Stock-Based Compensation (Summary Of Nonvested Shares) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Apr. 30, 2012
Stock-Based Compensation [Abstract]
Shares, Outstanding, beginning of the year	1,150
Shares, Granted	787
Shares, Released	(522)
Shares, Forfeited	(180)
Shares, Outstanding, end of the year	1,235
Weighted-Average Grant Date Fair Value, Outstanding, beginning of the year	$ 15.35
Weighted-Average Grant Date Fair Value, Granted	$ 16.28
Weighted-Average Grant Date Fair Value, Released	$ 17.22
Weighted-Average Grant Date Fair Value, Forfeited	$ 15.46
Weighted-Average Grant Date Fair Value, Outstanding, end of the year	$ 15.12