Net Loss per Share of Common Stock - Summary of Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net loss	$ (5,041)	$ (10,796)	$ (3,044)	$ (4,704)	$ (15,837)	$ (7,748)
Basic and diluted net loss per common share	$ (0.32)		$ (0.27)		$ (1.02)	$ (0.69)
Weighted-average common shares used to compute basic and diluted net loss per share	15,902		11,280		15,457	11,277