Stockholders' Equity (Employee Stock Benefit Plans) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
Sep. 27, 2019	Sep. 28, 2018	Sep. 29, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	85.3
Options outstanding (in shares)	1.3	1.9
Shares available for grant (in shares)	12.4
Employee Contributions To ESPP	10.00%
Weighted average grant fair value, grants in period	$ 21.74	$ 68.32	$ 23.25
Fair value of shares vested in period	$ 23.7	$ 22.6	$ 19.3
Capitalized stock based compensation	4.7	2.9	4.0
Share-based compensation	$ 80.1	$ 107.8	$ 88.5
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	19.4
Options outstanding (in shares)	1.3
Shares available for grant (in shares)	11.7
Contractual life maximum	7 years
Vesting period	4 years
Vesting restricted stock awards period maximum	4 years
Equity incentive plan performance shares maximum vesting period	3 years
Director Long Term Incentive Plan 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	1.5
Shares available for grant (in shares)	0.6
Contractual life maximum	10 years
Vesting period	4 years
Vesting restricted stock awards period maximum	1 year
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	9.7
ESPP shares issued (in shares)	0.3	0.2	0.2
Shares available for grant (in shares)	0.2
Percent of market price	85.00%
Share-based compensation	$ 5.8	$ 5.2	$ 4.5
Unrecognized Compensation Cost for unvested awards	$ 1.9
Weighted average remaining recognition period (in years)	3 months 30 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost for unvested awards	$ 129.6
Weighted average remaining recognition period (in years)	1 year 8 months 12 days

Employee Contribution Percentage to Employee Stock Purchase Plan

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Employeeincentiveplansoptionscontractuallifemaximum - maximum number of years for the company's stock options before they expire

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Equity Incentive Plan Performance Based Share Awards Vesting - Vesting for performance based awards

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Equity Incenctive Restricted Stock Awards Vesting - number of years to full vest

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ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentOfMarketPrice

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Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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