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, 2020		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				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, 2021	480,082,966	489,177,550
Beginning balance at Dec. 31, 2021	$ 148,005	$ 31,855	385,070	(603)	(4,601)	(263,716)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(24,837)					(24,837)
Issuance of common shares under at-the-market sales agreement (in shares)		80,696
Issuance of common shares under at-the-market sales agreement	67	$ 5	62
Restricted share units vested				186		(186)
Issuance of ordinary shares to treasury (in shares)		4,800,000
Issuance of ordinary shares to treasury		$ 322		(322)
Common shares withheld for taxes on vested stock awards	(793)		(793)
Equity settled share-based compensation reclassified as cash-settled	118		118
Share-based compensation	$ 3,747		3,747
Ending balance (in shares) at Mar. 31, 2022	482,944,390	494,058,246
Ending balance at Mar. 31, 2022	$ 126,307	$ 32,182	$ 388,204	$ (739)	$ (4,601)	$ (288,739)