Net Loss per Share - Summary of Basic and Diluted Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Loss	$ (7,986)	$ (11,420)	$ (32,908)	$ (29,733)
Deemed dividend from exchange of convertible preferred stock			(9,050)
Net loss attributable to common stockholders	$ (7,986)	$ (11,420)	$ (41,958)	$ (29,733)
Weighted average common shares outstanding, basic and diluted	20,677,392	1,745,404	8,211,003	1,638,579
Net loss per share, basic and diluted	$ (0.39)	$ (6.54)	$ (5.11)	$ (18.15)