CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Ordinary shares	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit	Total
Beginning balance at Dec. 31, 2020	$ 2,711	$ 1,016,018	$ 9,907	$ (784,731)	$ 243,905
Beginning balance (in shares) at Dec. 31, 2020	44,777,799
Increase (decrease) in shareholders' equity
Income / Loss for the period				357,912	357,912
Other comprehensive loss			(14,502)		(14,502)
Issuance of ordinary shares	$ 55	29,509			29,564
Issuance of ordinary shares (in shares)	921,730
Income tax benefit of past share issuance cost		2,977			2,977
Exercise of share options	$ 5	906			911
Exercise of share options (in shares)	71,976
Restricted share units distributed during the period	$ 17	(17)
Restricted share units distributed during the period (in shares)	277,571
Share-based compensation expense		12,792			12,792
Issuance of ordinary shares relating to employee stock purchase plan		49			49
Issuance of ordinary shares relating to employee stock purchase plan (in shares)	1,174
Ending balance at Jun. 30, 2021	$ 2,788	1,062,234	(4,595)	(426,819)	633,608
Ending balance (in shares) at Jun. 30, 2021	46,050,250
Beginning balance at Mar. 31, 2021	$ 2,780	1,049,850	2,347	(826,287)	228,690
Beginning balance (in shares) at Mar. 31, 2021	45,924,729
Increase (decrease) in shareholders' equity
Income / Loss for the period				399,468	399,468
Other comprehensive loss			(6,942)		(6,942)
Issuance of ordinary shares	$ 3	1,862			1,865
Issuance of ordinary shares (in shares)	61,845
Income tax benefit of past share issuance cost		2,977			2,977
Exercise of share options	$ 4	515			519
Exercise of share options (in shares)	55,194
Restricted share units distributed during the period	$ 1	(1)
Restricted share units distributed during the period (in shares)	8,482
Share-based compensation expense		7,031			7,031
Ending balance at Jun. 30, 2021	$ 2,788	1,062,234	(4,595)	(426,819)	633,608
Ending balance (in shares) at Jun. 30, 2021	46,050,250
Beginning balance at Dec. 31, 2021	$ 2,802	1,076,972	(28,856)	(455,142)	$ 595,776
Beginning balance (in shares) at Dec. 31, 2021	46,298,635				46,298,635
Increase (decrease) in shareholders' equity
Income / Loss for the period				(85,739)	$ (85,739)
Other comprehensive loss			(38,774)		(38,774)
Exercise of share options	$ 4	449			453
Exercise of share options (in shares)	72,594
Restricted share units distributed during the period	$ 17	(17)
Restricted share units distributed during the period (in shares)	307,464
Share-based compensation expense		14,682			14,682
Issuance of ordinary shares relating to employee stock purchase plan		90			90
Issuance of ordinary shares relating to employee stock purchase plan (in shares)	5,890
Ending balance at Jun. 30, 2022	$ 2,823	1,092,176	(67,630)	(540,881)	$ 486,488
Ending balance (in shares) at Jun. 30, 2022	46,684,583				46,684,583
Beginning balance at Mar. 31, 2022	$ 2,821	1,084,306	(39,306)	(501,820)	$ 546,001
Beginning balance (in shares) at Mar. 31, 2022	46,641,448
Increase (decrease) in shareholders' equity
Income / Loss for the period				(39,061)	(39,061)
Other comprehensive loss			(28,324)		(28,324)
Exercise of share options		29			29
Exercise of share options (in shares)	4,470
Restricted share units distributed during the period	$ 2	(2)
Restricted share units distributed during the period (in shares)	36,333
Share-based compensation expense		7,813			7,813
Issuance of ordinary shares relating to employee stock purchase plan		30			30
Issuance of ordinary shares relating to employee stock purchase plan (in shares)	2,332
Ending balance at Jun. 30, 2022	$ 2,823	$ 1,092,176	$ (67,630)	$ (540,881)	$ 486,488
Ending balance (in shares) at Jun. 30, 2022	46,684,583				46,684,583