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, 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 gain (loss) on marketable securities, net of tax provision	(4,511)			(4,511)
Net income (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)
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)
Unrealized gain (loss) on marketable securities, net of tax provision	(6,765)
Net income (loss)	(66,039)
BALANCE at Jun. 30, 2022	1,082,324	$ 1,688	2,858,422	(10,488)	(1,607,057)	$ (160,241)
BALANCE (in shares) at Jun. 30, 2022		168,782,701				(4,549,997)
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)
Issuance of ordinary shares under employee stock plans	16,197	$ 11	16,186
Issuance of ordinary shares under employee stock plans (in shares)		1,038,859
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards	(514)					$ (514)
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards (in shares)						(18,566)
Share-based compensation	23,641		23,641
Unrealized gain (loss) on marketable securities, net of tax provision	(2,254)			(2,254)
Net income (loss)	(30,136)				(30,136)
BALANCE at Jun. 30, 2022	1,082,324	$ 1,688	2,858,422	(10,488)	(1,607,057)	$ (160,241)
BALANCE (in shares) at Jun. 30, 2022		168,782,701				(4,549,997)
BALANCE at Dec. 31, 2022	1,043,753	$ 1,690	2,913,099	(10,889)	(1,699,285)	$ (160,862)
BALANCE (in shares) at Dec. 31, 2022		168,951,193				(4,574,184)
Issuance of ordinary shares under employee stock plans	2,874	$ 25	2,849
Issuance of ordinary shares under employee stock plans (in shares)		2,567,603
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards	(24,744)					$ (24,744)
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards (in shares)						(885,652)
Share-based compensation	22,778		22,778
Unrealized gain (loss) on marketable securities, net of tax provision	2,760			2,760
Net income (loss)	(41,845)				(41,845)
BALANCE at Mar. 31, 2023	1,005,576	$ 1,715	2,938,726	(8,129)	(1,741,130)	$ (185,606)
BALANCE (in shares) at Mar. 31, 2023		171,518,796				(5,459,836)
BALANCE at Dec. 31, 2022	1,043,753	$ 1,690	2,913,099	(10,889)	(1,699,285)	$ (160,862)
BALANCE (in shares) at Dec. 31, 2022		168,951,193				(4,574,184)
Unrealized gain (loss) on marketable securities, net of tax provision	3,452
Net income (loss)	195,220
BALANCE at Jun. 30, 2023	1,280,437	$ 1,720	2,976,365	(7,437)	(1,504,065)	$ (186,146)
BALANCE (in shares) at Jun. 30, 2023		171,975,901				(5,477,613)
BALANCE at Mar. 31, 2023	1,005,576	$ 1,715	2,938,726	(8,129)	(1,741,130)	$ (185,606)
BALANCE (in shares) at Mar. 31, 2023		171,518,796				(5,459,836)
Issuance of ordinary shares under employee stock plans	9,126	$ 5	9,121
Issuance of ordinary shares under employee stock plans (in shares)		457,105
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards	(540)					$ (540)
Receipt of Alkermes' shares for the exercise of stock options or to satisfy minimum tax withholding obligations related to share-based awards (in shares)						(17,777)
Share-based compensation	28,518		28,518
Unrealized gain (loss) on marketable securities, net of tax provision	692			692
Net income (loss)	237,065				237,065
BALANCE at Jun. 30, 2023	$ 1,280,437	$ 1,720	$ 2,976,365	$ (7,437)	$ (1,504,065)	$ (186,146)
BALANCE (in shares) at Jun. 30, 2023		171,975,901				(5,477,613)