Fair value assumptions (Details) - $ / shares	9 Months Ended
Fair value assumptions (Details) - $ / shares	Sep. 30, 2015	Sep. 30, 2014
Warrants weighted Average Assumptions
Expected volatility Minimum,	128.36%	113.93%
Expected volatility Maximum,	155.43%	138.05%
Expected dividends,	0.00%	0.00%
Expected term mimimum(years),	$ 3	$ 3
Expexted term maximum(Years),	5	5
Risk free rate mimimum,	0.51%	0.41%
Risk free rate maximum,	1.75%	0.59%