Description of the Business, Basis of Presentation and Summary of Significant Accounting Policies (Tables)

12 Months Ended

May 31, 2013

Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The table set forth below provides the estimated fair value of options granted during fiscal years 2013, 2012 and 2011 and the significant weighted average assumptions used in determining the fair value for options granted by the Company under the Black-Scholes option pricing model.

	2013			2012			2011
Estimated fair value of stock options granted	$	9.77		$	9.30		$	8.15
Assumptions:
Expected dividend yield		1.6	%		1.4	%		1.3	%
Expected stock price volatility		37.5	%		36.7	%		37.3	%
Risk-free interest rate		0.9	%		1.6	%		2.0	%
Expected life of options		6 years			7 years			6 years