Quarterly report pursuant to Section 13 or 15(d)

Convertible Preferred Stock and Warrants (Details)

v3.20.1
Convertible Preferred Stock and Warrants (Details)
$ / shares in Units, $ in Millions
 3 Months Ended
Apr. 09, 2019
USD ($)
Agreement
$ / shares
shares
Mar. 31, 2020
USD ($)
$ / shares
shares
Dec. 31, 2019
shares
Nov. 30, 2019
shares
Class Of Stock [Line Items]        
Number of underwriting agreements | Agreement 2      
Warrants to purchase common stock 2,118,094      
Aggregate gross proceeds from public offerings | $ $ 70.0      
Underwriting discounts and commissions and estimated offering expenses payable | $ $ 5.0      
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 | $   $ 0.6    
Class A 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 exercisable 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   2,118,094    
Change fair value of warrants | $   $ 9.0    
Class A Warrants | Weighted Average Volatility | Weighted Average        
Class Of Stock [Line Items]        
Fair value of weighted average volatility   86.06%    
Class A Warrants | Weighted Average Expected Term | Weighted Average        
Class Of Stock [Line Items]        
Fair value of weighted expected term   3 years 6 months    
Common Stock | Series A Convertible Preferred Stock        
Class Of Stock [Line Items]        
Conversion of series A stock into common stock       666,000
Public Offering | Common Stock Agreement | Class A 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 | Common Stock Agreement | Common Stock        
Class Of Stock [Line Items]        
Shares issued 8,667,333      
Public Offering | Preferred Stock Agreement | Series A Convertible Preferred Stock        
Class Of Stock [Line Items]        
Shares issued 666      
Public Offering | Preferred Stock Agreement | Class A Warrants        
Class Of Stock [Line Items]        
Warrants to purchase common stock 166,500      
Share price (in dollars per share) | $ / shares $ 7,500