CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2019		25,163,803
Stockholders' equity, beginning of period at Dec. 31, 2019	$ 63,008	$ 3	$ 258,121	$ 464	$ (195,580)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock from public offering, net of underwriting discounts, commissions and offering costs (in shares)		3,135,053
Issuance of common stock from public offering, net of underwriting discounts, commissions and offering costs	62,978		62,978
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)		43,334
Issuance of common stock upon exercise of stock options, net of shares withheld	174		174
Issuance of common stock upon vesting of restricted stock units (in shares)		63,938
Issuance of common stock upon vesting of restricted stock units	0
Stock-based compensation	2,622		2,622
Vesting of early exercised stock options	27		27
Foreign currency translation	12			12
Net unrealized gain on marketable securities	221			221
Net loss	(12,772)				(12,772)
Stockholders' equity, end of period (in shares) at Mar. 31, 2020		28,406,128
Stockholders' equity, end of period at Mar. 31, 2020	116,270	$ 3	323,922	697	(208,352)
Stockholders' equity, beginning of period (in shares) at Dec. 31, 2020		32,583,220
Stockholders' equity, beginning of period at Dec. 31, 2020	$ 169,363	$ 3	408,113	524	(239,277)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options, net of shares withheld (in shares)	93,975	93,975
Issuance of common stock upon exercise of stock options, net of shares withheld	$ 601		601
Issuance of common stock upon vesting of restricted stock units (in shares)		131,339
Issuance of common stock upon vesting of restricted stock units	0
Stock-based compensation	4,030		4,030
Vesting of early exercised stock options	9		9
Foreign currency translation	(115)			(115)
Net unrealized gain on marketable securities	21			21
Net loss	(12,242)				(12,242)
Stockholders' equity, end of period (in shares) at Mar. 31, 2021		32,808,534
Stockholders' equity, end of period at Mar. 31, 2021	$ 161,667	$ 3	$ 412,753	$ 430	$ (251,519)