Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income(Loss)	Total Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2018		16,452,976
Beginning balance at Dec. 31, 2018	$ 32,170	$ 165	$ 166,628	$ (6,571)	$ (128,052)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issue of common stock, net of offering costs (in shares)		15,625,000
Issue of common stock, net of offering costs	24,501	$ 156	24,345
Issuance on common stock from exercise of share options (in shares)		20,975
Issuance on common stock from exercise of stock options	2		2
Stock-based compensation	848		848
Unrealized gain (loss) on foreign currency translation adjustments	(1,299)			(1,299)
Net loss	(20,045)				(20,045)
Ending balance (in shares) at Sep. 30, 2019		32,098,951
Ending balance at Sep. 30, 2019	36,177	$ 321	191,823	(7,870)	(148,097)
Beginning balance (in shares) at Jun. 30, 2019		32,098,951
Beginning balance at Jun. 30, 2019	43,564	$ 321	191,579	(6,615)	(141,721)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	244		244
Unrealized gain (loss) on foreign currency translation adjustments	(1,255)			(1,255)
Net loss	(6,376)				(6,376)
Ending balance (in shares) at Sep. 30, 2019		32,098,951
Ending balance at Sep. 30, 2019	$ 36,177	$ 321	191,823	(7,870)	(148,097)
Beginning balance (in shares) at Dec. 31, 2019	67,178,054	67,178,054
Beginning balance at Dec. 31, 2019	$ 77,237	$ 672	241,204	(4,720)	(159,919)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Fractional shares issued from reverse stock split (in shares)		3
Issuance on common stock from exercise of share options (in shares)		53,846
Issuance on common stock from exercise of stock options	3		3
Stock-based compensation	1,188		1,188
Unrealized gain (loss) on foreign currency translation adjustments	(2,312)			(2,312)
Net loss	$ (39,255)				(39,255)
Ending balance (in shares) at Sep. 30, 2020	67,231,903	67,231,903
Ending balance at Sep. 30, 2020	$ 36,861	$ 672	242,395	(7,032)	(199,174)
Beginning balance (in shares) at Jun. 30, 2020		67,231,900
Beginning balance at Jun. 30, 2020	51,946	$ 672	242,034	(9,287)	(181,473)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Fractional shares issued from reverse stock split (in shares)		3
Stock-based compensation	361		361
Unrealized gain (loss) on foreign currency translation adjustments	2,255			2,255
Net loss	$ (17,701)				(17,701)
Ending balance (in shares) at Sep. 30, 2020	67,231,903	67,231,903
Ending balance at Sep. 30, 2020	$ 36,861	$ 672	$ 242,395	$ (7,032)	$ (199,174)