Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net loss attributable to common stockholders	$ (36,678)	$ (28,138)	$ (9,299)
Weighted-average shares outstanding	7,319,977	2,148,317	2,049,680
Less: weighted-average unvested restricted shares and shares subject to repurchase		(9,344)	(102,704)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	7,319,977	2,138,973	1,946,976
Net loss per share attributable to common stockholders, basic and diluted	$ (5.01)	$ (13.15)	$ (4.78)