Stock Compensation Information (Summary Of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended		12 Months Ended
	Jan. 31, 2013		Apr. 30, 2012	Jan. 31, 2013
Stock Compensation Information [Abstract]
Shares, Outstanding at April 30, 2012	2,632,115
Shares, Granted	398,500
Shares, Cancelled or expired	(673,145)
Shares, Outstanding at January 31, 2013	2,357,470		2,632,115
Weighted average exercise price, Outstanding at April 30, 2012	$ 3.18
Weighted average exercise price, granted	$ 1.27
Weighted average exercise price, canceled or expired	$ 2.66
Weighted average exercise price, Outstanding at January 31, 2013	$ 3.00		$ 3.18
Weighted average remaining contractual term (in years), Outstanding April 30, 2012	6 years 10 months 10 days		7 years 2 months 27 days
Aggregate intrinsic value, Outstanding at April 30, 2012	$ 4,449	[1]		$ 23,557	[1]
Weighted average remaining contractual term (in years), Outstanding at January 31, 2013	6 years 10 months 10 days		7 years 2 months 27 days

[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.