Annual report pursuant to Section 13 and 15(d)

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

v3.7.0.1
Stock options and warrants (Schedule of Fair Value Assumptions) (Details) - Stock Incentive Plan [Member]
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Dividend yield 0.00% 0.00%
Expected price volatility, minimum 99.00%  
Expected price volatility, maximum 100.00%  
Expected price volatility   93.00%
Risk free interest rate, minimum 1.20%  
Risk free interest rate, maximum 1.83%  
Risk free interest rate   1.39%
Expected term 5 years 5 years