Stock Compensation Information (Summary Of Non-Vested Stock Option Activity) (Details) (USD $)	6 Months Ended
	Oct. 31, 2012
Stock Compensation Information [Abstract]
Shares, Nonvested at April 30, 2012	1,005,036
Shares, Granted	384,500
Shares, Vested	(250,605)
Shares, Cancelled or expired	(233,743)
Shares, Nonvested at October 31, 2012	905,188
Weighted average grant date fair value, Nonvested at April 30, 2012	$ 1.61
Weighted average grant date fair value, Granted	$ 1.02
Weighted average grant date fair value, Vested	$ 1.59
Weighted average grant date fair value, Cancelled or expired	$ 1.51
Weighted average grant date fair value, Nonvested at October 31, 2012	$ 1.34