Employee Stock Purchase and Stock Option Plans (Number of Shares of Restricted Stock and Restricted Stock Units Issued Under the 1999 Plans) (Details) - shares	12 Months Ended
Sep. 28, 2018	Sep. 29, 2017	Sep. 30, 2016
1999 ODSP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1.92
1999 ODSP \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units outstanding (in shares)	34,000
1999 ODSP \| Restricted Stock Units (RSUs) \| Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued (in shares)	21,620	21,123	23,090
Restricted stock and restricted stock units outstanding (in shares)	91,092
1999 SIP \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued (in shares)	0	0	597,091
Restricted stock and restricted stock units canceled (in shares)	284,254	365,481	512,903
Award number of shares, fungible share basis (in shares)	1.92
Restricted stock and restricted stock units outstanding (in shares)	337,805
1999 SIP \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award number of shares, non-fungible share basis (in shares)	1
Award number of shares, fungible share basis (in shares)	1.92
1999 SIP \| Restricted Stock Units (RSUs) \| Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued (in shares)	1,087,724	496,951	183,131
Restricted stock and restricted stock units canceled (in shares)	336,516	128,536	177,640
Restricted stock and restricted stock units outstanding (in shares)	1,131,200
1999 SIP \| Restricted Stock Units (RSUs) \| Service Market And Performance Conditions at Target
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock and restricted stock units issued (in shares)	254,784	237,058	372,794
Restricted stock and restricted stock units canceled (in shares)	95,063	86,742	275,933
Restricted stock and restricted stock units outstanding (in shares)	735,438

Share-based compensation arrangement by share-based payment award, award number of shares, fungible share basis.

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- Definition

Share-based compensation arrangement by share-based payment award, award number of shares, non-fungible share basis.

+ References

No definition available.

+ Details

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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