Annual report pursuant to Section 13 and 15(d)

Assumptions used in Estimating Fair Value of Warrant Derivative Liability (Detail)

v3.7.0.1
Assumptions used in Estimating Fair Value of Warrant Derivative Liability (Detail) - $ / shares
12 Months Ended
Sep. 15, 2016
May 31, 2017
Derivative [Line Items]    
Fair value of underlying stock $ 0.78 $ 0.60
Risk free rate 1.20% 1.71%
Expected term (in years) 5 years 4 years 3 months 15 days
Stock price volatility 106.00% 94.00%
Expected dividend yield 0.00% 0.00%
Probability of Fundamental Transaction 50.00% 50.00%
Probability of holder requesting cash payment 50.00% 50.00%