Acquisitions - Contingent Acquisition Consideration (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended
	Apr. 30, 2012	Dec. 30, 2012	Dec. 25, 2011
Business Acquisition, Contingent Consideration [Roll Forward]
Beginning balance		$ 7.6	$ 5.8
Change in fair value of contingent acquisition consideration			1.5
Cash payments		(4.0)
Post acquisition adjustments reflected in operating results		(1.5)	0.3
Ending balance		2.1	7.6
Other current assets
Business Acquisition, Contingent Consideration [Roll Forward]
Ending balance		2.1
SecureInfo
Business Acquisition, Contingent Consideration [Roll Forward]
Beginning balance		1.5	0
Change in fair value of contingent acquisition consideration			1.5
Cash payments		(1.5)
Post acquisition adjustments reflected in operating results		0	0
Ending balance		0	1.5
DEI
Business Acquisition, Contingent Consideration [Roll Forward]
Beginning balance		5.0	4.6
Change in fair value of contingent acquisition consideration		(2.9)	0
Cash payments	(2.5)	(2.5)
Post acquisition adjustments reflected in operating results		(0.4)	0.4
Ending balance		2.1	5.0
SCT
Business Acquisition, Contingent Consideration [Roll Forward]
Beginning balance		1.1	1.2
Change in fair value of contingent acquisition consideration		1.1	0
Cash payments		0
Post acquisition adjustments reflected in operating results		(1.1)	(0.1)
Ending balance		0	1.1
Low range of potential undiscounted amount of all future contingent consideration payable		0
High range of potential undiscounted amount of all future contingent consideration payable		$ 3.5
Discount rate used in valuing contingent consideration		6.10%