CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIENCY) - USD ($) $ in Thousands	Common Stock Common Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Common Stock	Additional Paid-in Capital Common Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Common Stock Offering under the Lincoln Park Capital Registered Offering Purchase Agreement	Total
Balance at the beginning of the period at Dec. 31, 2017		$ 12		$ 141,770	$ (268)	$ (130,397)		$ 11,117
Balance at the beginning of the period (in shares) at Dec. 31, 2017		12,354,014
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of issuance costs		$ 3		14,793				14,796
Issuance of common stock (in shares)		2,146,667
Issuance of common stock upon exercise of warrants				2,347				2,347
Issuance of common stock upon exercise of warrants (in shares)		200,000
Issuance of common stock upon exercise of stock options				14				$ 14
Exercised (in shares)		2,478						2,478
Foreign currency translation adjustment					570			$ 570
Stock-based compensation				3,469				3,469
Net loss						(23,138)		(23,138)
Balance at the end of the period at Dec. 31, 2018		$ 15		162,393	302	(153,535)		9,175
Balance at the end of the period (in shares) at Dec. 31, 2018		14,703,159
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of issuance costs	$ 1	$ 7	$ 999	12,115			$ 1,000	12,122
Issuance of common stock (in shares)	571,429	7,557,142
Issuance of common stock through ATM sales		$ 1		1,922				1,923
Issuance of common stock through ATM sales (in shares)		1,033,147
ATM issuance costs				(13)				(13)
Commitment purchase agreement (in shares)		330,000
Lincoln Park issuance costs				(10)				(10)
Foreign currency translation adjustment					(226)			(226)
Reclassification of 2017 warrants from liability to equity				11,822		(8,374)		3,448
Dividend attributable to down round feature of warrants				359		(359)		(359)
Stock-based compensation				3,732				3,732
Net loss						(32,900)		(32,900)
Balance at the end of the period at Dec. 31, 2019		$ 24		$ 193,319	$ 76	$ (195,168)		$ (1,749)
Balance at the end of the period (in shares) at Dec. 31, 2019		24,194,877