Stock Based compensation (Details)	3 Months Ended
Stock Based compensation (Details)	Mar. 31, 2013	Mar. 31, 2012
Minimum percentage of Expected volatility	114.66%	125.11%
Maximum percentage of Expected volatility	131.97%	125.11%
Expected dividends percentage	0.00%	0.00%
Expected term in years	3	3
Minimum Risk free rate percentage	0.25%	0.33%
Maximum Risk free rate percentage	0.27%	0.33%