Retirement Plans (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 28, 2018	Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.1	$ 0.0	$ 0.2	$ 1.3
Interest cost	0.2	0.1	0.5	1.7
Expected return on plan assets	0.0	0.0	0.0	(0.8)
Amortization of net actuarial loss	0.1	0.0	0.4	1.8
Amortization of prior service cost	0.0	0.0	0.1	0.2
Plan settlements	(3.4)	0.0	(3.4)	69.7
Net periodic benefit (credit) cost	(3.0)	0.1	(2.2)	73.9
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit (credit) cost	$ (0.1)	$ 0.0	$ (1.1)	$ 0.0