v2.3.0.11
Equity Compensation Plans (Narrative) (Details) (USD $)
3 Months Ended
Aug. 31, 2011
years
Aug. 31, 2010
Compensation expense $ 600,000 $ 675,000
Weighted-average fair value of stock options granted $ 8.66  
Warrant life, years 5  
Warrants outstanding 6,750  
Employee stock purchases discount 5.00%  
Employee And Director Stock Option [Member]
   
Stock options grant period, years 5  
Non-Qualified Options [Member]
   
Stock options grant period, years 10