Revenue Recognition - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Oct. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to retained earnings upon adoption of new accounting guidance	$ (1,071,192)	$ (944,965)
Decrease to contract assets due to adoption of new accounting guidance	(114,324)	(142,882)
Decrease to contract liabilities due to adoption of new accounting guidance	(165,611)	(143,270)
Increase to deferred tax assets due to adoption of new accounting guidance	28,385	8,607
Contract liability revenue recognized during the period	90,000
Liabilities for anticipated losses	11,500	13,600
Estimated cost to complete the related contracts	15,200
Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to retained earnings upon adoption of new accounting guidance			$ 2,800
Accounting Standards Update 2014-09 | Impact of the Adoption of ASC 606
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease to retained earnings upon adoption of new accounting guidance	1,540		2,800
Decrease to contract assets due to adoption of new accounting guidance	3,426		5,000
Decrease to contract liabilities due to adoption of new accounting guidance	2,710		1,100
Increase to deferred tax assets due to adoption of new accounting guidance			$ 1,100
CIG
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net unfavorable operating income adjustments	$ 800	$ 11,200