Accounts Receivable - Net (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 29, 2013	Sep. 29, 2013
Accounts Receivable - Net
Billed	$ 356,496,000	$ 375,149,000
Unbilled	312,982,000	306,969,000
Contract retentions	20,170,000	23,353,000
Total accounts receivable - gross	689,648,000	705,471,000
Allowance for doubtful accounts	(46,751,000)	(44,624,000)
Total accounts receivable - net	642,897,000	660,847,000
Billings in excess of costs on uncompleted contracts	92,179,000	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	39,000,000	41,000,000
Billed accounts receivable related to U.S. federal government contracts	61,800,000	50,500,000
U.S. federal government unbilled receivables, net of progress payments	$ 81,300,000	$ 79,300,000
Threshold percentage for disclosure of accounts receivable from a single client	10.00%	10.00%
Accounts Receivable
Account receivable major customer
Number of clients exceeding threshold	0	0