Condensed Statements Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Total
Beginning balance (in shares) at Dec. 31, 2019	31,255,267
Beginning balance at Dec. 31, 2019	$ 31	$ 263,384	$ (191,526)	$ 2	$ 71,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	140,370
Exercise of stock options		274			274
Stock-based compensation		1,293			1,293
Net loss			(9,941)		(9,941)
Unrealized gain (loss) on investments, net				440	440
Ending balance (in shares) at Mar. 31, 2020	31,395,637
Ending balance at Mar. 31, 2020	$ 31	264,951	(201,467)	442	63,957
Beginning balance (in shares) at Dec. 31, 2020	34,249,649
Beginning balance at Dec. 31, 2020	$ 34	346,318	(238,891)	39	$ 107,500
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	163,151				163,151
Exercise of stock options		848			$ 848
Issuance of common stock upon release of restricted stock units (in shares)	25,490
Stock-based compensation		3,533			3,533
Net loss			(10,694)		(10,694)
Unrealized gain (loss) on investments, net				(33)	(33)
Ending balance (in shares) at Mar. 31, 2021	34,438,290
Ending balance at Mar. 31, 2021	$ 34	$ 350,699	$ (249,585)	$ 6	$ 101,154