Lease Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Leases [Abstract]
Sublease income on operating leases	$ 14.2
Operating Leases
2016	19.5
2017	16.8
2018	14.5
2019	12.1
2020	7.5
Thereafter	3.1
Total future minimum lease payments	73.5
Amortization expense related to capital leases	0.0	$ 0.2	$ 0.2
Gross rent expense under operating leases	23.1	24.6	20.2
Sublease income	3.3	3.3	2.3
Accrual for Unused Facilities [Roll Forward]
Accrual for excess facilities - beginning balance	11.3	12.4
Adjustment of excess facility accrual	(4.3)	0.2
Cash payments	(1.5)	(1.3)
Accrual for excess facilities - ending balance	5.5	11.3	12.4
Deferred rent	$ 4.6	$ 5.2	$ 3.1