Stock-Based Compensation

6 Months Ended

Nov. 30, 2020

Share-based Payment Arrangement [Abstract]

Stock-Based Compensation

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				Six months ended
	November 30,		November 30,		November 30,		November 30,
	2020		2019		2020		2019
Stock option expense	$	2.5	$	0.4	$	2.8	$	1.0
Restricted stock unit expense		0.5		0.4		0.7		1.2
Management stock purchase plan		0.0		0.0		0.0		0.0
Employee stock purchase plan		0.0		0.1		0.1		0.2
Total stock-based compensation expense	$	3.0	$	0.9	$	3.6	$	2.4

On October 1, 2020, the Company made an additional stock option grant to employees as a non-cash incentive.

The following table sets forth Common Stock issued pursuant to stock-based compensation plans for the periods indicated:

	Three months ended		Six months ended
	November 30,	November 30,	November 30,	November 30,
	2020	2019	2020	2019
Common Stock issued pursuant to stock-based compensation plans (in millions)	0.1	0.1	0.1	0.1