Quarterly report pursuant to Section 13 or 15(d)

Stock options and warrants (Stock incentive plan options) (Narrative) (Details)

v3.5.0.2
Stock options and warrants (Stock incentive plan options) (Narrative) (Details) - USD ($)
9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Sep. 01, 2015
Aug. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of shares reserved under the Plan       709,141 459,141
Stock-based compensation $ 368,459 $ 1,019,067      
Stock Incentive Plan [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Options exercised      
Incentive stock options exercised to purchase common shares      
Options granted 227,000        
Options granted, exercise price $ 2.89        
Options forfeited 25,445 27,178      
Options expired 21,825 4,644      
Options forfeited, unvested 3,620 22,534      
Options forfeited, exercise price $ 36.30        
Options expired, exercise price 39.81 $ 90.88      
Options forfeited, unvested, exercise price $ 15.13 $ 16.40      
Fair value of options vested $ 362,979 $ 461,000      
Expected to vest 143,000        
Unrecognized compensation cost $ 201,000        
Unrecognized compensation cost, period for recognition 1 year        
Awards outstanding 534,115   332,560    
Stock Incentive Plan [Member] | Independent Directors [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period   1 year      
Options granted 77,000 43,000      
Options granted, exercise price $ 2.89 $ 15.12      
Expiration period 10 years 10 years      
Percent of shares vesting on the six month anniversary from grant date 25.00% 25.00%      
Stock Incentive Plan [Member] | Independent Directors [Member] | Vesting in Period One [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 50.00% 25.00%      
Stock Incentive Plan [Member] | Independent Directors [Member] | Vesting In Period Two [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 25.00% 25.00%      
Stock Incentive Plan [Member] | Independent Directors [Member] | Vesting In Period Three [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 25.00% 25.00%      
Stock Incentive Plan [Member] | Independent Directors [Member] | Vesting In Period Four [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate   25.00%      
Stock Incentive Plan [Member] | Officers and Employees [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period   2 years      
Options granted 150,000 93,813      
Options granted, exercise price $ 2.89 $ 15.12      
Expiration period 10 years 10 years      
Stock Incentive Plan [Member] | Officers and Employees [Member] | Vesting in Period One [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 50.00% 50.00%      
Stock Incentive Plan [Member] | Officers and Employees [Member] | Vesting In Period Two [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 50.00% 50.00%      
Stock Incentive Plan [Member] | Minimum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Expiration period 3 years        
Stock Incentive Plan [Member] | Maximum [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Expiration period 5 years        
Nonqualified [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Options exercised        
Incentive stock options exercised to purchase common shares        
Options granted 95,000      
Options granted, exercise price $ 3.78        
Options forfeited        
Options forfeited, exercise price        
Awards outstanding 527,003   432,003    
Stock-based compensation $ 2,961      
Nonqualified [Member] | New Employees [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting period 2 years        
Options granted 95,000        
Options granted, exercise price $ 3.78        
Expiration period 10 years        
Unrecognized compensation cost $ 234,000        
Unrecognized compensation cost, period for recognition 2 years        
Nonqualified [Member] | New Employees [Member] | Vesting in Period One [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 50.00%        
Nonqualified [Member] | New Employees [Member] | Vesting In Period Two [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Vesting rate 50.00%        
Nonqualified [Member] | Non-compensatory Rights [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Options granted, exercise price $ 15.40        
Awards outstanding 429,503        
Expiration Date May 31, 2018        
Nonqualified [Member] | Compensatory Rights [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Options granted, exercise price $ 4.38        
Awards outstanding 97,500        
Expiration Date Sep. 30, 2021