CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total	Ordinary Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Treasury Stock
BALANCE at Dec. 31, 2020	$ 1,066,982	$ 1,620	$ 2,685,647	$ (1,349)	$ (1,492,849)	$ (126,087)
BALANCE (in shares) at Dec. 31, 2020		162,269,220				(3,108,079)
Issuance of ordinary shares under employee stock plans	2,053	$ 18	2,035
Issuance of ordinary shares under employee stock plans (in shares)		1,566,685
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards	(10,413)					$ (10,413)
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards (in shares)						(529,817)
Share-based compensation	15,552		15,552
Unrealized loss on marketable securities, net of tax (benefit)	(601)			(601)
Net loss	(22,418)				(22,418)
BALANCE at Mar. 31, 2021	1,051,155	$ 1,638	2,703,234	(1,950)	(1,515,267)	$ (136,500)
BALANCE (in shares) at Mar. 31, 2021		163,835,905				(3,637,896)
BALANCE at Dec. 31, 2021	1,112,584	$ 1,658	2,798,325	(3,723)	(1,541,018)	$ (142,658)
BALANCE (in shares) at Dec. 31, 2021		165,790,549				(3,853,222)
Issuance of ordinary shares under employee stock plans	1,795	$ 19	1,776
Issuance of ordinary shares under employee stock plans (in shares)		1,953,293
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards	(17,069)					$ (17,069)
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards (in shares)						(678,209)
Share-based compensation	18,494		18,494
Unrealized loss on marketable securities, net of tax (benefit)	(4,511)			(4,511)
Net loss	(35,903)				(35,903)
BALANCE at Mar. 31, 2022	$ 1,075,390	$ 1,677	$ 2,818,595	$ (8,234)	$ (1,576,921)	$ (159,727)
BALANCE (in shares) at Mar. 31, 2022		167,743,842				(4,531,431)