Pension and Other Post Retirement Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2019	Sep. 27, 2018	Sep. 26, 2019	Sep. 27, 2018
Pension And Other Post Retirement Benefits Textuals [Abstract]
Defined Benefit Plan Estimated Future Employer Contributions Remainder Of Year			$ 6.9
Expected UK Pension Plan Contribution For The Year			1.7
Defined Benefit Plans [Member]
Pension and Other Post-Retirement Benefits
Service cost	$ (0.3)	$ (0.2)	(1.0)	$ (0.6)
Interest cost	(10.0)	(9.2)	(30.0)	(27.4)
Expected return on plan assets	(16.6)	(17.4)	(50.0)	(52.3)
Amortization of net loss	0.1	0.0	0.5	0.0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits	(5.5)	0.0	9.7	0.0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment			(0.1)
Net periodic pension income	(11.7)	(8.0)	(8.9)	(24.3)
Other Benefits [Member]
Pension and Other Post-Retirement Benefits
Service cost	(0.2)	(0.3)	(0.7)	(0.8)
Interest cost	(0.3)	(0.3)	(1.0)	(0.8)
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	(0.2)	(0.2)	(0.7)	(0.7)
Amortization of net loss	(0.6)	(0.6)	(1.8)	(1.7)
Net periodic pension income	$ (0.3)	$ (0.2)	$ (0.8)	$ (0.8)