Quarterly report pursuant to Section 13 or 15(d)

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

v2.4.0.8
Stock options and warrants (Schedule of Award Activity) (Details) (USD $)
3 Months Ended
Mar. 31, 2014
Stock Incentive Plan [Member]
 
Shares Underlying Options  
Outstanding, beginning 1,218,265
Granted 652,100
Exercised   
Forfeited (23,605)
Outstanding, ending 1,846,760
Exercisable 1,089,222
Weighted Average Exercise Price  
Outstanding, beginning $ 8.70
Granted $ 2.28
Exercised   
Forfeited $ 33.35
Outstanding, ending $ 6.12
Exercisable $ 8.74
Weighted Average Remaining Contractual Term  
Outstanding 8 years 9 months 18 days
Exercisable 8 years 2 months 12 days
Aggregate Intrinsic Value  
Outstanding $ 782,342
Exercisble 485,192
Nonqualified [Member]
 
Shares Underlying Options  
Outstanding, beginning 4,622,505
Granted   
Exercised (1,161,570)
Forfeited   
Outstanding, ending 3,460,935
Weighted Average Exercise Price  
Outstanding, beginning $ 1.82
Granted   
Exercised $ 1.36
Forfeited   
Outstanding, ending $ 1.97
Weighted Average Remaining Contractual Term  
Outstanding 4 years
Aggregate Intrinsic Value  
Outstanding $ 3,676,206