Stock-Based Compensation (Summary Of Stock Options) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, beginning of the year | shares	2,613
Shares, Granted | shares	112
Option exercises, shares | shares	(707)
Shares, Forfeited or expired | shares	(42)
Shares, Outstanding, end of the year | shares	1,976
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-Average Exercise Price, Outstanding, beginning of the year (in usd per share) | $ / shares	$ 17.71
Weighted-Average Exercise Price, Granted (in usd per share) | $ / shares	34.73
Weighted-Average Exercise Price, Exercised (in usd per share) | $ / shares	16.85
Weighted-Average Exercise Price, Forfeited or expired (in usd per share) | $ / shares	27.15
Weighted-Average Exercise Price, Outstanding, end of the year (in usd per share) | $ / shares	$ 18.76
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Shares, Exercisable, end of the year | shares	1,871
Shares, Exercisable and expected to vest | shares	1,961
Weighted-Average Exercise Price, Exercisable, end of the year | $ / shares	$ 17.85
Weighted-Average Exercise Price, Exercisable and expected to vest | $ / shares	$ 18.64
Weighted-Average Remaining Contractual Term, Outstanding, end of the year	5 years
Weighted-Average Remaining Contractual Term, Exercisable, end of the year	5 years
Weighted-Average Remaining Contractual Term, Exercisable and expected to vest, years	5 years
Aggregate Intrinsic Value, Outstanding, end of the year | $	$ 4,812
Aggregate Intrinsic Value, Exercisable, end of the year | $	4,812
Aggregate Intrinsic Value, Exercisable and expected to vest | $	$ 4,812