Unaudited Condensed Consolidated Statements 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)		4,059
Issuance of common stock, net of offering costs	26,740	$ 4	26,736
Issuance of common stock resulting from the exercise of stock options (in shares)		2,069
Issuance of common stock resulting from the exercise of stock options	9,024	$ 2	9,022
Share-based compensation	2,900		2,900
Translation adjustment	1				1
Net loss	(12,947)			(12,947)
Ending balance (in shares) at Jun. 30, 2021		68,009
Ending balance at Jun. 30, 2021	42,142	$ 68	196,848	(154,772)	(2)
Beginning balance (in shares) at Mar. 31, 2021		67,702
Beginning balance at Mar. 31, 2021	43,832	$ 68	192,972	(149,206)	(2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of offering costs (in shares)		213
Issuance of common stock, net of offering costs	1,869		1,869
Issuance of common stock resulting from the exercise of stock options (in shares)		94
Issuance of common stock resulting from the exercise of stock options	391		391
Share-based compensation	1,616		1,616
Net loss	(5,566)			(5,566)
Ending balance (in shares) at Jun. 30, 2021		68,009
Ending balance at Jun. 30, 2021	42,142	$ 68	196,848	(154,772)	(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)		29
Share-based compensation	3,184		3,184
Translation adjustment	4				4
Net loss	(14,137)			(14,137)
Ending balance (in shares) at Jun. 30, 2022		68,155
Ending balance at Jun. 30, 2022	20,778	$ 68	203,798	(183,090)	2
Beginning balance (in shares) at Mar. 31, 2022		68,149
Beginning balance at Mar. 31, 2022	25,877	$ 68	202,502	(176,693)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		6
Share-based compensation	1,296		1,296
Translation adjustment	2				2
Net loss	(6,397)			(6,397)
Ending balance (in shares) at Jun. 30, 2022		68,155
Ending balance at Jun. 30, 2022	$ 20,778	$ 68	$ 203,798	$ (183,090)	$ 2