Quarterly report pursuant to Section 13 or 15(d)

Assumptions used in Estimating Fair Value of Convertible Note Redemption Provision Derivative Liability (Detail)

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Assumptions used in Estimating Fair Value of Convertible Note Redemption Provision Derivative Liability (Detail)
 1 Months Ended 3 Months Ended
Jan. 30, 2019
yr
$ / shares
Nov. 15, 2018
yr
$ / shares
Nov. 30, 2019
yr
$ / shares
Fair value of underlying stock      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, price per share | $ / shares $ 0.49 $ 0.57  
Fair value of underlying stock | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, price per share | $ / shares     $ 0.28
Fair value of underlying stock | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, price per share | $ / shares     $ 0.28
Risk free rate      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input 2.52 2.78  
Risk free rate | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     1.63
Risk free rate | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     1.60
Expected Term (In Years)      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, expected term 2 years 1 year 7 months 9 days  
Expected Term (In Years) | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, expected term     6 months 25 days
Expected Term (In Years) | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, expected term     1 year 2 months 1 day
Stock price volatility      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input 61 58.8  
Stock price volatility | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     66.3
Stock price volatility | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     64.1
Expected dividend yield      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, dividend yield 0.00% 0.00%  
Expected dividend yield | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, dividend yield     0.00%
Expected dividend yield | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded derivative liability, dividend yield     0.00%
Discount factor      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input 85 85  
Discount factor | June Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     85
Discount factor | January Note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Embedded Derivative Liability, Measurement Input     85