Schedule of Share-based Compensation, Stock Options, Activity (Details) (USD $)	12 Months Ended
	Apr. 30, 2014
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 1	$ 3,925,979
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 2	1.15
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 3	540,000
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 4	1.38
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 5	(220,649)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 6	0.96
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 7	(301,312)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 8	1.03
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 9	(13,200)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 10	1.33
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 11	3,930,818
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 12	1.33
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 13	1,905,000
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 14	1.49
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 15	(1,365,571)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 16	0.56
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 17	(716,708)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 18	1.76
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 19	(48,000)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 20	0.47
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 21	3,705,539
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 22	1.62
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 23	1,767,621
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 24	1.60
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 25	2,677,887
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 26	$ 1.00