CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income [Member]
Balance at Dec. 31, 2020	$ 18,541	$ 18	$ 528,362	$ (510,680)	$ 841
Balance, shares at Dec. 31, 2020		18,139,981
Net loss	(12,280)			(12,280)
Issuance of stock, net of issue costs	108,403	$ 11	108,392
Issuance of stock, net of issue costs, shares		10,513,538
Employee stock purchase plan	173		173
Employee stock purchase plan, shares		27,713
Exercise of stock options	10		10
Exercise of stock options, shares		827
Vesting of stock units	(128)		(128)
Vesting of stock units, shares		59,416
Stock-based compensation	988		988
Balance at Mar. 31, 2021	115,707	$ 29	637,797	(522,960)	841
Balance, shares at Mar. 31, 2021		28,741,475
Balance at Dec. 31, 2021	$ 184,380	$ 34	752,602	(569,097)	841
Balance, shares at Dec. 31, 2021	33,905,826	33,905,826
Net loss	$ (20,976)			(20,976)
Other comprehensive loss	(53)				(53)
Employee stock purchase plan	201		201
Employee stock purchase plan, shares		28,504
Exercise of stock options	40		40
Exercise of stock options, shares		4,223
Vesting of stock units	(250)		(250)
Vesting of stock units, shares		108,575
Stock-based compensation	3,477		3,477
Balance at Mar. 31, 2022	$ 166,819	$ 34	$ 756,070	$ (590,073)	$ 788
Balance, shares at Mar. 31, 2022	34,047,128	34,047,128