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Employee Stock Purchase and Stock Option Plans (Unvested Restricted Stock and Restricted Stock Units Roll Forward) (Details) - $ / shares | 12 Months Ended
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Sep. 28, 2018 | Sep. 29, 2017 | Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] |  |  |
Granted (in dollars per share) | $ 0.00 | $ 0.00 | $ 12.80
Restricted Stock And Restricted Stock Units |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward] |  |  |
Beginning balance outstanding (in shares) | 2,514,387 |  |
Granted (in shares) | 1,364,128 |  |
Vested (in shares) | (1,209,322) |  |
Canceled (in shares) | (339,658) |  |
Ending balance outstanding (in shares) | 2,329,535 | 2,514,387 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] |  |  |
Beginning balance outstanding (in dollars per share) | $ 49.62 |  |
Granted (in dollars per share) | 65.64 |  |
Vested (in dollars per share) | 55.19 |  |
Canceled (in dollars per share) | 49.57 |  |
Ending balance outstanding (in dollars per share) | $ 56.11 | $ 49.62 |

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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + 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 (d)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition Weighted average grant-date fair value of options vested. + References No definition available. + Details
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