Annual report pursuant to Section 13 and 15(d)

Weighted Average Assumptions to Value Investor Warrants (Detail)

v3.20.2
Weighted Average Assumptions to Value Investor Warrants (Detail) - $ / shares
 12 Months Ended
Nov. 28, 2018
Sep. 15, 2016
May 31, 2019
Nov. 30, 2018
Expected Term (In Years)        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Expected term   5 years 2 years 3 months 14 days  
Risk Free Interest Rate        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Risk-free interest rate   1.20% 1.94%  
Grant Date Fair Value        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Grant-date fair value   $ 0.78 $ 0.39  
Detachable Common Stock Warrants | Stock Price Volatility        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Stock price volatility       69.80%
Detachable Common Stock Warrants | Expected Term (In Years)        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Expected term 5 years      
Detachable Common Stock Warrants | Short-Term Convertible Notes | Expected Dividend Yield        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Expected dividend yield       0.00%
Detachable Common Stock Warrants | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Expected Dividend Yield        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Expected dividend yield     0.00%  
Detachable Common Stock Warrants | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Expected Term (In Years)        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Expected term     5 years  
Detachable Common Stock Warrants | Minimum | Risk Free Interest Rate        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Risk-free interest rate 1.77%      
Detachable Common Stock Warrants | Minimum | Grant Date Fair Value        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Grant-date fair value $ 0.30      
Detachable Common Stock Warrants | Minimum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Expected Dividend Yield        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Stock price volatility     55.80%  
Detachable Common Stock Warrants | Minimum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Risk Free Interest Rate        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Risk-free interest rate     2.48%  
Detachable Common Stock Warrants | Minimum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Grant Date Fair Value        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Grant-date fair value     $ 0.30  
Detachable Common Stock Warrants | Maximum | Risk Free Interest Rate        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Risk-free interest rate 1.93%      
Detachable Common Stock Warrants | Maximum | Grant Date Fair Value        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Grant-date fair value $ 0.39      
Detachable Common Stock Warrants | Maximum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Expected Dividend Yield        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Stock price volatility     55.88%  
Detachable Common Stock Warrants | Maximum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Risk Free Interest Rate        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Risk-free interest rate     2.56%  
Detachable Common Stock Warrants | Maximum | Two Thousand And Nineteen Short Term Convertible Notes [Member] | Grant Date Fair Value        
Fair Value Measurement Inputs and Valuation Techniques [Line Items]        
Grant-date fair value     $ 0.38