Taxes (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011	May 31, 2010
Income Tax And Non Income Tax Disclosure [Text Block]
Deferred Tax Liabilities, Undistributed Foreign Earnings	$ 78.6
Deferred Tax Assets, Net	94.1	113.7
Deferred Tax Assets, Net of Valuation Allowance, Current	79.2	71.4
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent	14.9	42.3
Deferred Tax Valuation Allowance Decreased	2.5	2.4
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	116.3
Unrecognized Tax Benefits	35.5	38.7	30.8	30.6
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	6.5	7.1	5.9
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	21.8	18.1	19.2
Recognized Tax Expense	0.5	2.4	1.0
Unrecognized Tax Benefits, Period Increase (Decrease)	3.2	7.9
Sales and Excise Tax Payable	19.7
Sales Tax Settlement Payments	$ 15.3