Note 8 - Stock-based Incentive Plans - Warrants Activity (Details) - Stock Warrants [Member] - $ / shares |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Outstanding, number of warrants (in shares) | 964,000 | |
| Outstanding, exercise price per shares, warrants (in dollars per share) | $ 10.26 | $ 10.02 |
| Expired, number of warrants (in shares) | (183,000) | |
| Expired, exercise price per shares, warrants (in dollars per share) | $ 9.00 | |
| Outstanding, number of warrants (in shares) | 781,000 | |
| Outstanding, remaining contractual term, warrants (Year) | 4 years 6 months 21 days | |
| Vested and exercisable, number of warrants (in shares) | 781,000 | |
| Vested and exercisable, weighted average exercise price per share, warrants (in dollars per share) | $ 10.26 | |
| Vested and exercisable,, remaining contractual term, warrants (Year) | 4 years 6 months 21 days |
| X | ||||||||||
- Definition Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible equity instruments other than options. No definition available.
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| X | ||||||||||
- Definition Number of fully vested and expected to vest exercisable non-option equity instruments that may be converted into shares under plan. No definition available.
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| X | ||||||||||
- Definition Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible non-option equity instruments. No definition available.
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| X | ||||||||||
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock equity instruments other than options plan. No definition available.
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| X | ||||||||||
- Definition Weighted average price at which grantees could have acquired the underlying shares with respect to non-option equity instruments that expired. No definition available.
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| X | ||||||||||
- Definition Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Number of shares under non-option equity instrument agreements for which rights to exercise lapsed. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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