Consolidated Statement of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Ordinary Shares	Treasury Shares	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjustment [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	$ 15.9							$ 15.9
Beginning balance, shares at Dec. 28, 2018			92,700,000	9,400,000
Beginning balance, value at Dec. 28, 2018	2,887.3		$ 18.5	$ (1,617.4)	$ 5,528.2	$ (1,017.7)		(24.3)
Beginning balance, value (Accounting Standards Update 2018-02 [Member]) at Dec. 28, 2018		$ 0.0					$ (0.5)		$ 0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (996.5)					(996.5)
Share options exercised, shares	45,324
Share options exercised, value	$ 0.6				0.6
Vesting of restricted shares, shares			800,000	200,000
Vesting of restricted shares, value	2.5		$ (0.2)	$ 2.6	0.1
Share-based compensation	$ 33.8				33.8
Stock Issued During Period, Shares, Treasury Stock Reissued	(200,000)
Stock Issued During Period, Value, Treasury Stock Reissued	$ (2.1)			$ (4.3)		(2.2)
Ending balance, shares at Dec. 27, 2019			93,500,000	9,400,000
Ending balance, value at Dec. 27, 2019	1,940.7		$ 18.7	$ (1,615.7)	5,562.5	(2,016.9)		(7.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	(1.7)							(1.7)
Net loss	(944.6)					(944.6)
Vesting of restricted shares, shares			600,000	100,000
Vesting of restricted shares, value	0.5		$ (0.1)	$ 0.4	0.2
Share-based compensation	25.3				25.3
Ending balance, shares at Dec. 25, 2020			94,100,000	9,500,000
Ending balance, value at Dec. 25, 2020	1,019.2		$ 18.8	$ (1,616.1)	5,587.6	(2,961.5)		(9.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	1.3							1.3
Net loss	(717.4)					(717.4)
Vesting of restricted shares, shares			200,000	100,000
Vesting of restricted shares, value	(0.1)		$ (0.1)	$ 0.0	0.0
Share-based compensation	10.2				10.2
Ending balance, shares at Dec. 31, 2021			94,300,000	9,600,000
Ending balance, value at Dec. 31, 2021	$ 313.4		$ 18.9	$ (1,616.1)	$ 5,597.8	$ (3,678.9)		$ (8.3)