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Note 2. Long-Term Incentive Plans (Detail) - Stock Option Fair Value Assumptions (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Expected volatility	73.18%	70.72%	71.46%	71.11%
Risk-free interest rate	0.52%	1.42%	0.56%	1.79%
Expected dividend yield	0.00%	0.00%	0.00%	0.00%
Expected life (in years)	3 years 277 days	6 years	3 years 83 days	6 years
Estimated fair value per option granted (in Dollars per share)	$ 0.55	$ 1.32	$ 0.70	$ 1.34

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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