INCOME TAXES - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Income Taxes [Line Items]
Effective income tax rate	30.70%	40.00%	29.60%	30.70%
Income tax examination years			During the nine months ended February 29, 2012 we settled the U.S. federal income tax examination for fiscal years 2007 and 2008.
Unrecognized tax benefits, reduction resulting from settlement of U.S. federal income tax examination			$ 1.4
Tax assessments from non-U.S. jurisdictions, possible additional payments upon final resolution			1.2
Unrecognized tax benefits	4.3		4.3
Unrecognized tax benefits which, if recognized, could affect the effective tax rate	3.4		3.4
Accrued interest and penalties related to unrecognized tax benefits	$ 1.6		$ 1.6