Annual report pursuant to Section 13 and 15(d)

Capital Structure - Common Stock (Details)

v3.8.0.1
Capital Structure - Common Stock (Details)
3 Months Ended 12 Months Ended
Nov. 17, 2017
USD ($)
shares
Apr. 27, 2017
USD ($)
$ / shares
shares
Sep. 08, 2016
USD ($)
$ / shares
shares
Nov. 23, 2015
USD ($)
shares
Oct. 20, 2015
USD ($)
class_of_stock
$ / shares
shares
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
class_of_stock
Vote
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Dec. 31, 2015
USD ($)
shares
Jan. 27, 2017
USD ($)
Aug. 31, 2014
$ / shares
shares
Common Stock                      
Number of classes of stock authorized to issue | class_of_stock         2            
Number of shares of capital stock authorized to issue (in shares)             205,000,000        
Common stock, shares authorized (in shares)             200,000,000 200,000,000      
Preferred stock, shares authorized (in shares)             5,000,000 0      
Common stock, par value (in dollars per share) | $ / shares             $ 0.001 $ 0.001      
Preferred stock, par value per share (in dollars per share) | $ / shares             $ 0.001 $ 0.001      
Initial Public Offering [Abstract]                      
Gross proceeds | $       $ 135,319     $ 1,502,593 $ 1,899,987 $ 21,165,589    
Underwriter's Unit Purchase Option [Abstract]                      
Threshold price per common stock on any trading day to present notice for purchase of common stock | $ / shares     $ 0.50                
Number of shares sold under purchase agreement (in shares)             31,266,989 9,434,141      
Proceeds from issuance of common stock | $             $ 1,693,498 $ 2,003,182      
Common stock                      
Common Stock                      
Number of shares available under warrant (in shares)                     22,328
Initial Public Offering [Abstract]                      
Exercise price per share (in dollars per share) | $ / shares                     $ 8.40
Issuance of stock (in shares)             2,301,598 763,998 4,020,000    
Gross proceeds | $             $ 2,302 $ 764 $ 4,020    
Aspire Capital Fund LLC (Aspire Capital)                      
Underwriter's Unit Purchase Option [Abstract]                      
Term of common stock purchase agreement     30 months                
Common stock issued as commitment fee     175,000                
Capital Unit                      
Initial Public Offering [Abstract]                      
Exercise price per share (in dollars per share) | $ / shares         $ 5.23            
Issuance of stock (in shares)         4,000,000            
Share price (in dollars per share) | $ / shares         $ 6.50            
Gross proceeds | $         $ 26,000,000            
Net proceeds from IPO | $         23,600,000            
Underwriter's Unit Purchase Option [Abstract]                      
Proceeds from unit purchase option | $         $ 100            
Units available, as a percentage of units sold         1.00%            
Equity purchase option unit, exercise price per unit | $ / shares         $ 7.48            
Equity purchase option unit, exercise price as percent of IPO price         115.00%            
Capital Unit, Class B                      
Initial Public Offering [Abstract]                      
Exercise price per share (in dollars per share) | $ / shares         $ 4.49            
Class A Warrant                      
Initial Public Offering [Abstract]                      
Number of equity instruments included in a unit         1            
Exercise price per share (in dollars per share) | $ / shares         $ 4.55            
Issuance of stock (in shares)       551,900              
Underwriter's Unit Purchase Option [Abstract]                      
Equity purchase option, unit exercise price after first warrant expiration | $ / shares         7.475            
Equity purchase option, unit exercise price after second warrant expiration | $ / shares         $ 7.47            
Class B Warrant                      
Initial Public Offering [Abstract]                      
Number of equity instruments included in a unit         1            
Exercise price per share (in dollars per share) | $ / shares         $ 3.90            
Issuance of stock (in shares)       551,900              
Common Stock                      
Common Stock                      
Number of shares available under warrant (in shares)             18,986,859        
Initial Public Offering [Abstract]                      
Number of equity instruments included in a unit         1            
Issuance of stock (in shares)       20,000              
Underwriter's Unit Purchase Option [Abstract]                      
Number of votes per share | Vote             1        
Number of preemptive, conversion or subscription rights | class_of_stock             0        
Number of redemption or sinking fund provisions | class_of_stock             0        
Common Stock | Class A Warrant                      
Initial Public Offering [Abstract]                      
Class of warrant or right, number of securities called by each warrant or right       1 1            
Series B convertible preferred stock | Preferred Stock                      
Common Stock                      
Number of shares available under warrant (in shares)                     625,208
Initial Public Offering [Abstract]                      
Exercise price per share (in dollars per share) | $ / shares                     $ 0.2999
Maximum | Capital Unit                      
Underwriter's Unit Purchase Option [Abstract]                      
Number of units available under the option         40,000            
Private Placement                      
Common Stock                      
Proceeds from issuance or sale of equity | $   $ 4,650,000                  
Number of shares available under warrant (in shares)   14,285,714                  
Convertible preferred stock conversion price (in dollars per share) | $ / shares   $ 0.35                  
Initial Public Offering [Abstract]                      
Exercise price per share (in dollars per share) | $ / shares   $ 0.40                  
Gross proceeds | $   $ 5,000,000                  
Private Placement | Common stock                      
Common Stock                      
Percentage of outstanding shares issued   19.99%                  
Convertible preferred stock shares authorized (in shares)   11,940,000                  
Initial Public Offering [Abstract]                      
Issuance of stock (in shares)   2,345,714                  
Private Placement | Series A Preferred Stock | Preferred Stock                      
Common Stock                      
Preferred stock, shares authorized (in shares)   4,179                  
Preferred stock, par value per share (in dollars per share) | $ / shares   $ 1,000                  
IPO | Class B Warrant                      
Initial Public Offering [Abstract]                      
Class of warrant or right, number of securities called by each warrant or right         0.5            
Common Stock Purchase Agreement | Aspire Capital Fund LLC (Aspire Capital)                      
Initial Public Offering [Abstract]                      
Gross proceeds | $     $ 1,000,000     $ 789,000          
Underwriter's Unit Purchase Option [Abstract]                      
Maximum value of common stock purchases committed to by counterparty | $     $ 15,000,000                
Number of shares sold under purchase agreement (in shares)     250,000       965,165        
Price per share (in dollars per share) | $ / shares     $ 4.00                
Proceeds from issuance of common stock | $               $ 1,900,000      
Common Stock Purchase Agreement | Maximum | Aspire Capital Fund LLC (Aspire Capital)                      
Underwriter's Unit Purchase Option [Abstract]                      
Number of common stock issued per day on achieving threshold price per common stock     50,000                
Equity Distribution Agreement for Sale of Common Stock | Maxim Group LLC (Maxim)                      
Underwriter's Unit Purchase Option [Abstract]                      
Proceeds from issuance of common stock | $             $ 905,000        
Payments of stock issuance costs | $             $ 33,000        
Sale of common stock through equity distribution agreement | $                   $ 12,075,338  
Equity Distribution Agreement for Sale of Common Stock | Maxim Group LLC (Maxim) | Common stock                      
Initial Public Offering [Abstract]                      
Issuance of stock (in shares)             1,336,433        
Equity Distribution Agreement for Sale of Common Stock | Common Stock | Maxim Group LLC (Maxim)                      
Underwriter's Unit Purchase Option [Abstract]                      
Shares available to be issued | $             $ 2,900,000        
Over-Allotment Option | Common Stock | Class B Warrant                      
Initial Public Offering [Abstract]                      
Class of warrant or right, number of securities called by each warrant or right       0.5              
TRx                      
Common Stock                      
Contingent shares issuable as part of acquisition (in shares) 2,349,968                    
Unregistered shares of common stock issued or issuable as part of acquisition | $ $ 8,100,000                    
Shares issued upon closing (in shares) 5,184,920