| Note 6 - Property, Equipment and Leasehold Improvements (Details Textual) - USD ($) $ in Thousands | 3 Months Ended | |
|---|---|---|
| Mar. 31, 2024 | Mar. 31, 2023 | |
| Depreciation | $ 90 | $ 120 | 
| X | ||||||||||
| 
- Definition The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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