XML 36 R24.htm IDEA: XBRL DOCUMENT v3.21.1
Stock-Based Compensation (Tables)
3 Months Ended
Mar. 31, 2021
Share-based Payment Arrangement [Abstract]  
Schedule of stock-based compensation expense
Stock-based compensation expense for the three months ended March 31, 2021 and 2020 is shown in the table below (in millions):
Three Months Ended March 31,
20212020
Stock options$0.6 $0.6 
Time-based restricted share units1.8 0.9 
Performance-based restricted share units0.6 0.9 
Employee stock purchase plan0.1 0.1 
Total stock-based compensation$3.1 $2.5