Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summarizes Fortress warrant activities (Detail)

v3.7.0.1
Stockholders' Equity - Summarizes Fortress warrant activities (Detail) - Warrant [Member] - USD ($)
$ / shares in Units, $ in Thousands
 6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Subsidiary or Equity Method Investee [Line Items]    
Number of shares, Outstanding 2,263,453  
Number of shares, Granted 608,505  
Forfeited (123,007)  
Number of shares, Outstanding 2,748,951 2,263,453
Number of shares, Exercisable 768,951  
Weighted average exercise price, Outstanding $ 3.62  
Weighted average exercise price, Granted 3.61  
Weighted average exercise price, Forfeited 8.39  
Weighted average exercise price, Outstanding $ 3.4 $ 3.62
Total weighted average instrinsic value, Outstanding $ 940,203 $ 79,800
Weighted average exercise price, Exercisable $ 4.37  
Total weighted average instrinsic value, Outstanding $ 79,800  
Total weighted average intrinsic value, Granted 518,724  
Total weighted average instrinsic value, Forfeited 0  
Total weighted average intrinsic value, Exercisable $ 765,203  
Weighted average remaining contractual life, Granted (years) 4 years 10 months 10 days  
Weighted average remaining contractual life, Exercisable (years) 3 years 9 months  
Weighted average remaining contractual life, Forfeited (years) 0 years  
Weighted average remaining contractual life (years), Outstanding 3 years 9 months 7 days 4 years 8 months 26 days