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Note 5. Stock-Based Compensation (Detail) - Fair Value Assumptions of Option Awards	9 Months Ended
	Sep. 30, 2012
Risk-free rate	0.41%
Expected dividends	0.00%
Minimum [Member]
Expected volatility	37.90%
Expected term (in years)	3 years 73 days
Maximum [Member]
Expected volatility	54.50%
Expected term (in years)	3 years 109 days

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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