Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended					0 Months Ended	3 Months Ended
	Dec. 30, 2012	Dec. 25, 2011	Dec. 30, 2012 KGS	Dec. 30, 2012 PSS	Dec. 30, 2012 Southeast Division	Dec. 25, 2011 Southeast Division	Dec. 26, 2010 Southeast Division	Aug. 02, 2010 Southeast Division PSS	Jun. 27, 2010 Southeast Division PSS	Jun. 28, 2009 Southeast Division PSS	Jun. 24, 2012 Southeast Division Discontinued operations KGS
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment charge related to management's estimate of the fair value of the business									$ 0.2	$ 2.0
Cash consideration received from divestiture								0.1
Goodwill impairment charge associated with discontinued operations	82.0		82.0	0							1.5
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Revenue					18.5	9.2	2.2
Loss before taxes					(1.8)	(1.3)	(0.9)
Benefit for income taxes					(0.3)	(0.6)	(0.8)
Net loss					(1.5)	(0.7)	(0.1)
Disposal Group, Including Discontinued Operation, Balance Sheet Disclosures [Abstract]
Accounts receivable, net					3.4	5.3
Inventoried costs					3.0	4.0
Other current assets					0.2	0.4
Current assets of discontinued operations	6.6	9.7			6.6	9.7
Property and equipment, net					0.4	0.6
Goodwill					0	1.5
Other assets					0.4	0.3
Long-term assets of discontinued operations	0.8	2.4			0.8	2.4
Accrued expenses and accounts payable					4.4	3.0
Billings in excess of costs and earnings on uncompleted contracts					0.1	1.5
Other current liabilities					0.4	1.8
Current liabilities of discontinued operations	4.9	6.3			4.9	6.3
Other long-term liabilities					0.3	0.5
Long-term liabilities of discontinued operations	$ 0.3	$ 0.5			$ 0.3	$ 0.5