Stockholders' Equity (Tables)
   | 
9 Months Ended | 
Jan. 31, 2017  | 
| Schedule of Warrants Activity | 
 A summary of the Companys warrant activity during the nine months ended January 31, 2017 is presented below: 
  
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 Weighted 
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| 
   
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 Weighted 
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 Average 
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| 
   
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 Average 
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 Remaining 
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 Aggregate 
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| 
   
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 Number of 
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 Exercise 
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 Contractual 
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 Intrinsic 
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| 
 Warrants 
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 Shares 
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 Price 
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 Term 
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 Value 
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| 
 Balance outstanding, April 30, 2016 
 | 
   
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 1,993,023  
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 $ 
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 2.28  
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$ | 
 1,054,450 
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| 
 Granted 
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 62,500 
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 2.40 
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 78,125 
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| 
 Exercised 
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| 
 Forfeited 
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 (1,120,968  
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 ) 
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 1.92  
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| 
 Expired 
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| 
 Balance outstanding, January 31, 2017 
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 934,555  
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 $ 
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 2.88  
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 1.8 
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 | 
 $ 
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 1,132,575 
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| 
   
 | 
   
 | 
   
 | 
   
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 | 
   
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 | 
   
 | 
   
 | 
   
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| 
 Exercisable, January 31, 2017 
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 934,555  
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 | 
   
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 $ 
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 2.88  
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 1.8 
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 $ 
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 1,132,575 
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| Stock Incentive Plan and Stock Option Grants to Employees and Directors [Member] | 
 
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| Schedule of Assumptions Used In Valuing Stock Options | 
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   | 
 January 31, 
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 2017 
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| 
 Expected life (years) 
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 4-6.5 
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   | 
 
| 
 Expected volatility 
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 40-43 
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 % 
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| 
 Risk-free interest rate 
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   | 
   | 
   
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 0.00 
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 % 
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| 
 Dividend yield 
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   | 
   | 
   
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 n/a 
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| Schedule of Stock Option Activity | 
   
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 Weighted 
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 Average 
 | 
   
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| 
   
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 Average 
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 Remaining 
 | 
   
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 | 
 Aggregate 
 | 
   
 | 
 
| 
   
 | 
   
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 Number of 
 | 
   
 | 
   
 | 
 Exercise 
 | 
   
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 Contractual 
 | 
   
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 Intrinsic 
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| 
 Options 
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 Shares 
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 Price 
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 Term 
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 Value 
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| 
 Balance outstanding, April 30, 2016 
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 1,494,259  
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 $ 
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 2.76  
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 0.6 
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$
 | 
 2,020,711 
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| 
 Granted 
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 538,333  
 | 
   
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 | 
 $ 
 | 
 2.40  
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 4.5 
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 | 
   
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 694,390 
 | 
   
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| 
 Exercised 
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| 
 Forfeited 
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 (85,361  
 | 
 ) 
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 | 
 $ 
 | 
 3.72  
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 | 
 1.9 
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| 
 Expired 
 | 
   
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| 
 Balance outstanding, January 31, 2017 
 | 
   
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 | 
 1,947,231  
 | 
   
 | 
   
 | 
 $ 
 | 
 2.28  
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 | 
   
 | 
   
 | 
 3.09 
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 | 
 $ 
 | 
 2,715,101 
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| 
   
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| 
 Exercisable, January 31, 2017 
 | 
   
 | 
   
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 1,891,540  
 | 
   
 | 
   
 | 
 $ 
 | 
 2.28  
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 1.86 
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 | 
 $ 
 | 
 1,375,198 
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 | 
 
 
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| Stock Option Grants To Non Employees [Member] | 
 
 | 
| Schedule of Stock Option Activity | 
 A summary of the Company's stock option activity for non-employees during the nine months ended January 31, 2017, is presented below: 
  
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   | 
   
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 Weighted 
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 | 
   
 | 
 Average 
 | 
   
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| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 Average 
 | 
   
 | 
   
 | 
 Remaining 
 | 
   
 | 
   
 | 
 Aggregate 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 Number of 
 | 
   
 | 
   
 | 
 Exercise 
 | 
   
 | 
   
 | 
 Contractual 
 | 
   
 | 
   
 | 
 Intrinsic 
 | 
   
 | 
 
| 
 Options 
 | 
   
 | 
 Shares 
 | 
   
 | 
   
 | 
 Price 
 | 
   
 | 
   
 | 
 Term 
 | 
   
 | 
   
 | 
 Value 
 | 
   
 | 
 
| 
 Balance outstanding, April 30, 2016 
 | 
   
 | 
   
 | 
 16,250  
 | 
   
 | 
   
 | 
 $ 
 | 
 3.48  
 | 
   
 | 
   
 | 
   
 | 
 0.20 
 | 
   
 | 
   
 | 
 $ 
 | 
 8,550 
 | 
   
 | 
 
| 
 Granted 
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
 
| 
 Exercised 
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
 
| 
 Forfeited 
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
 
| 
 Expired 
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
   
 | 
   
 | 
  
 | 
   
 | 
 
| 
 Balance outstanding, January 31, 2017 
 | 
   
 | 
   
 | 
 16,250  
 | 
   
 | 
   
 | 
 $ 
 | 
 3.48  
 | 
   
 | 
   
 | 
   
 | 
 0.20 
 | 
   
 | 
   
 | 
 $  
 | 
 8,550 
 | 
   
 | 
 
| 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
   
 | 
 
| 
 Exercisable, January 31, 2017 
 | 
   
 | 
   
 | 
 16,250  
 | 
   
 | 
   
 | 
 $ 
 | 
 3.48  
 | 
   
 | 
   
 | 
   
 | 
 0.20 
 | 
   
 | 
   
 | 
 $  
 | 
 8,550 
 | 
   
 | 
 
 
 |