Condensed Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity/Deficit (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Profit certificates	Additional paid-in capital	Accumulated other comprehensive income (loss)	Retained earnings/(accumulated deficit)	Series A preferred stock	Series B preferred stock
Beginning balance at Dec. 31, 2018	$ (10,678)	$ 87	$ 11		$ (11)	$ (10,765)
Temporary equity, beginning balance (in shares) at Dec. 31, 2018							6,167,726	10,900,376
Temporary equity, beginning balance at Dec. 31, 2018							$ 5,353	$ 20,378
Beginning balance (in shares) at Dec. 31, 2018		185,716	7,022
Accretion of Series B and B-2 Preferred Stock to redemption value	(697)			$ (205)		(492)		$ 697
Stock-based compensation	205			205
Currency translation adjustment	(267)				(267)
Net loss	(4,402)					(4,402)
Ending balance at Mar. 31, 2019	(15,839)	$ 87	$ 11		(278)	(15,659)
Temporary equity, ending balance (in shares) at Mar. 31, 2019							6,167,726	10,900,376
Temporary equity, ending balance at Mar. 31, 2019							$ 5,353	$ 21,075
Ending balance (in shares) at Mar. 31, 2019		185,716	7,022
Beginning balance at Dec. 31, 2018	(10,678)	$ 87	$ 11		(11)	(10,765)
Temporary equity, beginning balance (in shares) at Dec. 31, 2018							6,167,726	10,900,376
Temporary equity, beginning balance at Dec. 31, 2018							$ 5,353	$ 20,378
Beginning balance (in shares) at Dec. 31, 2018		185,716	7,022
Net loss	(10,157)
Ending balance at Jun. 30, 2019	(21,675)	$ 87	$ 113		251	(22,126)
Temporary equity, ending balance (in shares) at Jun. 30, 2019							6,167,726	20,942,781
Temporary equity, ending balance at Jun. 30, 2019							$ 5,353	$ 44,362
Ending balance (in shares) at Jun. 30, 2019		185,716	70,832
Beginning balance at Mar. 31, 2019	(15,839)	$ 87	$ 11		(278)	(15,659)
Temporary equity, beginning balance (in shares) at Mar. 31, 2019							6,167,726	10,900,376
Temporary equity, beginning balance at Mar. 31, 2019							$ 5,353	$ 21,075
Beginning balance (in shares) at Mar. 31, 2019		185,716	7,022
Issuance of Preferred Stock								$ 22,372
Issuance of Series B Preferred Stock (in shares)								10,042,405
Accretion of Series B and B-2 Preferred Stock to redemption value	(915)			(203)		(712)		$ 915
Exercise of stock options into common stock/profit certificates	102		$ 102
Exercise of stock options into common stock/profit certificates (in shares)			63,810
Stock-based compensation	203			203
Currency translation adjustment	529				529
Net loss	(5,755)					(5,755)
Ending balance at Jun. 30, 2019	(21,675)	$ 87	$ 113		251	(22,126)
Temporary equity, ending balance (in shares) at Jun. 30, 2019							6,167,726	20,942,781
Temporary equity, ending balance at Jun. 30, 2019							$ 5,353	$ 44,362
Ending balance (in shares) at Jun. 30, 2019		185,716	70,832
Beginning balance at Dec. 31, 2019	(36,088)	$ 1			(224)	(35,865)
Temporary equity, beginning balance (in shares) at Dec. 31, 2019							6,167,726	20,942,781
Temporary equity, beginning balance at Dec. 31, 2019							$ 5,353	$ 46,404
Beginning balance (in shares) at Dec. 31, 2019		256,548
Issuance of Preferred Stock								$ 125,026
Issuance of Series B Preferred Stock (in shares)								44,453,477
Settlement of preferred stock tranche right	4,135			4,135
Accretion of Series B and B-2 Preferred Stock to redemption value	(1,195)			(1,195)				$ 1,195
Stock-based compensation	186			186
Currency translation adjustment	(317)				(317)
Net loss	(5,247)					(5,247)
Ending balance at Mar. 31, 2020	(38,526)	$ 1		3,126	(541)	(41,112)
Temporary equity, ending balance (in shares) at Mar. 31, 2020							6,167,726	65,396,258
Temporary equity, ending balance at Mar. 31, 2020							$ 5,353	$ 172,625
Ending balance (in shares) at Mar. 31, 2020		256,548
Beginning balance at Dec. 31, 2019	(36,088)	$ 1			(224)	(35,865)
Temporary equity, beginning balance (in shares) at Dec. 31, 2019							6,167,726	20,942,781
Temporary equity, beginning balance at Dec. 31, 2019							$ 5,353	$ 46,404
Beginning balance (in shares) at Dec. 31, 2019		256,548
Settlement of preferred stock tranche right	$ 4,135
Exercise of stock options into common stock/profit certificates (in shares)	131,867
Net loss	$ (12,449)
Ending balance at Jun. 30, 2020	(47,922)	$ 1		687	(296)	(48,314)
Temporary equity, ending balance (in shares) at Jun. 30, 2020							6,167,726	65,396,258
Temporary equity, ending balance at Jun. 30, 2020							$ 5,353	$ 175,619
Ending balance (in shares) at Jun. 30, 2020		388,415
Beginning balance at Mar. 31, 2020	(38,526)	$ 1		3,126	(541)	(41,112)
Temporary equity, beginning balance (in shares) at Mar. 31, 2020							6,167,726	65,396,258
Temporary equity, beginning balance at Mar. 31, 2020							$ 5,353	$ 172,625
Beginning balance (in shares) at Mar. 31, 2020		256,548
Accretion of Series B and B-2 Preferred Stock to redemption value	(2,994)			(2,994)				$ 2,994
Exercise of stock options into common stock/profit certificates	205			205
Exercise of stock options into common stock/profit certificates (in shares)		131,867
Stock-based compensation	350			350
Currency translation adjustment	245				245
Net loss	(7,202)					(7,202)
Ending balance at Jun. 30, 2020	$ (47,922)	$ 1		$ 687	$ (296)	$ (48,314)
Temporary equity, ending balance (in shares) at Jun. 30, 2020							6,167,726	65,396,258
Temporary equity, ending balance at Jun. 30, 2020							$ 5,353	$ 175,619
Ending balance (in shares) at Jun. 30, 2020		388,415