Lease Commitments (Details) - USD ($)	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Leases [Abstract]
Sublease income on operating leases	$ 11,200,000
Operating Leases
2017	19,000,000
2018	16,600,000
2019	14,500,000
2020	9,600,000
2021	5,700,000
Thereafter	2,100,000
Total future minimum lease payments	67,500,000
Amortization expense related to capital leases	0	$ 0	$ 200,000
Gross rent expense under operating leases	21,600,000	23,100,000	24,600,000
Sublease income	3,300,000	3,300,000	3,300,000
Accrual for Unused Facilities [Roll Forward]
Accrual for excess facilities - beginning balance	5,500,000	11,300,000
Adjustment of excess facility accrual	0	(4,300,000)
Cash payments	(1,500,000)	(1,500,000)
Accrual for excess facilities - ending balance	4,000,000	5,500,000	11,300,000
Deferred rent	$ 3,900,000	$ 4,600,000	$ 5,200,000