XML 25 R32.htm IDEA: XBRL DOCUMENT

Stockholders' Equity (Weighted Average Assumptions Used in Estimation of Fair Value of Option Awards) (Details)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Stockholders' Equity [Abstract]
Risk free interest rate	1.27%	1.23%
Volatility factor	69.90%	75.40%
Dividend yield	0.00%	0.00%
Expected option life (years)	6 years 3 months	6 years 3 months
Forfeiture rate	1.00%	1.00%

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.

+ References+ Details