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Share-Based Payments (Details 4)
3 Months Ended 12 Months Ended
Jul. 31, 2014
Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Dividend yield 0.00% 0.00%
Minimum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term in years 1 year 8 months 12 days 1 year 10 months 24 days
Risk-free interest rates 0.57% 0.40%
Volatility 92.90% 95.00%
Maximum [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected term in years 3 years 6 months 3 years 8 months 12 days
Risk-free interest rates 1.23% 1.17%
Volatility 107.20% 113.00%