Note 8 - Stockholders' Equity - Restricted Stock Unit Activity Under Stock-based Plans (Details) - Restricted Stock Units (RSUs) [Member] - shares |
6 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jun. 30, 2022 |
Jun. 30, 2022 |
Dec. 31, 2021 |
|
| Outstanding (in shares) | 1,685,141 | 1,436,728 | |
| Awarded (in shares) | 132,588 | 654,663 | |
| Canceled/forfeited/expired (in shares) | 0 | (406,250) | |
| Outstanding (in shares) | 1,817,729 | 1,817,729 | 1,685,141 |
| Expected to vest at June 30, 2022 (in shares) | 1,817,729 | 1,817,729 | |
| Vested at June 30, 2022 (in shares) | 1,817,729 |
| X | ||||||||||
- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Number of shares under non-option equity instrument agreements that were either cancelled or expired. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Net number of non-option equity instruments granted to participants. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| 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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