ (0.48)			$ (0.33)			$ (1.28)	$ (1.23)