Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Summarizes Fortress warrant activities (Details)

v3.19.2
Stockholders' Equity - Summarizes Fortress warrant activities (Details) - Warrants to Purchase Common Stock [Member] - USD ($)
 6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Subsidiary or Equity Method Investee [Line Items]    
Number of shares, Outstanding 2,754,189  
Number of shares, Outstanding 2,754,189 2,754,189
Number of shares, Exercisable 849,189  
Weighted average exercise price, Outstanding $ 3.28  
Weighted average exercise price, Outstanding 3.28 $ 3.28
Weighted average exercise price, Exercisable $ 3.92  
Total intrinsic value, Outstanding $ 7,800 $ 7,800
Total intrinsic value, Exercisable $ 7,800  
Weighted average remaining contractual life (years), Outstanding 3 years 3 years 5 months 27 days
Weighted average remaining contractual life, Exercisable (years) 2 years 7 months 21 days