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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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The amount of the additional liability or refund received or expected based on a final settlement with a taxing authority.

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The tax year(s) being audited in connection with the income tax examination.

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The estimated lower bound of the reasonably possible change in the total amount of the unrecognized tax benefit (that will significantly increase or decrease within twelve months of the balance sheet date) for a tax position taken.

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The estimated upper bound of the reasonably possible change in the total amount of the unrecognized tax benefit (that will significantly increase or decrease within twelve months of the balance sheet date) for a tax position taken.

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Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings.

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The gross amount of decreases in unrecognized tax benefits resulting from settlements with taxing authorities.

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Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended	3 Months Ended
	Apr. 30, 2012	Oct. 31, 2011	Jul. 31, 2012 Non-U.S. Examinations [Member]	Apr. 30, 2012 Fiscal Years 2007 And 2008 [Member] Non-U.S. Examinations [Member]	Apr. 30, 2012 Fiscal Years 2009 And 2010 [Member] Non-U.S. Examinations [Member]
Taxes [Line Items]
Statutory federal income tax rate	35.00%
Tax impact of final settlement with IRS		$ 32.8
Estimated potential decrease in underlying unrecognized tax benefits, minimum	35
Estimated potential decrease in underlying unrecognized tax benefits, maximum	87
Decrease in unrecognized tax benefits resulting from settlement with taxing authorities	27.0	35.9	35.1
Income tax examination years		IRS for its audits of fiscal years 2006 through 2009
Cash payments as a result of settlement				$ 5.1	$ 14.6