Quarterly report pursuant to Section 13 or 15(d)

Stockholders' deficit, Equity Transactions (Details)

v3.20.1
Stockholders' deficit, Equity Transactions (Details)
$ / shares in Units, $ in Millions
Jan. 02, 2020
USD ($)
shares
Feb. 12, 2019
USD ($)
$ / shares
shares
Dec. 12, 2018
USD ($)
$ / shares
shares
Mar. 31, 2020
shares
Mar. 30, 2020
shares
Mar. 05, 2020
shares
Mar. 03, 2020
Director
shares
Jan. 13, 2020
shares
Dec. 31, 2019
shares
Common Stock [Abstract]                  
Common stock, shares issued (in shares)       48,939,708       72,720 47,977,390
Units issued in private placement offering (in shares)     1,425,641            
Unit price (in dollars per share) | $ / shares     $ 1.95            
Gross proceeds from private placement offering | $     $ 2.8            
Share issuance costs | $     $ 0.1            
Reserved Shares of Common Stock for Future Issuance [Abstract]                  
Conversion of Series E (in shares)       1,760,903         1,760,903
Exercise of options to purchase common stock (in shares)       7,891,833         7,791,833
Warrants to purchase common stock (in shares)       18,046,310         16,981,854
Notes payable (in shares)       4,722,795         4,437,500
Total (in shares)       32,421,841         30,972,090
Series A Preferred Units [Member]                  
Common Stock [Abstract]                  
Units issued in private placement offering (in shares)   69,115              
Unit price (in dollars per share) | $ / shares   $ 2.17              
Gross proceeds from private placement offering | $   $ 0.2              
Common Stock [Member] | Advertising Services [Member]                  
Common Stock [Abstract]                  
Common stock, shares issued (in shares)           125,000      
Common Stock [Member] | Investor [Member]                  
Common Stock [Abstract]                  
Common stock, shares issued (in shares) 308,642                
Gross proceeds from private placement offering | $ $ 0.5                
Common Stock [Member] | Investor [Member] | Maximum [Member]                  
Common Stock [Abstract]                  
Share issuance costs | $ $ 0.1                
Common Stock [Member] | ABG [Member]                  
Common Stock [Abstract]                  
Common stock, shares issued (in shares)               72,720  
Restricted Stock [Member]                  
Common Stock [Abstract]                  
Common stock, shares issued (in shares)             450,000    
Number of non-employee directors | Director             3    
Restricted Stock [Member] | Officer [Member]                  
Common Stock [Abstract]                  
Common stock, shares issued (in shares)         5,956