Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Warrants (Details)

v3.20.1
Stockholders' Equity - Warrants (Details) - Warrants (Note 6) - $ / shares
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Warrants, Outstanding Beginning Balance 4,280,972 4,326,555  
Warrants, Exercised (73,525) (45,583)  
Warrants, Outstanding Ending Balance 4,207,447 4,280,972 4,326,555
Weighted Average Exercise Price, Nonvested Beginning Balance $ 6.69 $ 6.62  
Weighted Average Exercise Price Exercised 0 0  
Weighted Average Exercise Price, Nonvested Ending Balance $ 6.81 $ 6.69 $ 6.62
Weighted Average Remaining Contractual Life, Outstanding (in years) 1 year 3 months 2 years 3 months 29 days 3 years 8 months 1 day