Stock Compensation Information (Summary Of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Jul. 31, 2013		Apr. 30, 2013
Stock Compensation Information [Abstract]
Shares, Outstanding at April 30, 2013	1,814,559
Shares, Granted	204,000
Shares, Exercised
Shares, Cancelled or expired	(323,706)
Shares, Outstanding at July 31, 2013	1,694,853		1,814,559
Weighted average exercise price, Outstanding at April 30, 2013	$ 2.83
Weighted average exercise price, granted	$ 1.12
Weighted average exercise price, exercised
Weighted average exercise price, canceled or expired	$ 2.44
Weighted average exercise price, Outstanding at July 31, 2013	$ 2.69		$ 2.83
Weighted average remaining contractual term (in years), Outstanding	6 years 10 months 13 days		6 years 11 months 1 day
Aggregate intrinsic value, Outstanding at April 30, 2013	$ 15,551	[1]
Aggregate intrinsic value, Outstanding at July 31, 2013	$ 87,649	[1]	$ 15,551	[1]

[1] Aggregate intrinsic value is defined as the difference between the current market value and the exercise price and is estimated using the closing price of the Company’s common stock on the last trading day of the periods ended as of the dates indicated.