Annual report pursuant to Section 13 and 15(d)

Warrant Liability - Narrative (Details)

v3.10.0.1
Warrant Liability - Narrative (Details) - USD ($)
12 Months Ended
Jun. 22, 2018
Feb. 16, 2018
Feb. 09, 2017
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock issued for cash, IPO     3,710,000    
Shares issued, price per share (in dollars per share) $ 2.105        
Gross proceeds received from sale of shares and warrants   $ 9,000,000.0      
Exercisable period, subject to beneficial ownership limitations   6 months      
Warrants, exercise price (in dollars per share)   $ 2.80      
Warrant term   5 years      
Right of first refusal period (in months)   9 months      
Tail fee period (in months)   6 months      
Additional shares available for purchase       1,479,000  
Proceeds from issuance, IPO       $ 12,025,000 $ 6,071,000
Minimum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares issued, price per share (in dollars per share)     $ 1.35    
Maximum          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares issued, price per share (in dollars per share)     $ 1.50    
Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares)     1    
Series A Warrant          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrant term     5 years    
Class of warrants aggregate amounts (in shares)     278,250    
Series A Warrant | Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares)     0.50    
Series B Warrant          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants, exercise price (in dollars per share)     $ 1.35    
Warrant term     90 days    
Class of warrants aggregate amounts (in shares)     556,500    
Series B Warrant | Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares)     1    
Series C Warrant          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrant term     5 years    
Class of warrants aggregate amounts (in shares)     278,250    
Series C Warrant | Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares)     0.50    
Series A and Series C Warrants          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants, exercise price (in dollars per share)     $ 1.50    
Underwriting Agreement          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Warrants, exercise price (in dollars per share)     $ 0.001    
Additional shares available for purchase     556,500    
Price per share of common stock issued (in dollars per share)     $ 1.349    
Warrants exercised     $ 278,100    
Proceeds from issuance, IPO     $ 4,500,000    
June 2018 Registered Direct Offering          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Stock issued for cash, IPO 1,092,636        
Gross proceeds received from sale of shares and warrants $ 2,300,000        
Exercisable period, subject to beneficial ownership limitations 6 months        
Warrants, exercise price (in dollars per share) $ 2.02        
Warrant term 5 years        
June 2018 Registered Direct Offering | Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares) 710,212        
June 2018 Registered Direct Offering | Warrant          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares) 742,991        
Placement Agency Agreement          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Commission payment to agents (as a percent) 6.50% 6.50%      
Warrants granted to purchase common stock, percentage 3.00% 3.00%      
Reimbursement of expenses $ 50,000 $ 75,000      
Right of first refusal period (in months) 9 months        
Tail fee period (in months) 6 months        
Roth Warrants          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Common stock offered for each warrant (in shares) 32,779        
Warrants, exercise price (in dollars per share) $ 2.3155        
Class of warrants aggregate amounts (in shares)   128,700      
Securities Purchase Agreement          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Class of warrants aggregate amounts (in shares)   2,273,700      
Securities Purchase Agreement | Common Stock          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Shares of common stock sold   4,290,000      
Purchase price (in dollars per share)   $ 2.10      
Class of warrants aggregate amounts (in shares)   2,145,000