XML 70 R54.htm IDEA: XBRL DOCUMENT v3.19.2
Stock-Based Compensation (Narrative) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Apr. 30, 2017
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Stock-based compensation expenses $ 23.8 $ 22.0 $ 19.3
Tax benefit of stock-based compensation 6.1 6.9 6.0
Tax benefit from exercise of stock options $ 3.4 $ 15.3 $ 5.9
Shares reserved for future awards under stock-based compensation plans 13.9    
Maximum contractual term 10 years    
Stock Options For Management And Director      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Weighted average fair value (in dollars per share)   $ 5.02 $ 3.31
2003 Long-Term Executive Compensation Plan      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Vesting period (in years), minimum 3 years    
Nonvested Shares      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Fair value of shares vesting during period $ 17.9 $ 22.6 $ 20.3
Unrecognized compensation cost $ 25.6    
Weighted-average period of recognition (years) 2 years    
Stock Options      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Unrecognized compensation cost $ 0.6    
Weighted-average period of recognition (years) 1 year    
Intrinsic value of options exercised $ 0.4 $ 18.9 $ 1.0
Minimum | 2003 Long-Term Executive Compensation Plan      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Vesting period (in years), minimum 3 years    
Percentage of performance-based share units that ultimately vest 0.00%    
Maximum | 2003 Long-Term Executive Compensation Plan      
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]      
Percentage of performance-based share units that ultimately vest 20000.00%