Note 10 - Accrued Retirement Benefits - Accrued Retirement Benefits (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Accrued retirement benefits	$ 1,591	$ 2,508
Less current portion	140	140
Non-current portion of accrued retirement benefits	1,451	2,368
Pension Plan [Member] \| Qualified Plan [Member]
Accrued retirement benefits	0	912
Supplemental Employee Retirement Plan [Member] \| Nonqualified Plan [Member]
Accrued retirement benefits	$ 1,591	$ 1,596

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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