Note 9 - Accrued Retirement Benefits - Accrued Retirement Benefits (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Accrued retirement benefits	$ 2,157	$ 8,079
Less current portion	142	142
Non-current portion of accrued retirement benefits	2,015	7,937
Pension Plan [Member] \| Qualified Plan [Member]
Accrued retirement benefits	64	5,932
Supplemental Employee Retirement Plan [Member] \| Nonqualified Plan [Member]
Accrued retirement benefits	$ 2,093	$ 2,147

Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 45
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-URI https://asc.fasb.org/extlink&oid=123453770&loc=d3e1703-114919

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant