Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
Dec. 31, 2017	Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction to provision for income taxes	$ 755.8	$ 381.4
Earnings per share - diluted	$ 1.57	$ 0.51
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction to provision for income taxes	$ 28.2
Earnings per share - diluted	$ 0.02
Excess tax benefit on share-based awards		$ 34.1
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 28.2

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(19))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Amount of cash inflow from realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-SubTopic 20
-Section 55
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=96864182&loc=d3e11374-113907

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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