Defined Benefit Plans (Components of Net Periodic Benefit Cost of Other Postretirement Benefit Pension Pans) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (6.1)	$ (7.5)
Net periodic benefit (cost)	(0.8)	(2.4)
Other postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	(0.1)	(0.1)
Interest cost	(0.8)	(1.2)
Amortization of prior service (cost) credit	0.5	0.5
Net periodic benefit (cost)	$ (0.4)	$ (0.8)