Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Summary of stock option activity (Details)

v3.20.2
Stock-Based Compensation - Summary of stock option activity (Details) - Stock Option [Member] - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2020
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options, Beginning Balance 2,502,012 938,982  
Options, Granted 0 1,725,000  
Options, Exercised 0 0  
Options, Expired 0 (94,738)  
Options, Forfeited (29,650) (67,232)  
Options, Ending Balance 2,472,362 2,502,012 938,982
Options, Exercisable 628,408    
Weighted Average Exercise Price, Beginning Balance $ 3.62 $ 15.18  
Weighted Average Exercise Price, Granted 0.00 0.42  
Weighted Average Exercise Price, Exercised 0.00 0.00  
Weighted Average Exercise Price, Expired 0.00 58.25  
Weighted Average Exercise Price, Forfeited 0.55 5.95  
Weighted Average Exercise Price, Ending Balance 3.65 $ 3.62 $ 15.18
Weighted Average Exercise Price, Exercisable $ 12.89    
Weighted Average Remaining Contractual Life, Balance Outstanding 5 years 11 months 23 days 6 years 6 months 4 days 6 years 2 months 9 days
Weighted Average Remaining Contractual Life, Exercisable 5 years 1 month 28 days    
Aggregate Intrinsic Value, Ending Balance $ 158,270 $ 153,353 $ 0
Aggregate Intrinsic Value, Exercisable 15,129    
Grant date fair value of options granted $ 0 $ 470,000  
Weighted average grant date fair value $ 0.00 $ 0.27