Annual report pursuant to Section 13 and 15(d)

Stock-based compensation - Narrative (Details)

v3.3.1.900
Stock-based compensation - Narrative (Details) - USD ($)
1 Months Ended 12 Months Ended
Feb. 27, 2016
Nov. 30, 2014
Aug. 31, 2014
Jun. 30, 2014
Feb. 28, 2014
Oct. 31, 2013
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation             $ 811,658 $ 538,954
Unrecognized compensation cost related to unvested stock-based awards             1,900,000 4,600,000
Fair value of options vested             918,424 266,769
General and Administrative Expense [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation             $ 811,658 $ 538,954
Mr. Segal [Member] | Subsequent Event [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of options forfeited 228,088              
Mr. Goldfinger [Member] | Subsequent Event [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of options forfeited 114,044              
Employee Stock Option [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Granted (in shares)   115,000 275,000 690,000 200,000   0  
Granted (in dollars per share)   $ 4.90 $ 5.00 $ 4.85 $ 6.00   $ 0.00  
Number of options forfeited             351,500  
Unrecognized compensation cost, recognition period             4 years 5 months 19 days  
Options granted, weighted-average grant date fair value (in dollars per share)             $ 1.86 $ 1.88
Employee Stock Option [Member] | Mr. Segal [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Granted (in shares)           1,022,104    
Granted (in dollars per share)           $ 5.00    
Employee Stock Option [Member] | Mr. Segal [Member] | Time Period [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting rate (percent)           50.00%    
Employee Stock Option [Member] | Mr. Segal [Member] | Achievement of Targeted Annual Milestones [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting rate (percent)           50.00%    
Employee Stock Option [Member] | Mr. Goldfinger [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Granted (in shares)           511,052    
Granted (in dollars per share)           $ 5.00    
Employee Stock Option [Member] | Mr. Goldfinger [Member] | Time Period [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting rate (percent)           50.00%    
Employee Stock Option [Member] | Mr. Goldfinger [Member] | Achievement of Targeted Annual Milestones [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting rate (percent)           50.00%    
Unrestricted Stock [Member] | Directors [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation             $ 160,000  
2013 Employee, Director and Consultant Equity Incentive Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Authorized shares           4,773,992    
Contractual term           10 years    
Option vesting period           5 years