Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plan - Summary of Assumptions Used to Estimate the Fair Value of Stock Options Granted (Detail)

v3.8.0.1
Stock Compensation Plan - Summary of Assumptions Used to Estimate the Fair Value of Stock Options Granted (Detail)
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]    
Expected life of options 10 years 10 years
Expected dividend yield 0.00% 0.00%
Weighted-average expected volatility 143.00%  
Weighted-average risk-free interest rate 2.15%  
Weighted-average expected volatility, minimum   142.00%
Weighted-average expected volatility, maximum   147.00%
Weighted-average risk-free interest rate, minimum   1.59%
Weighted-average risk-free interest rate, maximum   2.40%