| Note 11 - Acquisition - Summary of Estimated Fair Values of Acquired Assets (Details) - USD ($) | Jun. 30, 2018 | Feb. 20, 2018 | Sep. 30, 2017 | 
|---|---|---|---|
| Goodwill | $ 4,708,511 | $ 2,570,511 | |
| Calix, Inc. [Member] | |||
| Inventories | $ 2,781,000 | ||
| Property, plant and equipment | 58,000 | ||
| Goodwill | 2,138,000 | ||
| Total Assets | 10,350,000 | ||
| Calix, Inc. [Member] | Trademarks [Member] | |||
| Finite-lived intangible assets | 563,000 | ||
| Calix, Inc. [Member] | Customer Relationships [Member] | |||
| Finite-lived intangible assets | 3,742,000 | ||
| Calix, Inc. [Member] | Certification Marks [Member] | |||
| Finite-lived intangible assets | $ 1,068,000 | 
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- Definition The amount of identifiable intangible assets recognized as of the acquisition date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition The amount of inventory recognized as of the acquisition date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition The amount of property, plant, and equipment recognized as of the acquisition date. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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