Basis of Presentation and Preparation (Details 4) (USD $)	3 Months Ended								12 Months Ended
	Sep. 28, 2014	Jun. 29, 2014	Mar. 30, 2014	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 30, 2012	Sep. 28, 2014	Sep. 29, 2013	Sep. 30, 2012
Revenue recognition and contract costs
Favorable (unfavorable) operating income adjustments	$ 24,763,000	$ 39,167,000	$ 46,186,000	$ 43,718,000	$ 40,626,000	$ (99,884,000)	$ 37,667,000	$ 41,809,000	$ 153,833,000	$ 20,218,000	$ 166,367,000
Liability for anticipated losses	18,600,000				13,300,000				18,600,000	13,300,000
Estimated cost to complete the related contracts	103,000,000								103,000,000
Contracts accounted for under the percentage-of-completion method of accounting
Revenue recognition and contract costs
Favorable (unfavorable) operating income adjustments									$ (35,900,000)	$ (40,100,000)	$ 500,000