Note 13 - Equity Plans - Stock-based Compensation Expense Recognized on Restricted Stock Units (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
RSU expense before taxes of the Plan	$ 1,297	$ 1,045	$ 1,265
RSU expense after taxes	$ 954	$ 767	$ 1,024

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration