Note 6 - Mezzanine Equity - Share Activity (Details) - Series D Preferred Stock [Member] - shares	3 Months Ended	6 Months Ended	9 Months Ended
Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2021
Total shares (in shares)	22,958	22,757	22,863	22,757	22,863
Shares converted (in shares)	(242)	(50)	(354)
Shares issued (in shares)	249	251	248
Total shares (in shares)	22,965	22,958	22,757	22,965	22,965

The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4332-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=123431023&loc=d3e4304-108586

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