Unaudited Condensed Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Cumulative Translation Adjustments
Beginning balance (in shares) at Dec. 31, 2020		61,881
Beginning balance at Dec. 31, 2020	$ 16,424	$ 62	$ 158,190	$ (141,825)	$ (3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering costs (in shares)		3,846
Issuance of common stock, net of offering costs	24,871	$ 4	24,867
Issuance of common stock resulting from the exercise of stock options (in shares)		1,975
Issuance of common stock resulting from the exercise of stock options	8,633	$ 2	8,631
Share-based compensation	1,284		1,284
Translation adjustment	1				1
Net loss	(7,381)			(7,381)
Ending balance (in shares) at Mar. 31, 2021		67,702
Ending balance at Mar. 31, 2021	43,832	$ 68	192,972	(149,206)	(2)
Beginning balance (in shares) at Dec. 31, 2021		68,126
Beginning balance at Dec. 31, 2021	31,727	$ 68	200,614	(168,953)	(2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		23
Share-based compensation	1,888		1,888
Translation adjustment	2				2
Net loss	(7,740)			(7,740)
Ending balance (in shares) at Mar. 31, 2022		68,149
Ending balance at Mar. 31, 2022	$ 25,877	$ 68	$ 202,502	$ (176,693)	$ 0