Consolidated Statements Of Stockholders' Equity And Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013
Statement of Stockholders' Equity [Abstract]
Foreign currency translation tax	$ 586	$ 864	$ (46)	$ 497
Unrealized gains/(losses) on available-for-sale securities, tax	$ 49	$ (87)	$ (131)	$ 493

Amount of tax expense (benefit), after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=36458714&loc=d3e640-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration