Quarterly report pursuant to Section 13 or 15(d)

Stockholders' deficit, Warrants (Details)

v3.20.1
Stockholders' deficit, Warrants (Details) - USD ($)
$ / shares in Units, $ in Millions
 3 Months Ended
Mar. 17, 2020
Dec. 19, 2019
Nov. 04, 2019
Sep. 17, 2019
May 06, 2019
Mar. 31, 2020
Dec. 31, 2019
Number of Warrants [Abstract]              
Warrants outstanding (in shares)           16,981,854  
Issued (in shares)           1,064,456  
Exercised (in shares)           0  
Warrants outstanding (in shares)           18,046,310  
Weighted Average Exercise Price [Abstract]              
Warrants outstanding (in dollars per share)           $ 3.23  
Issued (in dollars per share)           1.81  
Exercised (in dollars per share)           0  
Warrants outstanding (in dollars per share)           $ 3.05  
Warrants acquired (in shares)         712,823    
Warrants acquired (in dollars per share)         $ 3.9    
Warrants outstanding, intrinsic value           $ 2.6 $ 12.2
Exercise Price $5.00 [Member]              
Number of Warrants [Abstract]              
Issued (in shares)   937,500 11,000        
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)   $ 5.00 $ 5.00        
Warrants, exercisable period   24 months 24 months        
Exercise price $1.82 [Member]              
Number of Warrants [Abstract]              
Issued (in shares)   6,500,000          
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)   $ 1.82          
Warrants, exercisable period   24 months          
PIPE Transaction [Member]              
Number of Warrants [Abstract]              
Issued (in shares) 1,003,232       5,744,991    
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)         $ 4.25    
Broker [Member]              
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)         $ 3.00    
Warrants, exercisable period         24 months    
Broker [Member] | PIPE Transaction [Member]              
Number of Warrants [Abstract]              
Issued (in shares)         220,539    
Advisor [Member] | Exercise Price $0.10 [Member]              
Number of Warrants [Abstract]              
Issued (in shares)       2,500,000      
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)       $ 0.10      
Advisor [Member] | Exercise Price $0.10 [Member] | Tranche One [Member]              
Weighted Average Exercise Price [Abstract]              
Warrants, exercisable period       12 months      
Warrants exercisable (in shares)       1,250,000      
Advisor [Member] | Exercise Price $0.10 [Member] | Tranche Two [Member]              
Weighted Average Exercise Price [Abstract]              
Warrants, exercisable period       18 months      
Warrants exercisable (in shares)       1,250,000      
Advisor [Member] | Exercise Price $10.00 [Member]              
Number of Warrants [Abstract]              
Issued (in shares)       1,500,000      
Weighted Average Exercise Price [Abstract]              
Warrants, exercise price (in dollars per share)       $ 10.00      
Warrants, exercisable period       18 months      
Warrants exercisable (in shares)       1,500,000