Lease Commitments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 30, 2012	Dec. 25, 2011	Dec. 26, 2010
Leases [Abstract]
Sublease income on operating leases	$ 10.1
Capital Leases
2013	0.6
2014	0.4
2015	0.1
2016	0
2017	0
Thereafter	0
Total future minimum lease payments	1.1
Less amount representing interest	0.2
Present value of capital lease obligations	0.9
Less current portion	0.5	0.6
Capital lease obligations, net of current portion	0.4	0.7
Net Operating Leases
2013	18.4
2014	18.4
2015	16.2
2016	14.1
2017	13.0
Thereafter	23.3
Total future minimum lease payments	103.4
Capital Leased Assets [Line Items]
Property under capital leases by major class, gross	2.7	2.3
Less: Accumulated amortization	1.5	1.0
Property under capital leases by major class, net	1.2	1.3
Liabiity for unused facilities at fair value	18.7	18.5	0.1
Amortization expense related to capital leases	0.1	0.1	0.3
Gross rent expense under operating leases	21.1	12.8	6.8
Sublease income	2.7	1.3	0.2
Accrual for Unused Facilities [Roll Forward]
Accrual for excess facilities - beginning balance	18.5	0.1
Fair value of liability assumed in acquisition		19.0
Adjustments	1.8
Cash payments	(1.6)	(0.6)
Accrual for excess facilities - ending balance	18.7	18.5	0.1
Deferred rent	1.3	1.0	1.2
Integral
Capital Leased Assets [Line Items]
Rentable area of acquired property		131,450
Area subleased		83,000
Liabiity for unused facilities at fair value		19.0
Accrual for Unused Facilities [Roll Forward]
Accrual for excess facilities - ending balance		19.0
Facilities
Capital Leased Assets [Line Items]
Property under capital leases by major class, gross	1.6	1.0
Vehicles
Capital Leased Assets [Line Items]
Property under capital leases by major class, gross	0.5	0.6
Office equipment
Capital Leased Assets [Line Items]
Property under capital leases by major class, gross	$ 0.6	$ 0.7