Condensed Consolidating Financial Statements - Balance Sheet (Details) (USD $)	Dec. 29, 2013	Dec. 30, 2012	Dec. 25, 2011	Dec. 26, 2010	Dec. 29, 2013 Parent Company	Dec. 30, 2012 Parent Company	Dec. 29, 2013 Guarantors on a Combined Basis	Dec. 30, 2012 Guarantors on a Combined Basis	Dec. 29, 2013 Non-Guarantors on a Combined Basis	Dec. 30, 2012 Non-Guarantors on a Combined Basis	Dec. 29, 2013 Eliminations	Dec. 30, 2012 Eliminations	Dec. 29, 2013 Senior notes Senior Notes due June 2017	Jul. 27, 2011 Senior notes Senior Notes due June 2017	Mar. 25, 2011 Senior notes Senior Notes due June 2017	May 19, 2010 Senior notes Senior Notes due June 2017
Condensed Financial Statements, Captions [Line Items]
Principal	$ 629,800,000	$ 630,700,000											$ 625,000,000	$ 115,000,000	$ 285,000,000	$ 225,000,000
Current assets:
Cash and cash equivalents	55,700,000	49,000,000	69,600,000	10,800,000	42,700,000	37,800,000	(3,000,000)	(4,000,000)	16,000,000	15,200,000	0	0
Accounts receivable, net	265,800,000	271,900,000			0	0	238,600,000	253,500,000	27,200,000	18,400,000	0	0
Amounts due from affiliated companies	0	0			410,200,000	480,200,000	0	0	0	0	(410,200,000)	(480,200,000)
Inventoried costs	74,600,000	94,300,000			0	0	59,100,000	75,400,000	15,500,000	18,900,000	0	0
Other current assets	34,200,000	40,200,000			10,700,000	9,100,000	19,400,000	28,000,000	4,100,000	3,100,000	0	0
Total current assets	430,300,000	455,400,000			463,600,000	527,100,000	314,100,000	352,900,000	62,800,000	55,600,000	(410,200,000)	(480,200,000)
Amounts due from affiliated companies, long-term	0	0			0	0	24,000,000	24,000,000	0	0	(24,000,000)	(24,000,000)
Property, plant and equipment, net	84,800,000	85,600,000			2,100,000	1,300,000	71,900,000	74,700,000	10,800,000	9,600,000	0	0
Goodwill	596,400,000	596,400,000			0	0	574,800,000	574,700,000	21,600,000	21,700,000	0	0
Intangible assets, net	69,900,000	106,100,000			0	0	68,500,000	103,400,000	1,400,000	2,700,000	0	0
Investment in subsidiaries	0	0			474,200,000	439,800,000	36,700,000	28,800,000	0	0	(510,900,000)	(468,600,000)
Other assets	35,200,000	40,400,000			12,900,000	17,600,000	23,000,000	22,400,000	(700,000)	400,000	0	0
Total assets	1,216,600,000	1,283,900,000			952,800,000	985,800,000	1,113,000,000	1,180,900,000	95,900,000	90,000,000	(945,100,000)	(972,800,000)
Current liabilities:
Accounts payable	61,900,000	83,600,000			2,800,000	2,800,000	54,100,000	75,200,000	5,000,000	5,600,000	0	0
Accrued expenses	51,400,000	52,700,000			6,600,000	7,000,000	40,900,000	42,300,000	3,900,000	3,400,000	0	0
Accrued compensation	44,900,000	47,800,000			4,000,000	2,900,000	36,900,000	41,800,000	4,000,000	3,100,000	0	0
Billings in excess of costs and earnings on uncompleted contracts	52,500,000	43,700,000			0	0	45,400,000	40,500,000	7,100,000	3,200,000	0	0
Deferred income tax liability	28,400,000	28,900,000			0	0	28,400,000	28,900,000	0	0	0	0
Amounts due to affiliated companies	0	0			0	0	390,200,000	455,100,000	20,000,000	25,100,000	(410,200,000)	(480,200,000)
Other current liabilities	11,900,000	22,100,000			1,300,000	1,100,000	9,500,000	19,100,000	1,100,000	1,900,000	0	0
Total current liabilities	251,000,000	278,800,000			14,700,000	13,800,000	605,400,000	702,900,000	41,100,000	42,300,000	(410,200,000)	(480,200,000)
Long-term debt, net of current portion	643,300,000	648,400,000			639,500,000	643,600,000	0	0	3,800,000	4,800,000	0	0
Deferred tax liability	700,000	0				0		0		0		0
Amounts due to affiliated companies	0	0			0	0	0	0	24,000,000	24,000,000	(24,000,000)	(24,000,000)
Other long-term liabilities	26,500,000	32,600,000			2,800,000	4,300,000	21,400,000	26,200,000	2,300,000	2,100,000	0	0
Total liabilities	920,800,000	959,800,000			657,000,000	661,700,000	626,800,000	729,100,000	71,200,000	73,200,000	(434,200,000)	(504,200,000)
Total stockholders' equity	295,800,000	324,100,000	312,600,000	169,900,000	295,800,000	324,100,000	486,200,000	451,800,000	24,700,000	16,800,000	(510,900,000)	(468,600,000)
Total liabilities and stockholders' equity	$ 1,216,600,000	$ 1,283,900,000			$ 952,800,000	$ 985,800,000	$ 1,113,000,000	$ 1,180,900,000	$ 95,900,000	$ 90,000,000	$ (945,100,000)	$ (972,800,000)