Defined Benefit Plans (Components of Net Periodic Benefit Cost of Other Postretirement Benefit Pension Pans) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (9.8)	$ (11.2)	$ (19.6)	$ (22.1)
Net periodic benefit cost	(3.5)	(2.9)	(8.1)	(6.0)
Other postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	(0.1)	(0.2)	(0.2)	(0.3)
Interest cost	(1.3)	(1.1)	(2.5)	(2.3)
Amortization of prior service (cost) credit	0.5	0.6	1.0	1.2
Net periodic benefit cost	$ (0.9)	$ (0.7)	$ (1.7)	$ (1.4)