Note 8 - Fair Value Assumptions of Options Granted (Details)  | 
12 Months Ended | |
|---|---|---|
Dec. 31, 2015  | 
Dec. 31, 2014  | 
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| Minimum [Member] | ||
| Expected volatility | 44.00% | 43.00% | 
| Expected term (years) | 5 years 182 days | 5 years 182 days | 
| Risk-free rate | 1.54% | 0.07% | 
| Maximum [Member] | ||
| Expected volatility | 50.00% | 46.00% | 
| Expected term (years) | 7 years | 7 years 182 days | 
| Risk-free rate | 2.01% | 2.05% | 
| Forfeiture rate | 20.00% | |
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- Definition Represents the forfeiture rate in determine the fair value for the share-based compensation. No definition available. 
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- Definition 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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- Details 
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