Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance (in shares) at Dec. 31, 2019		33,156,000
Beginning Balance at Dec. 31, 2019	$ 9,756	$ 33	$ 132,214	$ (122,492)	$ 1
Increase (Decrease) in Stockholders' Equity
Vesting of restricted stock units (in shares)		2,183,000
Vesting of restricted stock units	2	$ 2
Stock-based compensation	6,166		6,166
Sales of common stock, net of offering costs (in shares)		23,776,000
Sales of common stock, net of offering costs	37,447	$ 24	37,423
Exercises of warrants (in shares)		7,000
Exercises of stock options (in shares)		6,000
Exercise of stock options	10		10
Net loss	(28,414)			(28,414)
Foreign currency translation adjustment	$ 86				86
Ending Balance (in shares) at Dec. 31, 2020	59,128,356	59,128,000
Ending Balance at Dec. 31, 2020	$ 25,053	$ 59	175,813	(150,906)	87
Increase (Decrease) in Stockholders' Equity
Vesting of restricted stock units (in shares)		2,174,000
Vesting of restricted stock units	1	$ 1
Stock-based compensation	7,930		7,930
Sales of common stock, net of offering costs (in shares)		5,593,000
Sales of common stock, net of offering costs	17,986	$ 7	17,979
Exercises of stock options (in shares)		105,000
Exercise of stock options	292		292
Net loss	(35,970)			(35,970)
Foreign currency translation adjustment	$ (36)				(36)
Ending Balance (in shares) at Dec. 31, 2021	66,999,853	67,000,000
Ending Balance at Dec. 31, 2021	$ 15,256	$ 67	$ 202,014	$ (186,876)	$ 51