XML 29 R27.htm IDEA: XBRL DOCUMENT  v2.3.0.11
Stock-Based Compensation (Tables)
3 Months Ended
Aug. 31, 2011
Market-Based Restricted Common Shares [Member]
 
Assumption To Value Stock Options

Dividend yield

     2.30

Expected volatility

     52.60

Risk-free interest rate

     1.76
Non-Qualified Stock Options [Member]
 
Assumption To Value Stock Options

Dividend yield

     2.72

Expected volatility

     51.72

Risk-free interest rate

     2.13

Expected term (years)

     6.0