Condensed Consolidated Statements of Changes in Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Restricted Share Units	Ordinary Shares	Ordinary Shares Restricted Share Units	Ordinary Shares Performance Share Units	Treasury Shares	Treasury Shares Restricted Share Units	Additional Paid-In Capital	Additional Paid-In Capital Restricted Share Units	Additional Paid-In Capital Performance Share Units	Retained Earnings (Deficit)	Retained Earnings (Deficit) Restricted Share Units	Retained Earnings (Deficit) Performance Share Units	Accumulated Other Comprehensive Income (Loss)
Beginning balance, ordinary shares (in shares) at Dec. 29, 2023			19.7
Beginning balance at Dec. 29, 2023	$ 1,160.2		$ 0.2			$ 0.0		$ 1,194.6			$ (38.2)			$ 3.6
Beginning balance, treasury stock (in shares) at Dec. 29, 2023						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(65.4)										(65.4)
Other comprehensive income	(4.8)													(4.8)
Share-based compensation	1.9							1.9
Ending balance, ordinary shares (in shares) at Mar. 29, 2024			19.7
Ending balance at Mar. 29, 2024	1,091.9		$ 0.2			$ 0.0		1,196.5			(103.6)			(1.2)
Ending balance, treasury stock (in shares) at Mar. 29, 2024						0.0
Beginning balance, ordinary shares (in shares) at Dec. 29, 2023			19.7
Beginning balance at Dec. 29, 2023	1,160.2		$ 0.2			$ 0.0		1,194.6			(38.2)			3.6
Beginning balance, treasury stock (in shares) at Dec. 29, 2023						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(134.9)										(134.9)
Other comprehensive income	(0.8)
Ending balance, ordinary shares (in shares) at Sep. 27, 2024			19.7			0.0
Ending balance at Sep. 27, 2024	1,028.3		$ 0.2			$ 0.0		1,198.4			(173.1)			2.8
Beginning balance, ordinary shares (in shares) at Mar. 29, 2024			19.7
Beginning balance at Mar. 29, 2024	1,091.9		$ 0.2			$ 0.0		1,196.5			(103.6)			(1.2)
Beginning balance, treasury stock (in shares) at Mar. 29, 2024						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(43.3)										(43.3)
Other comprehensive income	(3.5)													(3.5)
Share-based compensation	3.4							3.4
Ending balance, ordinary shares (in shares) at Jun. 28, 2024			19.7			0.0
Ending balance at Jun. 28, 2024	1,048.5		$ 0.2			$ 0.0		1,199.9			(146.9)			(4.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(26.2)										(26.2)
Other comprehensive income	7.5													7.5
Share-based compensation	(1.5)							(1.5)
Ending balance, ordinary shares (in shares) at Sep. 27, 2024			19.7			0.0
Ending balance at Sep. 27, 2024	1,028.3		$ 0.2			$ 0.0		1,198.4			(173.1)			2.8
Beginning balance, ordinary shares (in shares) at Dec. 27, 2024			19.7
Beginning balance at Dec. 27, 2024	1,645.8		$ 0.2			$ 0.0		1,199.8			439.7			6.1
Beginning balance, treasury stock (in shares) at Dec. 27, 2024						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(27.7)										(27.7)
Other comprehensive income	3.1													3.1
Share-based compensation	9.7							9.7
Vesting of units, net of tax withholdings (in shares)				0.1			0.0
Vesting of units, net of tax withholdings		$ (1.0)					$ (1.9)		$ 0.9
Share cancellation	0.1							(0.8)			0.9
Ending balance, ordinary shares (in shares) at Mar. 28, 2025			19.8
Ending balance at Mar. 28, 2025	1,630.0		$ 0.2			$ (1.9)		1,209.6			412.9			9.2
Ending balance, treasury stock (in shares) at Mar. 28, 2025						0.0
Beginning balance, ordinary shares (in shares) at Dec. 27, 2024			19.7
Beginning balance at Dec. 27, 2024	1,645.8		$ 0.2			$ 0.0		1,199.8			439.7			6.1
Beginning balance, treasury stock (in shares) at Dec. 27, 2024						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(316.4)
Other comprehensive income	7.2
Ending balance, ordinary shares (in shares) at Sep. 26, 2025			39.4			0.0
Ending balance at Sep. 26, 2025	3,151.3		$ 0.4			$ 0.0		3,016.2			121.4			13.3
Beginning balance, ordinary shares (in shares) at Mar. 28, 2025			19.8
Beginning balance at Mar. 28, 2025	1,630.0		$ 0.2			$ (1.9)		1,209.6			412.9			9.2
Beginning balance, treasury stock (in shares) at Mar. 28, 2025						0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	2.4										2.4
Other comprehensive income	4.7													4.7
Share-based compensation	4.8							4.8
Ending balance, ordinary shares (in shares) at Jun. 27, 2025			19.8			0.0
Ending balance at Jun. 27, 2025	1,641.9		$ 0.2			$ (1.9)		1,214.4			415.3			13.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(291.1)										(291.1)
Other comprehensive income	(0.6)													(0.6)
Share-based compensation	21.0							21.0
Ordinary shares issued in Business Combination (in shares)			19.6
Ordinary shares issued in Business Combination (Note 3)	1,778.4		$ 0.2					1,778.2
Ordinary shares issued (Other)(in shares)			0.0
Ordinary shares issued (Other)	0.7		$ 0.0					0.7
Pre-combination value of converted Endo wards (Note 3) (in shares)			0.0
Pre-combination value of converted Endo awards (Note 3)	1.9		$ 0.0					1.9
Vesting of units, net of tax withholdings (in shares)				0.0	0.0
Vesting of units, net of tax withholdings				$ 0.0	$ 0.0				$ (0.3)	$ (0.6)		$ (0.3)	$ (0.6)
Treasury share cancellation (in shares)						(0.0)
Treasury share cancellation	0.0					$ 1.9					(1.9)
Ending balance, ordinary shares (in shares) at Sep. 26, 2025			39.4			0.0
Ending balance at Sep. 26, 2025	$ 3,151.3		$ 0.4			$ 0.0		$ 3,016.2			$ 121.4			$ 13.3