Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Stock subscription not yet issued	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Executive Bonus Agreement	Executive Bonus Agreement Common Stock	Executive Bonus Agreement Additional Paid-In Capital	Series A-2 Convertible Preferred Stock Preferred Stock	Series A-1 Convertible Preferred Stock Preferred Stock	Common Stock Series B	Common Stock Series B Common Stock	Common Stock Series B Additional Paid-In Capital	Public Offering	Public Offering Common Stock	Public Offering Additional Paid-In Capital	April 2020 Equity Issuances	April 2020 Equity Issuances Common Stock	April 2020 Equity Issuances Additional Paid-In Capital	June 2020 Equity Issuances	June 2020 Equity Issuances Common Stock	June 2020 Equity Issuances Additional Paid-In Capital	4SC Settlement Agreement	4SC Settlement Agreement Common Stock	4SC Settlement Agreement Additional Paid-In Capital
Beginning balance (in shares) at Dec. 31, 2018		846,953								299,456	13,541
Beginning balance at Dec. 31, 2018	$ (25,741)	$ 0	$ 56	$ 0	$ (819)	$ (24,978)				$ 34,313	$ 2,879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(4,313)					(4,313)
Foreign exchange translation adjustment	(247)				(247)
Stock subscription not yet issued	20,531			20,531
Ending balance (in shares) at Mar. 31, 2019		846,953								299,456	13,541
Ending balance at Mar. 31, 2019	(9,770)	$ 0	56	20,531	(1,066)	(29,291)				$ 34,313	$ 2,879
Beginning balance (in shares) at Dec. 31, 2018		846,953								299,456	13,541
Beginning balance at Dec. 31, 2018	(25,741)	$ 0	56	0	(819)	(24,978)				$ 34,313	$ 2,879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(19,027)
Ending balance (in shares) at Jun. 30, 2019		9,986,399								0	0
Ending balance at Jun. 30, 2019	69,411	$ 1	114,137	0	(722)	(44,005)				$ 0	$ 0
Beginning balance (in shares) at Mar. 31, 2019		846,953								299,456	13,541
Beginning balance at Mar. 31, 2019	(9,770)	$ 0	56	20,531	(1,066)	(29,291)				$ 34,313	$ 2,879
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(14,714)					(14,714)
Foreign exchange translation adjustment	344				344
Issuance of common stock (in shares)								460,336					2,197,742												120,070
Issuance of common stock							$ 6,014		$ 6,014			$ 29,935		$ 29,935										$ 1,540		$ 1,540
Stock subscription not yet issued	(20,531)			(20,531)
Conversion of Series A Preferred Stock to common stock (in shares)		5,302,029								299,456	13,541
Conversion of Series A Preferred Stock to common stock	37,193	$ 1	37,192							$ (34,313)	$ (2,879)
Exchange of common stock in connection with Transaction (in shares)																									1,059,269
Exchange of common stock in connection with Transaction																								$ 39,400		$ 39,400
Ending balance (in shares) at Jun. 30, 2019		9,986,399								0	0
Ending balance at Jun. 30, 2019	69,411	$ 1	114,137	$ 0	(722)	(44,005)				$ 0	$ 0
Beginning balance (in shares) at Dec. 31, 2019		10,744,806
Beginning balance at Dec. 31, 2019	58,363	$ 1	119,646		(1,373)	(59,911)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(8,487)					(8,487)
Stock-based compensation	353		353
Foreign exchange translation adjustment	(309)				(309)
Issuance of common stock (in shares)																78,745
Issuance of common stock															$ 568		$ 568
Ending balance (in shares) at Mar. 31, 2020		10,823,551
Ending balance at Mar. 31, 2020	50,488	$ 1	120,567		(1,682)	(68,398)
Beginning balance (in shares) at Dec. 31, 2019		10,744,806
Beginning balance at Dec. 31, 2019	58,363	$ 1	119,646		(1,373)	(59,911)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(19,945)
Ending balance (in shares) at Jun. 30, 2020		14,968,340
Ending balance at Jun. 30, 2020	78,685	$ 1	160,148		(1,608)	(79,856)
Beginning balance (in shares) at Mar. 31, 2020		10,823,551
Beginning balance at Mar. 31, 2020	50,488	$ 1	120,567		(1,682)	(68,398)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(11,458)					(11,458)
Stock-based compensation	369		369
Foreign exchange translation adjustment	74				74
Issuance of common stock (in shares)																205,083			1,764,706			2,175,000
Issuance of common stock															$ 2,246		$ 2,246	$ 13,918		$ 13,918	$ 23,048		$ 23,048
Ending balance (in shares) at Jun. 30, 2020		14,968,340
Ending balance at Jun. 30, 2020	$ 78,685	$ 1	$ 160,148		$ (1,608)	$ (79,856)