Stock-Based Compensation (Summary Of Stock Options) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 30, 2012 Y
Stock-Based Compensation [Abstract]
Shares, Outstanding, beginning of the year	10,790
Shares, Granted	2,658
Shares, Exercised	(658)
Shares, Forfeited or expired	(5,482)
Shares, Outstanding, end of the year	7,308
Shares, Exercisable, end of the year	4,114
Shares, Exercisable and expected to vest	6,950
Weighted-Average Exercise Price, Outstanding, beginning of the year	$ 18.64
Weighted-Average Exercise Price, Granted	$ 16.46
Weighted-Average Exercise Price, Exercised	$ 15.32
Weighted-Average Exercise Price, Forfeited or expired	$ 18.81
Weighted-Average Exercise Price, Outstanding, end of the year	$ 18.02
Weighted-Average Exercise Price, Exercisable, end of the year	$ 19.86
Weighted-Average Exercise Price, Exercisable and expected to vest	$ 18.15
Weighted-Average Remaining Contractual Term, Outstanding, end of the year	6
Weighted-Average Remaining Contractual Term, Exercisable, end of the year	4
Weighted-Average Remaining Contractual Term, Exercisable and expected to vest, years	6
Aggregate Intrinsic Value, Outstanding, end of the year	$ 2,117
Aggregate Intrinsic Value, Exercisable, end of the year	751
Aggregate Intrinsic Value, Exercisable and expected to vest	$ 1,941