Quarterly report pursuant to Section 13 or 15(d)

Equity Offerings - Additional Information (Details)

v3.20.2
Equity Offerings - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended
Aug. 31, 2020
Jun. 30, 2020
May 31, 2020
May 22, 2020
Dec. 31, 2019
Class Of Stock [Line Items]          
Common stock, shares authorized   300,000,000     300,000,000
Common stock, par value   $ 0.0001     $ 0.0001
Stock issued during period shares warrants Exercised   1,837,667      
May 2020 Offering [Member]          
Class Of Stock [Line Items]          
Common stock, shares authorized     22,222,222    
Warrants issued price per share       $ 0.45  
Proceeds from issuance of common stock     $ 8.7    
Other offering expenses     1.3    
Valuation of warrants     $ 3.5    
Volatility rate     59.86%    
Risk-free interest rate     0.34%    
Expected dividend yield     0.00%    
Expected terms (In Years)     2 years 6 months    
Common stocvk reserve for issuance   20,384,555      
May 2020 Offering [Member] | Warrant [Member]          
Class Of Stock [Line Items]          
Common stock, par value     $ 0.45    
Equity offering description     Each share of common stock was sold in the offering with one warrant to purchase one share of common stock.    
Warrants issued price per share     $ 0.45    
Warrants expire period     5 years    
May 2020 Offering [Member] | Maximum [Member] | Warrant [Member]          
Class Of Stock [Line Items]          
Warrants issued during period     22,222,222    
May 2020 Offering [Member] | Placement Agent Warrants [Member]          
Class Of Stock [Line Items]          
Common stocvk reserve for issuance   1,555,555      
May 2020 Offering [Member] | Placement Agent Warrants [Member] | Warrant [Member]          
Class Of Stock [Line Items]          
Warrants issued price per share     $ 0.5625    
common stock expire period     5 years    
May 2020 Offering [Member] | Placement Agent Warrants [Member] | Maximum [Member] | Warrant [Member]          
Class Of Stock [Line Items]          
Placement agent warrants issued     1,555,555    
May 2020 Offering [Member] | Offering [Member]          
Class Of Stock [Line Items]          
Warrants issued price per share       $ 0.5625  
August 2020 Offering [Member] | Subsequent Event [Member]          
Class Of Stock [Line Items]          
Common stock, shares authorized 34,285,714        
Proceeds from issuance of common stock $ 10.6        
August 2020 Offering [Member] | Warrant [Member] | Subsequent Event [Member]          
Class Of Stock [Line Items]          
Common stock, par value $ 0.35        
Equity offering description Each share of common stock was sold in the offering with one warrant to purchase one share of common stock.        
Warrants issued price per share $ 0.35        
Warrants expire period 5 years        
August 2020 Offering [Member] | Maximum [Member] | Warrant [Member] | Subsequent Event [Member]          
Class Of Stock [Line Items]          
Warrants issued during period 34,285,714        
August 2020 Offering [Member] | Placement Agent Warrants [Member] | Warrant [Member] | Subsequent Event [Member]          
Class Of Stock [Line Items]          
Warrants issued price per share $ 0.4375        
common stock expire period 5 years        
August 2020 Offering [Member] | Placement Agent Warrants [Member] | Maximum [Member] | Warrant [Member] | Subsequent Event [Member]          
Class Of Stock [Line Items]          
Placement agent warrants issued 2,399,999