Condensed Consolidating Financial Statements - Balance Sheet (Details) (USD $)	Mar. 30, 2014	Dec. 29, 2013	Mar. 31, 2013	Dec. 30, 2012
Condensed Financial Statements, Captions [Line Items]
Principal	$ 629,500,000.0	$ 629,800,000.0
Current assets:
Cash and cash equivalents	53,600,000	55,700,000	51,600,000	49,000,000
Accounts receivable, net	248,000,000	265,800,000
Amounts due from affiliated companies	0	0
Inventoried costs	81,100,000	74,600,000
Other current assets	30,600,000	34,200,000
Total current assets	413,300,000	430,300,000
Property, plant and equipment, net	84,000,000	84,800,000
Goodwill	596,400,000	596,400,000
Intangible assets, net	64,300,000	69,900,000
Investment in subsidiaries	0	0
Amounts due from affiliated companies	0	0
Other assets	38,400,000	35,200,000
Total assets	1,196,400,000	1,216,600,000
Current liabilities:
Accounts payable	48,200,000	61,900,000
Accrued expenses	61,900,000	51,400,000
Accrued compensation	38,700,000	44,900,000
Billings in excess of costs and earnings on uncompleted contracts	54,500,000	52,500,000
Deferred income tax liability	28,400,000	28,400,000
Amounts due to affiliated companies	0	0
Other current liabilities	12,400,000	11,900,000
Total current liabilities	244,100,000	251,000,000
Long-term debt, net of current portion	642,000,000	643,300,000
Amounts due to affiliated companies	0	0
Other long-term liabilities	26,200,000	26,500,000
Total liabilities	912,300,000	920,800,000
Total stockholders' equity	284,100,000	295,800,000
Total liabilities and stockholders’ equity	1,196,400,000	1,216,600,000
Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Ownership percentage	100.00%
Parent Company
Current assets:
Cash and cash equivalents	41,100,000	42,700,000
Accounts receivable, net	0	0
Amounts due from affiliated companies	410,600,000	410,200,000
Inventoried costs	0	0
Other current assets	6,400,000	10,700,000
Total current assets	458,100,000	463,600,000
Property, plant and equipment, net	2,200,000	2,100,000
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	480,600,000	474,200,000
Amounts due from affiliated companies	0	0
Other assets	11,600,000	12,900,000
Total assets	952,500,000	952,800,000
Current liabilities:
Accounts payable	2,300,000	2,800,000
Accrued expenses	22,100,000	6,600,000
Accrued compensation	2,400,000	4,000,000
Billings in excess of costs and earnings on uncompleted contracts	0	0
Deferred income tax liability	(800,000)	0
Amounts due to affiliated companies	0	0
Other current liabilities	1,100,000	1,300,000
Total current liabilities	27,100,000	14,700,000
Long-term debt, net of current portion	638,500,000	639,500,000
Amounts due to affiliated companies	0	0
Other long-term liabilities	2,800,000	2,800,000
Total liabilities	668,400,000	657,000,000
Total stockholders' equity	284,100,000	295,800,000
Total liabilities and stockholders’ equity	952,500,000	952,800,000
Guarantors on a Combined Basis
Current assets:
Cash and cash equivalents	(2,800,000)	(3,000,000)
Accounts receivable, net	223,300,000	238,600,000
Amounts due from affiliated companies	0	0
Inventoried costs	64,800,000	59,100,000
Other current assets	20,000,000	19,400,000
Total current assets	305,300,000	314,100,000
Property, plant and equipment, net	71,200,000	71,900,000
Goodwill	572,400,000	574,800,000
Intangible assets, net	63,200,000	68,500,000
Investment in subsidiaries	38,200,000	36,700,000
Amounts due from affiliated companies	24,000,000	24,000,000
Other assets	26,800,000	23,000,000
Total assets	1,101,100,000	1,113,000,000
Current liabilities:
Accounts payable	42,200,000	54,100,000
Accrued expenses	36,000,000	40,900,000
Accrued compensation	32,400,000	36,900,000
Billings in excess of costs and earnings on uncompleted contracts	47,700,000	45,400,000
Deferred income tax liability	29,200,000	28,400,000
Amounts due to affiliated companies	389,600,000	390,200,000
Other current liabilities	10,200,000	9,500,000
Total current liabilities	587,300,000	605,400,000
Long-term debt, net of current portion	0
Amounts due to affiliated companies	0	0
Other long-term liabilities	21,200,000	21,400,000
Total liabilities	608,500,000	626,800,000
Total stockholders' equity	492,600,000	486,200,000
Total liabilities and stockholders’ equity	1,101,100,000	1,113,000,000
Non-Guarantors on a Combined Basis
Current assets:
Cash and cash equivalents	15,300,000	16,000,000
Accounts receivable, net	24,700,000	27,200,000
Amounts due from affiliated companies	0	0
Inventoried costs	16,300,000	15,500,000
Other current assets	4,200,000	4,100,000
Total current assets	60,500,000	62,800,000
Property, plant and equipment, net	10,600,000	10,800,000
Goodwill	24,000,000	21,600,000
Intangible assets, net	1,100,000	1,400,000
Investment in subsidiaries	0	0
Amounts due from affiliated companies	0	0
Other assets	0	(700,000)
Total assets	96,200,000	95,900,000
Current liabilities:
Accounts payable	3,700,000	5,000,000
Accrued expenses	3,800,000	3,900,000
Accrued compensation	3,900,000	4,000,000
Billings in excess of costs and earnings on uncompleted contracts	6,800,000	7,100,000
Deferred income tax liability	0	0
Amounts due to affiliated companies	21,000,000	20,000,000
Other current liabilities	1,100,000	1,100,000
Total current liabilities	40,300,000	41,100,000
Long-term debt, net of current portion	3,500,000	3,800,000
Amounts due to affiliated companies	24,000,000	24,000,000
Other long-term liabilities	2,200,000	2,300,000
Total liabilities	70,000,000	71,200,000
Total stockholders' equity	26,200,000	24,700,000
Total liabilities and stockholders’ equity	96,200,000	95,900,000
Eliminations
Current assets:
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Amounts due from affiliated companies	(410,600,000)	(410,200,000)
Inventoried costs	0	0
Other current assets	0	0
Total current assets	(410,600,000)	(410,200,000)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	(518,800,000)	(510,900,000)
Amounts due from affiliated companies	(24,000,000)	(24,000,000)
Other assets	0	0
Total assets	(953,400,000)	(945,100,000)
Current liabilities:
Accounts payable	0	0
Accrued expenses	0	0
Accrued compensation	0	0
Billings in excess of costs and earnings on uncompleted contracts	0	0
Deferred income tax liability	0	0
Amounts due to affiliated companies	(410,600,000)	(410,200,000)
Other current liabilities	0	0
Total current liabilities	(410,600,000)	(410,200,000)
Long-term debt, net of current portion	0	0
Amounts due to affiliated companies	(24,000,000)	(24,000,000)
Other long-term liabilities	0	0
Total liabilities	(434,600,000)	(434,200,000)
Total stockholders' equity	(518,800,000)	(510,900,000)
Total liabilities and stockholders’ equity	(953,400,000)	(945,100,000)
Senior notes | Senior Notes due June 2017
Condensed Financial Statements, Captions [Line Items]
Principal	$ 625,000,000