Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Equity Offerings (Details)

v3.20.2
Stockholders' Equity - Equity Offerings (Details)
3 Months Ended 6 Months Ended
Jan. 29, 2019
USD ($)
Institution
$ / shares
shares
Jan. 28, 2019
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
shares
Mar. 31, 2020
USD ($)
Mar. 31, 2019
USD ($)
Jun. 30, 2020
USD ($)
shares
Dec. 31, 2019
shares
Apr. 17, 2019
USD ($)
Stockholders' Equity                
Common stock authorized (in shares) | shares     200,000,000     200,000,000 200,000,000  
Preferred stock authorized (in shares) | shares     5,000,000     5,000,000 5,000,000  
Issuance of common stock (in shares) | shares           28,100,000    
Issuance of common stock, net of issuance costs     $ 32,029,000 $ 3,551,000 $ 8,896,000      
Wainwright                
Stockholders' Equity                
Percentage of aggregate gross proceeds paid   7.00%            
Expenses paid   $ 50,000            
Warrants to purchase shares of common stock | shares   500,000            
Warrants term   5 years            
Exercise price (in dollars per share) | $ / shares   $ 1.25            
At-the-market sales facility - April 17, 2019 agreement                
Stockholders' Equity                
Offering amount               $ 50,000,000.0
Issuance of common stock, net of issuance costs           $ 32,000,000.0    
Remaining available for future issuances     $ 12,100,000     $ 12,100,000    
Private Placement                
Stockholders' Equity                
Issuance of common stock (in shares) | shares 10,000,000              
Offering price (in dollars per share) | $ / shares $ 1.00              
Issuance of common stock, net of issuance costs $ 9,200,000              
Number of institutional investors | Institution 2