Note 9 - Stock Based Compensation - Restricted Stock Activity (Details) - $ / shares |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2021 |
Dec. 31, 2020 |
|
| Non-vested, shares (in shares) | 36,828 | 30,205 |
| Non-vested, weighted average grant date fair value (in dollars per share) | $ 40.11 | $ 35.63 |
| Granted, shares (in shares) | 17,716 | 13,243 |
| Granted, weighted average grant date fair value (in dollars per share) | $ 40.50 | $ 44.30 |
| Vested, shares (in shares) | (9,993) | (6,400) |
| Vested, weighted average grant date fair value (in dollars per share) | $ 36.71 | $ 27.50 |
| Forfeited, shares (in shares) | 0 | (220) |
| Forfeited, weighted average grant date fair value (in dollars per share) | $ 0 | $ 43.65 |
| Non-vested, shares (in shares) | 44,551 | 36,828 |
| Non-vested, weighted average grant date fair value (in dollars per share) | $ 41.03 | $ 40.11 |
| X | ||||||||||
- Definition Gross number of share options (or share units) granted during the period. No definition available.
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| X | ||||||||||
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Number of non-vested options outstanding. No definition available.
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| X | ||||||||||
- Definition Number of non-vested options forfeited. No definition available.
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| X | ||||||||||
- Definition Weighted average grant-date fair value of non-vested options forfeited. No definition available.
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| X | ||||||||||
- Definition Weighted average grant-date fair value of non-vested options outstanding. No definition available.
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| X | ||||||||||
- Definition Number of options vested. No definition available.
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| X | ||||||||||
- Definition Weighted average grant-date fair value of options vested. No definition available.
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