General form of registration statement for all companies including face-amount certificate companies

Convertible Instruments - Weighted Average Assumptions to Value Investor Warrants (Detail)

v3.3.1.900
Convertible Instruments - Weighted Average Assumptions to Value Investor Warrants (Detail) - $ / shares
 6 Months Ended 12 Months Ended
Nov. 30, 2015
May. 31, 2015
May. 31, 2014
Detachable Common Stock Warrants      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected dividend yield 0.00% 0.00% 0.00%
Stock price volatility   88.79%  
Expected term 1 year 5 years  
Risk-free interest rate 0.33% 0.12%  
Grant-date fair value   $ 0.15  
Detachable Common Stock Warrants | Previously Reported      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Stock price volatility   80.68%  
Expected term   6 months  
Detachable Common Stock Warrants | Minimum      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Stock price volatility 64.56%   78.00%
Expected term     3 years
Risk-free interest rate   1.46% 0.64%
Grant-date fair value $ 0.15 $ 0.52 $ 0.66
Detachable Common Stock Warrants | Maximum      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Stock price volatility 69.30%   93.00%
Expected term     5 years
Risk-free interest rate   1.58% 1.42%
Grant-date fair value $ 0.18 $ 0.76 $ 0.72
Investor Warrants      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Expected dividend yield 0.00% 0.00%  
Stock price volatility 88.79% 88.79%  
Expected term 5 years 5 years  
Investor Warrants | Minimum      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Risk-free interest rate 146.00% 1.46%  
Grant-date fair value $ 0.52 $ 0.52  
Investor Warrants | Maximum      
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]      
Risk-free interest rate 158.00% 1.58%  
Grant-date fair value $ 0.76 $ 0.76