Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit credit	$ (0.3)
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit credit	0.4	$ 72.3
Defined Benefit Plan, Plan Assets, Contributions by Employer		61.3
Plan settlements	$ 0.0	$ 69.2