Quarterly report pursuant to Section 13 or 15(d)

Stock options and warrants (Schedule of Award Activity) (Details)

v3.5.0.2
Stock options and warrants (Schedule of Award Activity) (Details) - USD ($)
9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Stock Incentive Plan [Member]    
Shares Underlying Options    
Outstanding, beginning 332,560  
Granted 227,000  
Exercised
Forfeited (25,445) (27,178)
Outstanding, ending 534,115  
Exercisable 355,403  
Weighted Average Exercise Price    
Outstanding, beginning $ 35.36  
Granted 2.89  
Exercised  
Forfeited 36.30  
Outstanding, ending 21.55  
Exercisable $ 30.61  
Weighted Average Remaining Contractual Term    
Outstanding 7 years 10 months 24 days  
Exercisable 7 years  
Aggregate Intrinsic Value    
Outstanding $ 31,780  
Exercisable $ 8,085  
Nonqualified [Member]    
Shares Underlying Options    
Outstanding, beginning 432,003  
Granted 95,000
Exercised  
Forfeited  
Outstanding, ending 527,003  
Exercisable 432,003  
Weighted Average Exercise Price    
Outstanding, beginning $ 15.47  
Granted 3.78  
Exercised  
Forfeited  
Outstanding, ending 13.36  
Exercisable $ 15.47  
Weighted Average Remaining Contractual Term    
Outstanding 3 years  
Exercisable 1 year 6 months  
Aggregate Intrinsic Value    
Outstanding  
Exercisable