Share-Based Payments (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Jul. 31, 2014	Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding, Beginning Balance	23,351,037
Shares, Granted	215,000
Shares, Forfeited	(11,250)
Shares, Expired	(172,500)
Shares, Outstanding, Ending Balance	23,382,287	23,351,037
Shares, Vested and expected to vest	23,382,287
Shares, Exercisable	14,695,827
Weighted Average Exercise Price, Outstanding, Beginning Balance	$ 1.01
Weighted Average Exercise Price, Granted	$ 1.01
Weighted Average Exercise Price, Forfeited	$ 0.49
Weighted Average Exercise Price, Expired	$ 1.12
Weighted Average Exercise Price, Outstanding, Ending Balance	$ 1.01	$ 1.01
Weighted Average Exercise Price, Vested and expected to vest	$ 1.01
Weighted Average Exercise Price, Exercisable	$ 0.88
Weighted Average Remaining Contractual Term, Outstanding (in years)	7 years 3 months 18 days	7 years 6 months
Weighted Average Remaining Contractual Life (Years), Vested and expected to vest	7 years 3 months 18 days
Weighted Average Remaining Contractual Life (Years), Exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding, Beginning Balance	$ 985,000
Aggregate Intrinsic Value, Outstanding, Ending Balance	739,000	985,000
Aggregate Intrinsic Value, Vested and expected to vest	739,000
Aggregate Intrinsic Value, Exercisable	$ 701,000
Non-Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding, Beginning Balance	765,000
Shares, Granted	80,000
Shares, Forfeited	0
Shares, Expired	(150,000)
Shares, Outstanding, Ending Balance	695,000
Shares, Vested and expected to vest	695,000
Shares, Exercisable	396,042
Directors and Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Outstanding, Beginning Balance	22,586,037
Shares, Granted	135,000
Shares, Forfeited	(11,250)
Shares, Expired	(22,500)
Shares, Outstanding, Ending Balance	22,687,287
Shares, Vested and expected to vest	22,687,287
Shares, Exercisable	14,299,785