Quarterly report pursuant to Section 13 or 15(d)

Capitalization and Equity Structure - Warrants (Details)

v3.20.2
Capitalization and Equity Structure - Warrants (Details) - $ / shares
shares in Thousands
 1 Months Ended 6 Months Ended
Jun. 30, 2020
Dec. 31, 2015
Jun. 30, 2020
Dec. 31, 2019
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     1,178  
Warrants issued (in shares)     996  
Exercised (in shares)     (223)  
Expired (in shares)     (6)  
Ending balance (in shares) 1,945   1,945  
June 2020 Investor Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 5.18   $ 5.18  
Term (Years) 5 years 6 months   5 years 6 months  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     0  
Warrants issued (in shares)     874  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 874   874  
June 2020 Placement Agent Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 5.64   $ 5.64  
Term (Years)     5 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     0  
Warrants issued (in shares)     122  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 122   122  
December 2019 Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 8.10   $ 8.10  
Term (Years)     5 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     556  
Warrants issued (in shares)     0  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 556   556  
December 2019 Placement Agent Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 8.44   $ 8.44  
Term (Years)     5 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     52  
Warrants issued (in shares)     0  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 52   52  
May 2019 Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 3.52   $ 3.52  
Term (Years)     5 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     444  
Warrants issued (in shares)     0  
Exercised (in shares)     (223)  
Expired (in shares)     0  
Ending balance (in shares) 221   221  
2017 Information Agent Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 22.50   $ 22.50  
Term (Years)     3 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     13  
Warrants issued (in shares)     0  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 13   13  
2015 Warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 41.25   $ 41.25 $ 56.10
Term (Years)     5 years  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     107  
Warrants issued (in shares)   141 0  
Exercised (in shares)     0  
Expired (in shares)     0  
Ending balance (in shares) 107   107  
Pre-2014 warrants        
Schedule of Capitalization, Equity [Line Items]        
Exercise price (in dollars per share) $ 144.90   $ 144.90  
Class Of Warrant Or Right, Outstanding [Roll Forward]        
Beginning balance (in shares)     6  
Warrants issued (in shares)     0  
Exercised (in shares)     0  
Expired (in shares)     (6)  
Ending balance (in shares) 0   0  
Pre-2014 warrants | Minimum        
Schedule of Capitalization, Equity [Line Items]        
Term (Years)     9 years  
Pre-2014 warrants | Maximum        
Schedule of Capitalization, Equity [Line Items]        
Term (Years)     10 years