Note 11 - Income Taxes (Details Textual)	Dec. 31, 2020 USD ($)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	$ 0
Operating Loss Carryforwards, Total	39,400,000
Portion Subject to an IRS Section 382 Limitation [Member]
Operating Loss Carryforwards, Total	$ 500,000

Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant