Quarterly report pursuant to Section 13 or 15(d)

Stock options and warrants (Schedule of Fair Value Assumptions) (Details)

v2.4.0.8
Stock options and warrants (Schedule of Fair Value Assumptions) (Details) (Stock Incentive Plan [Member])
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Stock Incentive Plan [Member]
   
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Dividend yield 0.00% 0.00%
Expected price volatility, minimum 96.00% 127.00%
Expected price volatility, maximum 126.00% 128.00%
Risk free interest rate, minimum 1.52% 0.72%
Risk free interest rate, maximum 1.70% 0.76%
Expected term 5 years 5 years