Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
May 31, 2013	May 31, 2012	May 31, 2011
Income Tax Disclosure [Abstract]
Income taxes paid	$ 122.2	$ 160.8	$ 105.8
Cash repatriated from foreign subsidiaries		110
Cash repatriated from foreign subsidiaries, income tax expense		8.9
Undistributed earnings of foreign subsidiaries	194.0	140.7	222.0
Unrecognized tax benefits that would impact effective tax rates if recognized	10.9	9.0
Unrecognized tax benefits, interest and penalties accrual	1.1	2.0
Unrecognized tax benefits period increase (decrease)	(29.2)	(55.0)	6.4
Unrecognized tax benefits, decrease in accrued interest	0.9	7.1	6.6
Unrecognized tax benefits could decrease by approximately	$ 1.4

Cash Repatriated From Foreign Subsidiaries

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Cash Repatriated From Foreign Subsidiaries, Income Tax Expense

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Amount of deferred tax liability attributable to taxable temporary differences from undistributed earnings of subsidiaries and other recognized entities not within the country of domicile of the entity.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

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The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

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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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This element represents interest expense 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.

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The net amount of all increases and decreases in unrecognized tax benefits for the period.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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