Basis Of Presentation And Summary Of Significant Accounting Policies (Activity For Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 26, 2015	Sep. 27, 2014	Sep. 28, 2013
Basis Of Presentation And Summary Of Significant Accounting Policies [Abstract]
Allowance for doubtful accounts, beginning	$ 3	$ 3	$ 3
Bad debt expense	2		1
Write-offs against allowance	(2)		(1)
Allowance for doubtful accounts, ending	$ 3	$ 3	$ 3

Amount of direct write-downs of accounts receivable charged against the allowance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 954
-SubTopic 310
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35755819&loc=SL9156395-115594

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.4)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration