Note 5 - Fair Value of Assets and Liabilities - Assets Measured at Fair Value (Details) (Parentheticals) - USD ($)	Mar. 31, 2023	Dec. 31, 2022
Investments in securities, cost	$ 6,255,614	$ 5,802,395

Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

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