Note 6 - Inventories - Inventories (Details) - USD ($) $ in Thousands  | 
Sep. 30, 2023  | 
Dec. 31, 2022  | 
|---|---|---|
| Raw materials | $ 4,271 | $ 3,837 | 
| Work in progress | 365 | 487 | 
| Finished goods | 851 | 863 | 
| Inventories | $ 5,487 | $ 5,187 | 
| X | ||||||||||
- Definition Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
  | 
| X | ||||||||||
- Definition Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/exampleRef 
  | 
| X | ||||||||||
- Definition Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
  | 
| X | ||||||||||
- Definition Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
  |