Stock-Based Compensation

3 Months Ended

Aug. 31, 2011

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

10. Stock-Based Compensation

The following table summarizes stock-based compensation included in Selling, general and administrative expenses for the periods indicated:

	Three months ended August 31,
	2011		2010
Stock option expense	$	1.5	$	3.8
Restricted stock unit expense		0.7		1.4
Management stock purchase plan expense		0.0		0.0
Employee stock purchase plan expense		0.0		0.1
Total stock-based compensation expense	$	2.2	$	5.3

During each of the three months ended August 31, 2011 and 2010, shares of Common Stock issued by the Corporation pursuant to its stock-based compensation plans were not material.