Summary Of Significant Accounting Policies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Summary Of Significant Accounting Policies [Line Items]
Maximum credit exposure (percent)	5.00%
Advertising expense	$ 47,402	$ 44,221	$ 46,202
Transaction and re-measurement gains/losses	$ (74)	(474)	$ (142)
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets with definite lives, useful life, minimum years	3 years
Minimum [Member] | Internal Use Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets with definite lives, useful life, minimum years	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets with definite lives, useful life, minimum years	18 years
Corrective royalties, percentage of license revenue (percent)	1.00%
Maximum [Member] | Internal Use Software [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangible assets with definite lives, useful life, minimum years	5 years
Foreign Exchange Forward [Member]
Summary Of Significant Accounting Policies [Line Items]
Notional amount of derivative	$ 24,500	$ 18,300
Customer Concentration Risk [Member] | Sales Revenue, Goods, Net [Member]
Summary Of Significant Accounting Policies [Line Items]
Percent of revenue from significant customer (percent)			12.00%