Annual report pursuant to Section 13 and 15(d)

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

v2.4.0.8
Stock options and warrants (Stock incentive plan options) (Narrative) (Details) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Share-based compensation, operating expense $ 1,437,865 $ 901,161 $ 1,336,177  
Stock Incentive Plan [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Shares authorized for plan 1,912,205 1,487,205    
Options granted 525,603 540,378 52,267  
Options granted, exercise price $ 2.06 $ 2.29 $ 19.14  
Options forfeited 15,278 47,759 20,912 1,523
Options forfeited, vested 6,086 23,283 11,402 445
Options forfeited, unvested 9,192 24,476 9,510 1,078
Options forfeited, exercise price $ 24.68 $ 61.79 $ 52.50 $ 79.50
Common stock options exercised, shares           
Fair value of options vested 1,963,000 1,486,000 2,063,000  
Expected to vest 170,000      
Unrecognized compensation cost $ 269,000      
Unrecognized compensation cost, period for recognition 1 year      
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      
Stock Incentive Plan [Member] | Independent Directors [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period 10 years      
Options granted 209,333 151,992    
Options granted, exercise price $ 2.10 $ 2.28    
Vesting period 1 year      
Stock Incentive Plan [Member] | Officers [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period 10 years      
Options granted 292,000 301,362    
Options granted, exercise price $ 2.04 $ 2.29    
Vesting period 24 months      
Stock Incentive Plan [Member] | Employees [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Expiration period 10 years      
Options granted 24,270 62,024    
Options granted, exercise price $ 2.02 $ 2.46    
Vesting period 24 months      
Stock Incentive Plan [Member] | Consultant [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Options granted   25,000    
Options granted, exercise price   $ 1.91