Stock-Based Compensation

6 Months Ended

Nov. 30, 2015

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

STOCK-BASED COMPENSATION

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



	Three months ended November 30,				Six months ended November 30,
	2015		2014		2015		2014
Stock option expense	$	3.8	$	3.8	$	4.4	$	4.6
Restricted stock unit expense	0.7		0.6		1.4		1.3
Management stock purchase plan	0.6		0.6		0.6		0.6
Employee stock purchase plan	0.0		0.1		0.1		0.1
Total stock-based compensation expense	$	5.1	$	5.1	$	6.5	$	6.6

During the three month periods ended November 30, 2015 and 2014, respectively, approximately 0.2 million and 0.1 million shares of Common Stock were issued by the Corporation pursuant to its stock-based compensation plans. For the six month periods ended November 30, 2015 and 2014, respectively, approximately 1.2 million and 0.5 million shares of Common Stock were issued by the Corporation pursuant to its stock-based compensation plans.

For the three and six month periods ended November 30, 2014, total stock-based compensation expense included $0.6 and $0.6, respectively, of expenses recognized in discontinued operations.