| Note 10 - Leases - Balance Sheet Classification (Details) - USD ($) | Mar. 31, 2021 | Dec. 31, 2020 | 
|---|---|---|
| Current lease liabilities | $ 304,262 | $ 294,951 | 
| Noncurrent lease liabilities | 209,439 | $ 296,006 | 
| Present value of operating lease liabilities | 513,701 | |
| Other Current Liabilities [Member] | ||
| Current lease liabilities | 304,262 | |
| Other Noncurrent Liabilities [Member] | ||
| Noncurrent lease liabilities | $ 209,439 | 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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