Net Loss Per Common Share - Schedule of Net Loss Per Common Share, Basic and Diluted (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
Numerator:
Net loss	$ (12,669)	$ (32,011)	$ (20,957)	$ (19,615)	$ (11,312)	$ (18,693)	$ (65,637)	$ (49,620)
Denominator [Abstract]
Weighted-average shares used to compute basic net loss per share (in shares)	156,647,259			20,303,631			123,175,390	15,753,057
Weighted-average shares used to compute diluted net loss per share (in shares)	156,647,259			20,303,631			123,175,390	15,753,057
Net loss per common share, basic (in dollars per share)	$ (0.08)			$ (0.97)			$ (0.53)	$ (3.15)
Net loss per common share, diluted (in dollars per share)	$ (0.08)			$ (0.97)			$ (0.53)	$ (3.15)