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, 2019		59,562
Beginning balance at Dec. 31, 2019	$ 20,445	$ 60	$ 142,285	$ (121,900)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering costs (in shares)		1,225
Issuance of common stock, net of offering costs	4,856	$ 1	4,855
Exercise of stock options (in shares)		1,094
Exercise of stock options	4,115	$ 1	4,114
Share-based compensation	6,936		6,936
Translation adjustment	(3)				(3)
Net loss	(19,925)			(19,925)
Ending balance (in shares) at Dec. 31, 2020		61,881
Ending 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)		4,059
Issuance of common stock, net of offering costs	26,740	$ 4	26,736
Exercise of stock options (in shares)		2,186
Exercise of stock options	9,495	$ 2	9,493
Share-based compensation	6,195		6,195
Translation adjustment	1				1
Net loss	(27,128)			(27,128)
Ending balance (in shares) at Dec. 31, 2021		68,126
Ending balance at Dec. 31, 2021	$ 31,727	$ 68	$ 200,614	$ (168,953)	$ (2)