Note 2 - Stockholders' Equity and Stock-based Compensation - Unvested Restricted Stock and Deferred Stock (Details) - Employee Deferred Stock Award [Member] - $ / shares	3 Months Ended	12 Months Ended
Mar. 31, 2023	Dec. 31, 2022
Non-Vested Balance (in shares)	41,200
Non-Vested Balance, weighted average fair value per share (in dollars per share)	$ 16.62
Granted (in shares)	19,020	18,600
Granted, weighted average fair value per share (in dollars per share)	$ 25.52	$ 21.62
Vested (in shares)	(20,050)
Vested, weighted average fair value per share (in dollars per share)	$ 14.33
Forfeited (in shares)	(1,950)
Forfeited, weighted average fair value per share (in dollars per share)	$ 19.07
Non-Vested Balance (in shares)	38,220	41,200
Non-Vested Balance, weighted average fair value per share (in dollars per share)	$ 22.13	$ 16.62

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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.

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