v2.4.0.6
Earnings Per Share - Additional Information (Detail)
In Millions, unless otherwise specified
12 Months Ended
May 31, 2012
May 31, 2011
May 31, 2010
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive options not included in the computation of diluted earnings per share 0.1 0.2 0.2