Note 5 - Variable Interest Entities (Details Textual)  | 
6 Months Ended | 
|---|---|
Jun. 30, 2023  | |
| Rubicon LLC [Member] | |
| Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage | 50.00% | 
| Arabian Amines Company [Member] | |
| Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage | 50.00% | 
| X | ||||||||||
- Definition Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
  | 
| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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