Note 9 - Stock Compensation Plans - RSU Activity (Details) (Parentheticals) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Share price on grant date (in dollars per share)	$ 2.46	$ 0.90
Share price on vesting date (in dollars per share)	$ 2.27	$ 0.92

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration