XML 67 R54.htm IDEA: XBRL DOCUMENT v3.8.0.1
Stock-Based Compensation (Schedule Of Stock Options Oustanding Activity) (Details)
12 Months Ended
Apr. 30, 2018
$ / shares
shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Options outstanding | shares 17,968
Options exercisable | shares 9,266
$22.77 - $23.96 [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Option price per share, lower range limit $ 22.77
Option price per share, upper range limit $ 23.96
Options outstanding | shares 6,800
Options outstanding remaining life 2 months 12 days
Options outstanding exercise price $ 23.09
Options exercisable | shares 6,800
Options exercisable exercise price $ 23.09
$29.92- $34.11 [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Option price per share, lower range limit 29.92
Option price per share, upper range limit 34.11
$57.11 [Member]  
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]  
Option price per share, lower range limit 57.11
Option price per share, upper range limit $ 57.11
Options outstanding | shares 11,168
Options outstanding remaining life 7 years 1 month 6 days
Options outstanding exercise price $ 57.11
Options exercisable | shares 2,466
Options exercisable exercise price $ 57.11