Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Schedule of stock-based compensation expense

Stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 is shown in the table below (in millions):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Stock options	$	0.7	$	0.7	$	2.0	$	2.4
Time-based restricted share units	1.8		0.6		4.2		3.2
Performance-based restricted share units	0.8		1.4		2.5		3.1
Employee stock purchase plan	0.1		0.1		0.2		0.1
Total stock-based compensation	$	3.4	$	2.8	$	8.9	$	8.8