Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
May 31, 2012	May 31, 2012	May 31, 2011	May 31, 2010
Income Tax Disclosure [Abstract]
Income taxes paid		$ 160.8	$ 105.8	$ 103.8
Repatriated earnings	110
Additional tax provision recognized as a result of repatriated earnings	7.4
Undistributed earnings of foreign subsidiaries	140.7	140.7	222.0	198.3
Unrecognized tax benefits that would impact effective tax rates if recognized	9.0	9.0	18.8
Unrecognized tax benefits, interest and penalties accrual	2.0	2.0	9.1
Unrecognized tax benefits period increase (decrease)		(55.0)	6.4	0.9
Unrecognized tax benefits, increase (decrease) in accrued interest		(7.1)	(6.6)	(0.1)
Unrecognized tax benefits could decrease by approximately	$ 2.4	$ 2.4

Cash Repatriated From Foreign Subsidiaries

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The amount as of the balance sheet date of the estimated future tax effects attributable to undistributed earnings of subsidiaries and other recognized entities in countries outside the country of domicile which will increase future taxable income when such earnings are distributed into the country of domicile.

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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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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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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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