Stock-Based Compensation (Summary Of Stock Options) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2017 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, beginning of the year | shares	1,976
Shares, Granted | shares	23
Option exercises, shares | shares	(162)
Shares, Forfeited or expired | shares	(135)
Shares, Outstanding, end of the year | shares	1,702
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	$ 18.76
Weighted-Average Exercise Price, Granted (in usd per share) | $ / shares	20.29
Weighted-Average Exercise Price, Exercised (in usd per share) | $ / shares	16.03
Weighted-Average Exercise Price, Forfeited or expired (in usd per share) | $ / shares	31.98
Weighted-Average Exercise Price, Outstanding, end of the year (in usd per share) | $ / shares	$ 17.99
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Shares, Exercisable, end of the year | shares	1,675
Shares, Exercisable and expected to vest | shares	1,699
Weighted-Average Exercise Price, Exercisable, end of the year | $ / shares	$ 17.93
Weighted-Average Exercise Price, Exercisable and expected to vest | $ / shares	$ 17.99
Weighted-Average Remaining Contractual Term, Outstanding, end of the year	4 years
Weighted-Average Remaining Contractual Term, Exercisable, end of the year	4 years
Weighted-Average Remaining Contractual Term, Exercisable and expected to vest, years	4 years
Aggregate Intrinsic Value, Outstanding, end of the year | $	$ 11,651
Aggregate Intrinsic Value, Exercisable, end of the year | $	11,549
Aggregate Intrinsic Value, Exercisable and expected to vest | $	$ 11,640