Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (credit) cost	$ (0.1)	$ 0.0	$ (1.1)	$ 0.0
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (credit) cost	(3.0)	0.1	(2.2)	73.9
Defined Benefit Plan, Plan Assets, Contributions by Employer				61.3
Plan settlements	$ (3.4)	$ 0.0	$ (3.4)	$ 69.7