Accounts Receivable - Net and Revenue Recognition (Details) (USD $)	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 29, 2014	Mar. 30, 2014	Jun. 30, 2013	Jun. 29, 2014	Jun. 30, 2013	Sep. 29, 2013
Accounts Receivable - Net and Revenue Recognition
Billed	$ 307,905,000			$ 307,905,000		$ 375,149,000
Unbilled	381,429,000			381,429,000		306,969,000
Contract retentions	25,885,000			25,885,000		23,353,000
Total accounts receivable - gross	715,219,000			715,219,000		705,471,000
Allowance for doubtful accounts	(40,772,000)			(40,772,000)		(44,624,000)
Total accounts receivable - net	674,447,000			674,447,000		660,847,000
Billings in excess of costs on uncompleted contracts	79,160,000			79,160,000		79,507,000
Period for billing and collecting unbilled receivables				12 months
Period for earning majority of billings in excess of costs				12 months
Total accounts receivable related to claims and requests for equitable adjustment on contracts	86,000,000			86,000,000		41,000,000
Revenue recognized related to the evaluation of claim amounts		3,400,000		3,400,000
Increase in operating income related to the evaluation of claim amounts		3,400,000		3,400,000
Billed accounts receivable related to U.S. federal government contracts	59,500,000			59,500,000		50,500,000
U.S. federal government unbilled receivables, net of progress payments	81,000,000			81,000,000		79,300,000
Threshold percentage for disclosure of accounts receivable from a single client				10.00%		10.00%
Revenue Recognition and Contract Costs
Net unfavorable operating income adjustments	5,000,000			10,300,000
Liability for anticipated losses	10,400,000			10,400,000		13,300,000
Estimated cost to complete the related contracts	37,200,000			37,200,000
Account receivable major customer
Loss on uncollectible accounts receivable related to claims			$ 17,000,000		$ 17,000,000
Accounts Receivable [Member]
Account receivable major customer
Number of clients exceeding threshold				0		0