Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Additional Information (Details)

v3.20.4
Stockholders' Equity - Additional Information (Details)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 08, 2020
USD ($)
$ / shares
shares
Apr. 09, 2019
USD ($)
Agreement
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Dec. 31, 2018
shares
Dec. 31, 2019
shares
Nov. 30, 2019
shares
Class Of Stock [Line Items]            
Warrants to purchase common stock     2,117,094   2,118,094  
Transaction costs | $     $ 207      
Remeasured fair value of warrants | $     19,711      
Change in fair value of warrant liability | $     $ 375      
Number of underwriting agreements | Agreement   2        
Aggregate gross proceeds from public offerings | $   $ 70,000        
Underwriting discounts and commissions and estimated offering expenses payable | $   $ 5,000        
Preferred stock, shares outstanding     0   0  
Series A Convertible Preferred Stock            
Class Of Stock [Line Items]            
Share price (in dollars per share) | $ / shares     $ 6.57      
Preferred stock, shares outstanding         0 666
Convertible preferred stock beneficial conversion feature | $     $ 600      
2019 Warrants            
Class Of Stock [Line Items]            
Warrants to purchase common stock         2,118,344  
Warrant exercise price of common stock per share | $ / shares     $ 8.625      
Warrants expiration date     Oct. 10, 2022      
Maximum ownership percentage to total number stock issued and outstanding holder is prohibited from conversion     4.99%      
Notice period for change in owning percentage     61 days      
Warrants outstanding and remain unexercised     2,117,094      
Fair value of warrants | $     $ 9,000      
Weighted Average | 2019 Warrants | Expected volatility            
Class Of Stock [Line Items]            
Fair value of weighted average volatility   86.06%        
Weighted Average | 2019 Warrants | Dividend yield            
Class Of Stock [Line Items]            
Fair value of weighted expected term   3 years 6 months        
Private Placement            
Class Of Stock [Line Items]            
Warrants to purchase common stock     2,828,125      
Gross proceeds of private placement | $ $ 90,500          
Transaction costs | $ 400          
Initial fair value of warrants at issuance | $ $ 19,300          
Remeasured fair value of warrants | $     $ 19,700      
Change in fair value of warrant liability | $     $ 400      
Public Offering | Common Stock Agreement | 2019 Warrants            
Class Of Stock [Line Items]            
Warrants to purchase common stock   1,951,844        
Share price (in dollars per share) | $ / shares   $ 7.50 $ 7.50      
Public Offering | Preferred Stock Agreement | Series A Convertible Preferred Stock            
Class Of Stock [Line Items]            
Shares issued   666        
Public Offering | Preferred Stock Agreement | 2019 Warrants            
Class Of Stock [Line Items]            
Warrants to purchase common stock   166,500        
Share price (in dollars per share) | $ / shares   $ 7,500        
Common Stock | Series A Convertible Preferred Stock            
Class Of Stock [Line Items]            
Conversion of series A stock into common stock           666,000
Common Stock | Private Placement            
Class Of Stock [Line Items]            
Shares issued 10,312,500     144,505    
Common Stock | Public Offering | Common Stock Agreement            
Class Of Stock [Line Items]            
Shares issued   8,667,333        
Pre-Funded Warrant | Private Placement            
Class Of Stock [Line Items]            
Warrants to purchase common stock 1,000,000          
Share price (in dollars per share) | $ / shares $ 8.00          
Warrants | Private Placement            
Class Of Stock [Line Items]            
Share price (in dollars per share) | $ / shares $ 7.99          
Warrants | Private Placement | Maximum            
Class Of Stock [Line Items]            
Warrants to purchase common stock 2,828,125