Note 9 - Share-based Compensation - Shares Authorized, Available for Future Grant and Outstanding Under Each Plan (Details)	Jun. 30, 2022 shares
Authorized (in shares)	1,950,000
Available (in shares)	1,232,633
Outstanding (in shares)	315,368
The 2016 Plan [Member]
Authorized (in shares)	1,300,000
Available (in shares)	944,938
Outstanding (in shares)	247,868
2014 Directors Plan [Member]
Authorized (in shares)	650,000
Available (in shares)	287,695
Outstanding (in shares)	12,000
The 2005 Plan [Member]
Available (in shares)	0
Outstanding (in shares)	49,500
The 2004 Directors Plan [Member]
Outstanding (in shares)	6,000

Number of options and equity instrument other than options outstanding.

No definition available.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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