Income Taxes (Schedule of Components of Income from Continuing Operations Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 25, 2020	Dec. 27, 2019
Operating Loss Carryforwards [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 204.9
Domestic	$ (512.2)	(656.9)	$ (75.3)
International	(317.6)	(303.9)	(1,516.2)
Loss from continuing operations before income taxes	(829.8)	(960.8)	(1,591.5)
Ireland
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	2.2	0.2	1.2
Non-U.K.
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 1.2	$ 33.4	$ 0.9