Fair value of warrants was estimated on the date of grant (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Expected volatility minimum	114.66%	60.75%
Expected volatility maximum	125.11%	77.05%
Expected dividends	0.00%	0.00%
Expected term in years	3	3
Risk free rate minimum	0.25%	0.25%
Risk free rate maximum	0.33%	3.10%