XML 48 R49.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended 9 Months Ended
Jan. 31, 2020
Jan. 31, 2019
Jan. 31, 2020
Jan. 31, 2019
Stock-based Compensation [Abstract]        
Share-based compensation expense $ 5.4 $ 6.1 $ 15.7 $ 15.0
Restricted Stock [Member]        
Restricted Stock Awards Granted to Employees [Abstract]        
Awards granted (in shares)     738 406
Weighted average fair value of grant (in dollars per share)     $ 44.85 $ 63.09
Performance-based Stock Awards [Member]        
Stock-based Compensation [Abstract]        
Period for achievement of performance-based targets     3 years