Note 15 - Income Taxes - Components of Deferred Tax Assets (Details) - USD ($) |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Deferred tax assets: | ||
| Net operating loss carryforwards | $ 34,365,098 | $ 31,966,658 |
| R&D credit carryforwards | 9,301,709 | 9,150,580 |
| AMT credit carryforward | 310,620 | |
| Stock compensation | 419,654 | 382,016 |
| Intangibles | 616,926 | 610,783 |
| Disallowed interest expense | 852,338 | 857,648 |
| Temporary differences | 267,312 | 333,728 |
| Deferred tax assets before valuation allowance | 45,823,037 | 43,612,033 |
| Valuation allowance | (45,823,037) | (43,301,413) |
| Net deferred tax assets | $ 310,620 |
| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to disallowed interest expense. No definition available.
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to research and development tax credit carryforwards. No definition available.
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to temporary differences. No definition available.
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from intangible assets including goodwill. No definition available.
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, without jurisdictional netting. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible alternative minimum tax credit carryforwards. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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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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