Revenue Recognition - Cash Flow Statement Impact of Adoption of ASC 606 (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Oct. 01, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net income	$ 158,761	$ 136,957	$ 117,917
Deferred income taxes	(37,615)	(29,360)	(9,957)
Accounts receivable and contract assets	(10,226)	(46,273)	(64,781)
Contract liabilities	(6,039)	15,228	28,298
Net cash provided by operating activities	208,513	$ 185,733	$ 141,487
Recognition Under Previous Guidance
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net income	157,535
Deferred income taxes	(38,116)
Accounts receivable and contract assets	(17,434)
Contract liabilities	2,896
Net cash provided by operating activities	208,513
Impact of the Adoption of ASC 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net income	1,226
Deferred income taxes	501
Accounts receivable and contract assets	7,208
Contract liabilities	(8,935)
Net cash provided by operating activities	$ 0