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Note 10 - Stock Based Compensation (Detail) - Fair Value of Option Assumptions	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Risk-free interest rate	0.78%
Expected volatility	102.23%
Expected life (in years)	5 years
Expected forfeiture rate	0.00%
Expected dividend yield	0.00%
Minimum [Member]
Risk-free interest rate	0.85%	2.97%
Expected volatility	83.41%
Expected life (in years)	5 years 3 months	6 years
Expected forfeiture rate	5.00%	7.50%
Expected dividend yield	0.00%	0.00%

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.

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