Quarterly report pursuant to Section 13 or 15(d)

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

v3.4.0.3
Stock options and warrants (Stock incentive plan options) (Narrative) (Details) - USD ($)
3 Months Ended
Mar. 31, 2016
Mar. 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 Incentive Plan [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Incentive stock options exercised to purchase common shares    
Options granted    
Options granted, exercise price      
Options forfeited 7,382 21,668    
Options expired 3,762 1,876    
Options forfeited, unvested 3,620 19,792    
Options forfeited, exercise price $ 20.98      
Options expired, exercise price 26.61 $ 193.36    
Options forfeited, unvested, exercise price $ 15.13 $ 16.48    
Fair value of options vested $ 127,000 $ 234,000    
Expected to vest 16,000      
Unrecognized compensation cost $ 128,000      
Stock Incentive Plan [Member] | Directors, Employees and Consultants [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Dividend yield   0.00%    
Expected price volatility   93.00%    
Risk free interest rate   1.39%    
Expected term   5 years    
Stock Incentive Plan [Member] | Independent Directors [Member]        
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Vesting period   1 year    
Options granted   43,000    
Options granted, exercise price   $ 15.12    
Expiration period   10 years    
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   98,813    
Options granted, exercise price   $ 15.12    
Expiration period   10 years    
Vesting rate   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      
Unrecognized compensation cost, period for recognition 1 year