Note 3 - Investments (Details Textual) - Contingent Convertible Preferred Stock [Member]	Jun. 30, 2022 USD ($)
Series A-1 and A-2, Preferred Stock [Member]
Equity Securities without Readily Determinable Fair Value, Amount	$ 3,400,000
Series E Preferred Stock [Member]
Equity Securities without Readily Determinable Fair Value, Amount	$ 995,000

Amount of investment in equity security without readily determinable fair value.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 321
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117539-209714

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