Retirement Plans (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2018	Mar. 31, 2017
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.1	$ 1.1
Interest cost	0.2	1.2
Expected return on plan assets	0.0	(0.8)
Amortization of net actuarial loss	0.1	1.5
Amortization of prior service cost	0.0	0.1
Plan settlements	0.0	69.2
Net periodic benefit cost	0.4	$ 72.3
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ (0.3)