Note 7 - Other Equity - Stock Option Fair Value Assumptions (Details) - USD ($) |
6 Months Ended | |
|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
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| Statement Line Items [Line Items] | ||
| Weighted average risk-free interest rate | 2.39% | 1.24% |
| Expected dividend yield | ||
| Weighted average expected volatility | 93.90% | 100.20% |
| Weighted average expected life of options (in years) | 5 | 5 |
| Weighted average grant date fair value | $ 2.14 | $ 0.81 |
| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The option life of share options granted. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The amount of an expected dividend used to calculate the fair value of share options granted. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The weighted average fair value of share options granted during the period at the measurement date. [Refer: Weighted average [member]] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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