EMPLOYEE BENEFIT PLANS (Detail) - Schedule Of Amounts Recognized In Balance Sheet (USD $) In Millions, unless otherwise specified	May 31, 2012	May 31, 2011
Pension Plans, Defined Benefit [Member]
Non-current liabilities	$ 36.4	$ 27.2
Net underfunded balance	36.4	27.2
Other Postretirement Benefit Plans, Defined Benefit [Member]
Current liabilities	3.4	2.8
Non-current liabilities	36.2	35.5
Net underfunded balance	$ 39.6	$ 38.3