Quarterly report pursuant to Section 13 or 15(d)

Stock-based compensation - Narrative (Details)

v3.7.0.1
Stock-based compensation - Narrative (Details) - USD ($)
1 Months Ended 3 Months Ended
Oct. 31, 2013
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options outstanding (in shares)   1,649,512   1,857,012
Stock-based compensation   $ 153,339 $ 143,967  
Restricted Stock        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options outstanding (in shares)   708,750   716,250
Stock Options        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Unrecognized compensation cost related to unvested stock-based awards   $ 1,800,000    
Unrecognized compensation cost, recognition period   2 years 5 months 1 day    
Options granted, weighted-average grant date fair value (in dollars per share)   $ 1.65    
Stock Options | General and Administrative Expense        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Stock-based compensation   $ 153,339 $ 143,967  
The 2013 Plan        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Authorized shares (in shares) 4,773,992      
Contractual term 10 years      
Award vesting period 5 years