| Note 8 - Goodwill and Patents (Details Textual) $ in Thousands | 3 Months Ended | 9 Months Ended | 
|---|---|---|
| Sep. 30, 2016  USD ($) | Jun. 30, 2017  USD ($) | |
| Goodwill, Impairment Loss | $ 0 | $ 0 | 
| Number of Patents Granted | 10 | |
| Number of Patents Pending | 10 | |
| Patents [Member] | ||
| Finite-Lived Intangible Asset, Useful Life | 20 years | 
| X | ||||||||||
| 
- Definition Represents the number of patents granted in the United States. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Represents the number of patents pending. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Details 
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