Stock-based Compensation (Narrative) (Details)	3 Months Ended
	Dec. 30, 2017 USD ($) shares / unit	Dec. 31, 2016 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Common Stock Issuable per Restricted Stock Unit | shares / unit	1
ESPP maximum contribution percentage	10.00%
ESPP maximum contribution amount by employee	$ 25,000
ESPP purchase price as a % of stock price	85.00%
Stock-based compensation	$ 18,331,000	$ 17,988,000
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1,100,000	$ 600,000