Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt (Details Textual)

v3.20.1
Long-Term Debt (Details Textual) - USD ($)
3 Months Ended
Dec. 09, 2019
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
May 30, 2019
Debt Instrument [Line Items]          
Additional warrant issuances   10.00%      
Warrants expiration period   5 years     7 years
Warrant exercise price percentage   110.00%      
Warrant liability   $ 7,200,000   $ 16,300,000  
Convertible Note, at fair value          
Debt Instrument [Line Items]          
Face amount $ 41,000,000.0        
Interest rate 4.50%        
Conversion price $ 3.05        
Principal amount outstanding, convertible debt   36,000,000.0   $ 40,500,000  
Fair value option, gain (loss) related to change in fair value   (11,400,000)      
Financial liability, fair value option, unrealized gain (losses) during period   1,100,000      
Convertible debt   $ 4,500,000      
Shares issued upon conversion   1,546,889      
Redemption price, percentage   112.00%      
Periodic payment, principal   $ 1,500,000      
Liquidity requirements, cash and cash equivalents $ 8,000,000.0        
Warrants to purchase of common stock shares (in shares) 15,459,016        
Weighted average period, common stock, price   30 days      
Exercise price of warrants (in usd per share) $ 3.05        
Convertible Note, at fair value | Interest Expense          
Debt Instrument [Line Items]          
Fair value option, gain (loss) related to change in fair value   $ (5,100,000)      
Loss on conversion   900,000      
Convertible Note, at fair value | Credit Risk          
Debt Instrument [Line Items]          
Fair value option, gain (loss) related to change in fair value   1,100,000      
Financial liability, fair value option, unrealized gain (losses) during period   $ 1,100,000 $ 0    
Credit Agreement          
Debt Instrument [Line Items]          
Exercise price of warrants (in usd per share)   $ 1.25      
Warrants to purchase common stock (in shares)       8,053,390