Consolidated Statements of Shareholders’ Equity - USD ($) $ in Thousands	Total	Ordinary shares	Additional paid-in capital	Ordinary shares held in treasury	Accumulated other comprehensive loss	Accumulated deficit
Beginning balance (in shares) at Dec. 31, 2019		105,326,638
Beginning balance at Dec. 31, 2019	$ 42,741	$ 7,265	$ 179,535		$ (2,280)	$ (141,779)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,346)					(12,346)
Retranslation of foreign operations	(2,157)				(2,157)
Share options exercised during the period (in shares)		887,080
Share options exercised during the period	52	$ 52
Share-based compensation	1,867		1,867
Ending balance (in shares) at Mar. 31, 2020		106,213,718
Ending balance at Mar. 31, 2020	30,157	$ 7,317	181,402		(4,437)	(154,125)
Beginning balance (in shares) at Dec. 31, 2019		105,326,638
Beginning balance at Dec. 31, 2019	42,741	$ 7,265	179,535		(2,280)	(141,779)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(21,384)
Retranslation of foreign operations	(2,321)
Ending balance (in shares) at Jun. 30, 2020		106,481,006
Ending balance at Jun. 30, 2020	21,853	$ 7,333	182,352		(4,601)	(163,231)
Beginning balance (in shares) at Mar. 31, 2020		106,213,718
Beginning balance at Mar. 31, 2020	30,157	$ 7,317	181,402		(4,437)	(154,125)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(9,038)					(9,038)
Retranslation of foreign operations	(164)				(164)
Share options exercised during the period (in shares)		267,288
Share options exercised during the period	(52)	$ 16				(68)
Share-based compensation	950		950
Ending balance (in shares) at Jun. 30, 2020		106,481,006
Ending balance at Jun. 30, 2020	$ 21,853	$ 7,333	182,352		(4,601)	(163,231)
Beginning balance (in shares) at Dec. 31, 2020	463,304,446	488,304,446
Beginning balance at Dec. 31, 2020	$ 184,854	$ 31,794	366,411	$ (1,700)	(4,601)	(207,050)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(21,290)					(21,290)
Restricted share units vested	0			30		(30)
Share-based compensation	8,850		8,850
Ending balance (in shares) at Mar. 31, 2021		488,304,446
Ending balance at Mar. 31, 2021	$ 172,414	$ 31,794	375,261	(1,670)	(4,601)	(228,370)
Beginning balance (in shares) at Dec. 31, 2020	463,304,446	488,304,446
Beginning balance at Dec. 31, 2020	$ 184,854	$ 31,794	366,411	(1,700)	(4,601)	(207,050)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(43,358)
Retranslation of foreign operations	$ 0
Ending balance (in shares) at Jun. 30, 2021	471,839,302	488,739,150
Ending balance at Jun. 30, 2021	$ 154,397	$ 31,824	379,282	(843)	(4,601)	(251,265)
Beginning balance (in shares) at Mar. 31, 2021		488,304,446
Beginning balance at Mar. 31, 2021	172,414	$ 31,794	375,261	(1,670)	(4,601)	(228,370)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(22,068)					(22,068)
Common shares withheld for taxes on vested stock awards	(3,782)	$ (3,782)
Retranslation of foreign operations	0
Restricted share units vested	0			827		(827)
Share-based compensation	7,450		7,450
Stock issued during period (in shares)		434,704
Stock issued during period	$ 383	$ 30	353
Ending balance (in shares) at Jun. 30, 2021	471,839,302	488,739,150
Ending balance at Jun. 30, 2021	$ 154,397	$ 31,824	$ 379,282	$ (843)	$ (4,601)	$ (251,265)