Quarterly report pursuant to Section 13 or 15(d)

Warrant Liability - Narrative (Details)

v3.19.3
Warrant Liability - Narrative (Details) - $ / shares
1 Months Ended 9 Months Ended
Apr. 25, 2019
Mar. 29, 2019
Apr. 30, 2019
Mar. 31, 2019
Jun. 30, 2018
Feb. 28, 2018
Feb. 28, 2017
Sep. 30, 2019
Dec. 31, 2018
Warrant                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Warrants balance (shares)               10,256,193 3,426,711
Number of shares under warrants granted (shares)     5,250,000 1,585,500 742,991 2,273,700 404,002 8,242,500  
April Offerings                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Exercised price per warrant (usd per share)     $ 1.75            
April Offerings | Warrant                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Exercised price per warrant (usd per share) $ 1.75                
Expected life (years) 5 years                
April Offerings | Common Stock                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Shares authorized (shares) 4,687,500                
April Offerings | Common Stock | Underwiters                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Shares authorized (shares) 562,500                
March 2019 Registered Direct Offerings                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Exercised price per warrant (usd per share)       $ 1.10          
March 2019 Registered Direct Offerings | Common Stock                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Shares authorized (shares)   2,625,000              
Exercised price per warrant (usd per share)   $ 1.10              
Expected life (years)   5 years              
March 2019 Registered Direct Offerings | Common Stock | Underwiters                  
Share-based Compensation Arrangement by Share-based Payment Award                  
Shares authorized (shares)   367,500              
Exercised price per warrant (usd per share)   $ 1.10