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Common Stock (Details)	6 Months Ended
Common Stock (Details)	Jun. 30, 2012	Jun. 30, 2011
Common Stock [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	116.00%	104.00%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%
Fair Value Assumptions, Risk Free Interest Rate	0.00%	0.00%

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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