Earnings (Loss) per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 27, 2015	Mar. 28, 2014	Mar. 27, 2015	Mar. 28, 2014
Earnings (Loss) per Share [Abstract]
Income from continuing operations attributable to common shareholders before allocation of earnings to participating securities	$ 76.5	$ 11.7	$ 168.6	$ 58.1
Less: earnings allocated to participating securities	0.7	0	1.7	0
Income from continuing operations attributable to common shareholders, after earnings allocated to participating securities	75.8	11.7	166.9	58.1
Income (loss) from discontinued operations, net of income taxes	22.3	(0.1)	22.9	(0.9)
Less: earnings from discontinued operations allocated to participating securities	0.2	0	0.2	0
Income (loss) from discontinued operations attributable to common shareholders, after allocation of earnings to participating securities	22.1	(0.1)	22.7	(0.9)
Net income attributable to common shareholders, after allocation of earnings to participating securities	$ 97.9	$ 11.6	$ 189.6	$ 57.2
Weighted-average shares outstanding - basic (in shares)	115.6	58.2	115.2	58.0
Impact of dilutive securities (in shares)	1.6	0.9	1.6	0.7
Weighted-average shares outstanding - diluted (in shares)	117.2	59.1	116.8	58.7
Income from continuing operations (in usd per share)	$ 0.66	$ 0.20	$ 1.45	$ 1.00
Loss from discontinued operations (in usd per share)	$ 0.19	$ 0.00	$ 0.20	$ (0.02)
Net income (in usd per share)	$ 0.85us-gaap_EarningsPerShareBasic	$ 0.20us-gaap_EarningsPerShareBasic	$ 1.65us-gaap_EarningsPerShareBasic	$ 0.99us-gaap_EarningsPerShareBasic
Income from continuing operations (in usd per share)	$ 0.65	$ 0.20	$ 1.43	$ 0.99
Loss from discontinued operations (in usd per share)	$ 0.19	$ 0.00	$ 0.19	$ (0.02)
Net income attributable to common shareholders (in usd per share)	$ 0.84us-gaap_EarningsPerShareDiluted	$ 0.20us-gaap_EarningsPerShareDiluted	$ 1.62us-gaap_EarningsPerShareDiluted	$ 0.97us-gaap_EarningsPerShareDiluted
Anti-dilutive equity awards excluded from calculation	0	0	0	0

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Income (Loss) From Continuing Operations Attributable To Common Stockholders

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Income (Loss) From Discontinued Operations Attributable To Common Stockholders

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Undistributed Earnings From Discontinued Operations Allocated To Participating Securities

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Per basic share amount, after tax, of income (loss) from the day-to-day business activities of the discontinued operation and gain (loss) from the disposal of the discontinued operation.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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