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Convertible Instruments - Additional Information (Detail) (USD $)
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12 Months Ended | 12 Months Ended | 12 Months Ended | ||||||||||||||
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May 31, 2014
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May 31, 2013
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May 31, 2014
Investor
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May 31, 2014
Minimum
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May 31, 2013
Minimum
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May 31, 2014
Minimum
Investor
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May 31, 2014
Maximum
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May 31, 2013
Maximum
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May 31, 2014
Maximum
Investor
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May 31, 2014
Convertible Note Four
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May 31, 2014
Convertible Note One
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May 31, 2014
Convertible Note Two
Note
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May 31, 2014
One year convertible note
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May 31, 2010
Series B Convertible Preferred Stock
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May 31, 2014
Series B Convertible Preferred Stock
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May 31, 2010
Common Stock
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Apr. 30, 2010
Common Stock
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| Class of Stock [Line Items] | |||||||||||||||||
| Preferred Stock, Shares issued | 95,100 | 95,100 | 400,000 | ||||||||||||||
| Preferred Stock, Share issuance price | $ 0.40 | $ 0.56 | $ 0.67 | $ 0.89 | $ 5.00 | ||||||||||||
| Cash proceeds | $ 2,009,000 | ||||||||||||||||
| Preferred stock shares outstanding | 95,100 | 95,100 | 95,100 | ||||||||||||||
| Number of common shares issued upon conversion of preferred stock | 10 | ||||||||||||||||
| Convertible note conversion price per share | $ 0.75 | $ 0.75 | $ 0.65 | $ 0.50 | |||||||||||||
| Common stock shares authorized for issuance | 100,000,000 | 100,000,000 | 100,000,000 | ||||||||||||||
| Constructive dividend to Preferred stock holders | 6,000,000 | ||||||||||||||||
| Liquidation preference on common shares | $ 5.00 | ||||||||||||||||
| Dividends are payable to preferred stock holders | $ 0.25 | ||||||||||||||||
| Face amount of notes | 1,200,000 | 6,588,250 | |||||||||||||||
| Convertible note, principal amount | 4,271,250 | ||||||||||||||||
| Principal amount of notes | 2,450,000 | 567,000 | 1,120,000 | 1,330,000 | 250,000 | ||||||||||||
| Common stock issued upon conversion of notes | 1,493,333 | 2,046,148 | |||||||||||||||
| Number of notes converted | 1 | ||||||||||||||||
| Convertible notes term | 3 years | 6 months | |||||||||||||||
| Warrants to purchase shares of common stock | 292,307 | ||||||||||||||||
| Warrants exercise price per share | 0.50 | 0.50 | 2.00 | 0.75 | |||||||||||||
| Exercisable warrants, expire period | 5 years | ||||||||||||||||
| Interest expense associated with conversion inducement | 193,160 | 193,000 | |||||||||||||||
| Payments on convertible notes payable | 500,000 | 250,000 | |||||||||||||||
| Earliest date for repayment of principal on remaining notes | Oct. 01, 2015 | ||||||||||||||||
| Latest date for repayment of principal on remaining notes | Mar. 06, 2016 | ||||||||||||||||
| Interest rate on convertible notes | 5.00% | 10.00% | |||||||||||||||
| Interest on convertible notes payment start date | Apr. 01, 2013 | ||||||||||||||||
| Common stock warrant term | 2 years | 3 years | |||||||||||||||
| Warrants to purchase common shares, shares | 9,451,056 | ||||||||||||||||
| Warrants issued to investors | 923,072 | ||||||||||||||||
| Amortization expense | $ 3,807,000 | $ 1,704,000 | |||||||||||||||