Condensed Consolidating Financial Statements - Balance Sheet (Details) (USD $)	Jun. 29, 2014	Dec. 29, 2013	Jun. 30, 2013	Dec. 30, 2012	Jun. 29, 2014 Subsidiaries	Jun. 29, 2014 Parent Company	Dec. 29, 2013 Parent Company	Jun. 29, 2014 Guarantors on a Combined Basis	Dec. 29, 2013 Guarantors on a Combined Basis	Jun. 29, 2014 Non-Guarantors on a Combined Basis	Dec. 29, 2013 Non-Guarantors on a Combined Basis	Jun. 29, 2014 Eliminations	Dec. 29, 2013 Eliminations	Jun. 29, 2014 Senior notes 7.00% Senior Notes due 2019	May 31, 2014 Senior notes 7.00% Senior Notes due 2019
Condensed Financial Statements, Captions [Line Items]
Principal	$ 670,200,000	$ 629,800,000												$ 625,000,000	$ 625,000,000.0
Ownership percentage					100.00%
Current assets:
Cash and cash equivalents	26,900,000	55,700,000	49,700,000	49,000,000		22,100,000	42,700,000	(5,300,000)	(3,000,000)	10,100,000	16,000,000	0	0
Accounts receivable, net	265,900,000	265,800,000				0	0	237,100,000	238,600,000	28,800,000	27,200,000	0	0
Amounts due from affiliated companies	0	0				389,500,000	410,200,000	0	0	0	0	(389,500,000)	(410,200,000)
Inventoried costs	78,500,000	74,600,000				0	0	59,800,000	59,100,000	18,700,000	15,500,000	0	0
Other current assets	27,200,000	34,200,000				6,500,000	10,700,000	16,100,000	19,400,000	4,600,000	4,100,000	0	0
Total current assets	398,500,000	430,300,000				418,100,000	463,600,000	307,700,000	314,100,000	62,200,000	62,800,000	(389,500,000)	(410,200,000)
Property, plant and equipment, net	84,200,000	84,800,000				2,200,000	2,100,000	71,200,000	71,900,000	10,800,000	10,800,000	0	0
Goodwill	596,400,000	596,400,000				0	0	572,400,000	574,800,000	24,000,000	21,600,000	0	0
Intangible assets, net	62,600,000	69,900,000				0	0	61,900,000	68,500,000	700,000	1,400,000	0	0
Investment in subsidiaries	0	0				487,800,000	474,200,000	39,000,000	36,700,000	0	0	(526,800,000)	(510,900,000)
Amounts due from affiliated companies	0	0				0	0	24,000,000	24,000,000	0	0	(24,000,000)	(24,000,000)
Other assets	30,400,000	35,200,000				8,100,000	12,900,000	22,200,000	23,000,000	100,000	(700,000)	0	0
Total assets	1,172,100,000	1,216,600,000				916,200,000	952,800,000	1,098,400,000	1,113,000,000	97,800,000	95,900,000	(940,300,000)	(945,100,000)
Current liabilities:
Accounts payable	70,100,000	61,900,000				3,400,000	2,800,000	61,400,000	54,100,000	5,300,000	5,000,000	0	0
Accrued expenses	46,500,000	51,400,000				7,700,000	6,600,000	35,600,000	40,900,000	3,200,000	3,900,000	0	0
Accrued compensation	38,700,000	44,900,000				4,300,000	4,000,000	30,800,000	36,900,000	3,600,000	4,000,000	0	0
Billings in excess of costs and earnings on uncompleted contracts	49,200,000	52,500,000				0	0	41,900,000	45,400,000	7,300,000	7,100,000	0	0
Deferred income tax liability	28,400,000	28,400,000				(800,000)	0	29,200,000	28,400,000	0	0	0	0
Amounts due to affiliated companies	0	0				0	0	368,800,000	390,200,000	20,700,000	20,000,000	(389,500,000)	(410,200,000)
Other current liabilities	14,000,000	11,900,000				2,100,000	1,300,000	10,800,000	9,500,000	1,100,000	1,100,000	0	0
Total current liabilities	246,900,000	251,000,000				16,700,000	14,700,000	578,500,000	605,400,000	41,200,000	41,100,000	(389,500,000)	(410,200,000)
Long-term debt, net of current portion	662,900,000	643,300,000				659,600,000	639,500,000	0		3,300,000	3,800,000	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	25,200,000	26,500,000				2,800,000	2,800,000	20,100,000	21,400,000	2,300,000	2,300,000	0	0
Total liabilities	935,000,000	920,800,000				679,100,000	657,000,000	598,600,000	626,800,000	70,800,000	71,200,000	(413,500,000)	(434,200,000)
Total stockholders' equity	237,100,000	295,800,000				237,100,000	295,800,000	499,800,000	486,200,000	27,000,000	24,700,000	(526,800,000)	(510,900,000)
Total liabilities and stockholders’ equity	$ 1,172,100,000	$ 1,216,600,000				$ 916,200,000	$ 952,800,000	$ 1,098,400,000	$ 1,113,000,000	$ 97,800,000	$ 95,900,000	$ (940,300,000)	$ (945,100,000)