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
Sep. 30, 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]            
Class Of Stock [Line Items]            
Common stock, shares authorized 34,285,714          
Warrants issued price per share $ 0.35          
Proceeds from issuance of common stock $ 10.4          
Valuation of warrants $ 4.0          
Volatility rate 59.72%          
Risk-free interest rate 0.17%          
Expected dividend yield 0.00%          
Expected terms (In Years) 2 years 6 months          
Common stocvk reserve for issuance       34,285,714    
August 2020 Offering [Member] | Warrant [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]            
Class Of Stock [Line Items]            
Warrants issued during period 34,285,714          
August 2020 Offering [Member] | Placement Agent Warrants [Member]            
Class Of Stock [Line Items]            
Common stocvk reserve for issuance       2,399,999    
August 2020 Offering [Member] | Placement Agent Warrants [Member] | Warrant [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]            
Class Of Stock [Line Items]            
Placement agent warrants issued 2,399,999          
August 2020 Offering [Member] | Offering [Member]            
Class Of Stock [Line Items]            
Warrants issued price per share $ 0.4375