Quarterly report pursuant to Section 13 or 15(d)

Convertible Note and Long-Term Debt (Details Textual)

v3.20.2
Convertible Note and Long-Term Debt (Details Textual) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Apr. 14, 2020
Dec. 09, 2019
Aug. 10, 2020
Aug. 03, 2020
Jun. 30, 2020
Jun. 30, 2020
Dec. 31, 2019
Jun. 05, 2019
Dec. 31, 2018
Debt Instrument [Line Items]                  
Conversion of convertible note, amount           $ 38,735,019      
Additional warrant issuances           10.00%      
Warrants expiration period         5 years 5 years   7 years  
Warrant exercise price percentage           110.00%      
Change in fair value for the period           $ 12,200,000      
Warrant liability         $ 0 $ 0 $ 16,300,000    
Warrant                  
Debt Instrument [Line Items]                  
Issuance of common stock (in shares)           8,053,390      
Convertible Note, at fair value                  
Debt Instrument [Line Items]                  
Convertible Note, at fair value         95,330,000 $ 95,330,000 39,020,000    
Principal amount outstanding, convertible debt         18,500,000 18,500,000 $ 40,500,000    
Fair value option, gain (loss) related to change in fair value           56,300,000      
Financial liability, fair value option, unrealized gain (losses) during period           1,100,000      
Conversion of convertible note, amount         $ 17,500,000 $ 22,000,000.0      
Shares issued upon conversion (in shares)         6,837,381 8,384,270      
Class of Warrant or Right, Number of Warrants Exercisable Following Redemption of Convertible Note         6,975,410 6,975,410      
Weighted average period, common stock, price         30 days        
Face amount   $ 41,000,000.0              
Interest rate   4.50%              
Conversion price   $ 3.05              
Redemption price, percentage         112.00% 115.00%      
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              
Exercise price of warrants (in usd per share)   $ 3.05              
Convertible Note, at fair value | Subsequent Event                  
Debt Instrument [Line Items]                  
Convertible Note, at fair value     $ 0            
Conversion of convertible note, amount       $ 18,500,000          
Shares issued upon conversion (in shares)       6,065,576          
Convertible Note, at fair value | Interest Expense                  
Debt Instrument [Line Items]                  
Fair value option, gain (loss) related to change in fair value           $ (75,200,000)      
Loss on conversion         $ 20,100,000 $ 21,000,000.0      
Convertible Note, at fair value | Interest Expense | Subsequent Event                  
Debt Instrument [Line Items]                  
Loss on conversion       $ (14,900,000)          
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
Credit Agreement | Subsequent Event                  
Debt Instrument [Line Items]                  
Exercise price of warrants (in usd per share)     $ 20.90            
Warrants to purchase common stock (in shares)     409,356            
Warrants expiration period     5 years            
Warrant exercise price percentage     110.00%            
Paycheck Protection Program Term Note                  
Debt Instrument [Line Items]                  
CARES Act, proceeds from loans payable $ 1,400,000                
CARES Act, interest rate 1.00%