Note 7 - Investments in Equity Securities (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Equity Securities, FV-NI, Unrealized Gain	$ 233,644	$ 585,107
Equity Securities, FV-NI, Unrealized Loss	0	0
Equity Securities, FV-NI, Realized Gain	152,748	0
Equity Securities, FV-NI, Realized Loss	$ 0	$ 0

Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=120269885&loc=SL75117546-209714

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Amount of realized loss from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized gain on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized loss on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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