XML 129 R75.htm IDEA: XBRL DOCUMENT v3.8.0.1
Share-Based Payments (Details 2) - $ / shares
12 Months Ended
Apr. 30, 2018
Apr. 30, 2017
Apr. 30, 2016
Restricted Shares and Deferred Stock Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Beginning Balance, Restricted Shares and Deferred Stock Units and Performance Units 573,405    
Granted Restricted Shares and Deferred Stock Units and Performance Units 136,127 180,997 97,922
Converted Restricted Shares and Deferred Stock Units and Performance Units 73,701    
Vested Restricted Shares and Deferred Stock Units and Performance Units (161,581)    
Forfeited Restricted Shares and Deferred Stock Units and Performance Units (79,294)    
Ending Balance, Restricted Shares and Deferred Stock Units and Performance Units 542,358 573,405  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]      
Beginning Balance, Weighted Average Grant Date Fair Value (in dollars per share) $ 115.88    
Granted Weighted Average Grant Date Fair Value (in dollars per share) 126.80 $ 133.92 $ 113.57
Converted Weighted Average Grant Date Fair Value (in dollars per share) 126.80    
Vested Weighted Average Grant Date Fair Value (in dollars per share) 106.04    
Forfeited Weighted Average Grant Date Fair Value (in dollars per share) 120.27    
Ending Balance, Weighted Average Grant Date Fair Value (in dollars per share) $ 122.39 $ 115.88  
Performance Units [Member]      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]      
Beginning Balance, Restricted Shares and Deferred Stock Units and Performance Units 73,701    
Granted Restricted Shares and Deferred Stock Units and Performance Units 84,051 73,701 121,936
Converted Restricted Shares and Deferred Stock Units and Performance Units (73,701)    
Vested Restricted Shares and Deferred Stock Units and Performance Units 0    
Forfeited Restricted Shares and Deferred Stock Units and Performance Units 0    
Ending Balance, Restricted Shares and Deferred Stock Units and Performance Units 84,051 73,701  
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]      
Beginning Balance, Weighted Average Grant Date Fair Value (in dollars per share) $ 126.80    
Granted Weighted Average Grant Date Fair Value (in dollars per share) 103.86    
Converted Weighted Average Grant Date Fair Value (in dollars per share) 126.80    
Vested Weighted Average Grant Date Fair Value (in dollars per share) 0.00    
Forfeited Weighted Average Grant Date Fair Value (in dollars per share) 0.00    
Ending Balance, Weighted Average Grant Date Fair Value (in dollars per share) $ 103.86 $ 126.80