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Note 7 - Stock-Based Compensation (Detail) - Weighted Average Fair Value Assumptions	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Expected dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate	0.67%	1.80%	1.74%
Expected volatility	58.60%	57.20%	67.70%
Expected life of option (years)	4 years 292 days	5 years	5 years 6 months

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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