XML 12 R25.htm IDEA: XBRL DOCUMENT

Stock-based Compensation (Key Weighted-Average Assumptions) (Details) (Stock Options [Member], USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Expected stock price volatility	106.40%	99.10%
Risk-free interest rate	0.80%	2.30%
Expected term	5 years 4 months 24 days	5 years 10 months 24 days
Weighted-average grant date fair-value	$ 0.24	$ 0.99

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.

+ References+ Details