Income Taxes (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Mar. 31, 2012	Sep. 30, 2011
Income Tax Contingency [Line Items]
Gross Unrecognized Tax Benefits	$ 77.0	$ 75.1
Net unrecognized tax benefits	32.1	30.2
Income Taxes (Textual) [Abstract]
Effective income tax rate	24.70%
Statutory tax rate	35.00%
Reasonably possible amount of increase / (decrease) in unrecognized tax benefits for the next twelve months	9.8
Reasonably possible amount of increase / (decrease) in offsetting tax benefits for the next twelve months	0.9
Accrued interest and penalties for unrecognized tax benefits	$ 20.3	$ 16.9

A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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The domestic federal statutory tax rate applicable under enacted tax laws to the Company's pretax income from continuing operations for the period. The "statutory" tax rate is the regular tax rate if there are alternative tax systems.

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- Definition

This element represents the total of accruals as of the date of the statement of financial position for interest recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties for a tax position claimed or expected to be claimed by the entity, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

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