Retirement Plans (Schedule of Benefit Obligation, Plan Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 27, 2019	Dec. 28, 2018	Dec. 29, 2017
Pension Benefits
Change in benefit obligations:
Projected benefit obligations at beginning of year	$ 26.1	$ 27.8
Service cost	0.1	0.2	$ 1.4
Interest cost	0.7	0.6	2.3
Actuarial loss (gain)	2.3	0.7
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(1.7)	(1.6)
Plan settlements	(0.2)	(0.8)
Currency translation	(0.3)	(0.8)
Projected benefit obligations at end of year	27.0	26.1	27.8
Change in plan assets:
Employer contributions	1.9	2.4
Funded status at end of year	(27.0)
Postretirement Benefits
Change in benefit obligations:
Projected benefit obligations at beginning of year	39.8	45.6
Service cost	0.0	0.0	0.0
Interest cost	1.6	1.5	1.7
Actuarial loss (gain)	1.7	(3.9)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(2.6)	(2.7)
Plan settlements	0.0	(0.7)
Currency translation	0.0	0.0
Projected benefit obligations at end of year	$ 40.5	$ 39.8	$ 45.6