Share-Based Payments (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Oct. 31, 2012
Shares, Outstanding, May 1, 2012	14,866,038
Shares, Granted	291,250
Shares, Exercised	0
Shares, Forfeited	0
Shares, Expired	(513,333)
Shares, Change in employee status	0
Shares, Outstanding, October 31, 2012	14,643,955
Shares, Vested and expected to vest as of October 31, 2012	14,636,455
Shares, Exercisable as of October 31, 2012	9,607,579
Weighted Average Exercise Price, Outstanding, May 1, 2012	$ 0.88
Weighted Average Exercise Price, Granted	$ 0.54
Weighted Average Exercise Price, Exercised	$ 0
Weighted Average Exercise Price, Forfeited	$ 0
Weighted Average Exercise Price, Expired	$ 0.76
Weighted Average Exercise Price, Change in employee status	$ 0
Weighted Average Exercise Price, Outstanding, October 31, 2012	$ 0.87
Weighted Average Exercise Price, Vested and expected to vest as of October 31, 2012	$ 0.87
Weighted Average Exercise Price, Exercisable as of October 31, 2012	$ 0.88
Weighted Average Remaining Contractual Term, Outstanding, May 1, 2012	7 years 7 months 6 days
Weighted Average Remaining Contractual Term, Outstanding, October 31, 2012	7 years 4 months 24 days
Weighted Average Remaining Contractual Term, Vested and expected to vest as of October 31, 2012	7 years 1 month 6 days
Weighted Average Remaining Contractual Term, Exercisable as of October 31, 2012	7 years
Aggregate Intrinsic Value, Outstanding, May 1, 2012	$ 0
Aggregate Intrinsic Value, Granted	$ 5,000
Aggregate Intrinsic Value, Outstanding, October 31, 2012	5,000
Aggregate Intrinsic Value, Vested and expected to vest as of October 31, 2012	5,000
Aggregate Intrinsic Value, Exercisable as of October 31, 2012	$ 0
Non- Employees [Member]
Shares, Outstanding, May 1, 2012	1,410,000
Shares, Granted	40,000
Shares, Exercised	0
Shares, Forfeited	0
Shares, Expired	(500,000)
Shares, Change in employee status	0
Shares, Outstanding, October 31, 2012	950,000
Shares, Vested and expected to vest as of October 31, 2012	950,000
Shares, Exercisable as of October 31, 2012	832,709
Directors and Employees [Member]
Shares, Outstanding, May 1, 2012	13,456,038
Shares, Granted	251,250
Shares, Exercised	0
Shares, Forfeited	0
Shares, Expired	(13,333)
Shares, Change in employee status	0
Shares, Outstanding, October 31, 2012	13,693,955
Shares, Vested and expected to vest as of October 31, 2012	13,686,455
Shares, Exercisable as of October 31, 2012	8,774,870