Note 12 - Segment Information (Details Textual)  | 
12 Months Ended | 
|---|---|
Dec. 31, 2020  | |
| Number of Reportable Segments | 1 | 
| X | ||||||||||
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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