Stock-Based Compensation (Tables)

3 Months Ended

Aug. 31, 2012

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

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

	Three months ended
	August 31, 2012		August 31, 2011
Stock option expense	$	1.0	$	1.5
Restricted stock unit expense		0.9		0.7
Management stock purchase plan		0.0		0.0
Employee stock purchase plan		0.1		0.0
Total stock-based compensation expense	$	2.0	$	2.2