Note 6 - Income Taxes (Details Textual) $ in Thousands  | 
 Sep. 30, 2020  
USD ($) 
 | 
|---|---|
| Deferred Tax Assets, Valuation Allowance, Total | $ 0 | 
| Domestic Tax Authority [Member] | |
| Operating Loss Carryforwards, Total | 3,600 | 
| State and Local Jurisdiction [Member] | |
| Operating Loss Carryforwards, Subject to Expiration | 2,400 | 
| Foreign Tax Authority [Member] | |
| Operating Loss Carryforwards, Subject to Expiration | $ 2,900 | 
| X | ||||||||||
- Definition Amount of operating loss carryforward subject to expiration, before tax effects, available to reduce future taxable income under enacted tax laws. No definition available. 
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| X | ||||||||||
- Definition Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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| X | ||||||||||
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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