Note 1 - Organization and Significant Accounting Policies - Summary of Earnings (Loss) Per Share (Details) - shares	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Basic weighted-average shares (in shares)	30,348,000	30,289,000
Conversion of unsecured loan notes (in shares)	0	0
Unexercised options and unvested restricted stock units (in shares)	0	0
Diluted weighted-average shares (in shares)	30,348,000	30,289,000

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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