Quarterly report pursuant to Section 13 or 15(d)

Stockholders' deficit, Warrants (Details)

v3.20.2
Stockholders' deficit, Warrants (Details)
$ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended
Jun. 24, 2020
USD ($)
Director
$ / shares
shares
Mar. 17, 2020
$ / shares
shares
Dec. 19, 2019
$ / shares
shares
Nov. 04, 2019
USD ($)
$ / shares
shares
Sep. 17, 2019
$ / shares
shares
May 13, 2019
shares
May 10, 2019
shares
May 06, 2019
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2019
shares
Jun. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2019
USD ($)
Jun. 23, 2020
$ / shares
Dec. 31, 2019
USD ($)
Dec. 12, 2018
$ / shares
shares
Number of Warrants [Abstract]                              
Warrants outstanding (in shares)                     16,981,854        
Issued (in shares)                     3,064,456        
Terminated (in shares)                     (2,958,334)        
Warrants outstanding (in shares)                 17,087,976   17,087,976        
Weighted Average Exercise Price [Abstract]                              
Warrants outstanding (in dollars per share) | $ / shares                     $ 3.23        
Issued (in dollars per share) | $ / shares                     1.15        
Terminated (in dollars per share) | $ / shares                     (5.12)        
Warrants outstanding (in dollars per share) | $ / shares                 $ 2.37   $ 2.37        
Warrants acquired (in shares)               712,823              
Warrants acquired (in dollars per share) | $ / shares               $ 3.90              
Warrants, exercise price (in dollars per share) | $ / shares $ 5.0                       $ 4.25    
Proceeds from shares issued pursuant to private placement, net | $                     $ 0 $ 15,826      
Unit price (in dollars per share) | $ / shares                             $ 1.95
Warrants outstanding, intrinsic value | $                 $ 5,700   5,700     $ 12,200  
November 2019 Notes [Member] | Maximum [Member]                              
Weighted Average Exercise Price [Abstract]                              
Increase in fair value of warrants | $       $ 100                      
General and Administrative Expense [Member]                              
Weighted Average Exercise Price [Abstract]                              
Contract termination expense | $                 $ 5,700   $ 5,700        
General and Administrative Expense [Member] | November 2019 Notes [Member] | Minimum [Member]                              
Weighted Average Exercise Price [Abstract]                              
Increase in fair value of warrants | $ $ 200                            
Warrant [Member]                              
Weighted Average Exercise Price [Abstract]                              
Warrants, exercise price (in dollars per share) | $ / shares $ 1.25 $ 1.62             $ 3.90   $ 3.90        
Warrants, exercisable period 84 months               2 years   2 years        
Number of shares issuable per unit (in shares)   1,003,232             1,990,624   1,990,624       0.5
Number of non-employee directors | Director 2                            
Warrant [Member] | Maximum [Member]                              
Weighted Average Exercise Price [Abstract]                              
Number of warrants issuable if settled (in shares) 1,000,000                            
June 2020 Warrants [Member]                              
Weighted Average Exercise Price [Abstract]                              
Warrants, exercise price (in dollars per share) | $ / shares $ 1.25                            
Warrants, exercisable period 84 months                            
June 2020 Warrants [Member] | Maximum [Member]                              
Weighted Average Exercise Price [Abstract]                              
Number of warrants issuable if settled (in shares) 1,000,000                            
Series E Preferred Stock [Member]                              
Weighted Average Exercise Price [Abstract]                              
Number of shares acquired (in shares)               2,633,678              
Unit price (in dollars per share) | $ / shares               $ 6.00              
Stated value (in dollars per share) | $ / shares               0.99              
Conversion price (in dollars per share) | $ / shares               $ 0.78              
Conversion of Stock (in shares)           (236,364) (689,394)                
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) | $ / shares     $ 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) | $ / shares     $ 1.82                        
Warrants, exercisable period     24 months                        
Common Stock [Member]                              
Weighted Average Exercise Price [Abstract]                              
Conversion of Stock (in shares)           300,000 875,000                
Number of shares issuable per unit (in shares)                             1
Number of warrants issuable if settled (in shares)                 3,706,679   3,706,679        
Common Stock [Member] | Warrant [Member]                              
Weighted Average Exercise Price [Abstract]                              
Warrants, exercise price (in dollars per share) | $ / shares                 $ 0.75   $ 0.75        
Number of shares issuable per unit (in shares)                 1,990,624   1,990,624        
Common Stock [Member] | Series E Preferred Stock [Member]                              
Weighted Average Exercise Price [Abstract]                              
Conversion of Stock (in shares)                   1,175,000          
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) | $ / shares               $ 4.25              
Gross proceeds from issuance of warrants (in dollars per share) | $ / shares               $ 3.00              
Proceeds from shares issued pursuant to private placement, net | $               $ 15,700              
Holding period               6 months              
Broker [Member]                              
Weighted Average Exercise Price [Abstract]                              
Warrants, exercise price (in dollars per share) | $ / shares               $ 3.00              
Warrants, exercisable period               24 months              
Broker [Member] | PIPE Transaction [Member]                              
Number of Warrants [Abstract]                              
Issued (in shares)               220,539              
Advisor [Member] | Tranche One [Member]                              
Number of Warrants [Abstract]                              
Warrants outstanding (in shares)                 1,041,666   1,041,666        
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) | $ / shares         $ 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         12 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) | $ / shares         $ 10.00                    
Advisor [Member] | Exercise Price $10.00 [Member] | Tranche Three [Member]                              
Weighted Average Exercise Price [Abstract]                              
Warrants, exercisable period         18 months                    
Warrants exercisable (in shares)         1,500,000