Stock-Based Compensation (Tables)

6 Months Ended

Nov. 30, 2011

Market-Based Restricted Common Shares [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Assumption To Value Stock Options

Dividend yield	2.3	%
Expected volatility	52.6	%
Risk-free interest rate	1.8	%

Non-Qualified Stock Options [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Assumption To Value Stock Options

Dividend yield	2.7	%
Expected volatility	51.7	%
Risk-free interest rate	1.9	%
Expected term (years)	6.0