Schedule of Share-based Compensation, Stock Options, Activity (Details) (USD $)	6 Months Ended
	Oct. 31, 2013
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 1	$ 3,930,818
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 2	1.33
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 3	1,055,000
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 4	1.67
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 5	(231,655)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 6	0.47
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 7	(18,604)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 8	1.86
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 9	(40,000)
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 10	0.47
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 11	4,695,559
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 12	1.45
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 13	2,682,368
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 14	1.14
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 15	2,677,887
Common Stock Schedule Of Share-based Compensation, Stock Options, Activity 16	$ 1.00