Note 6 - Stock Based Compensation - Summary of Activity for Stock Options (Details) - shares	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Stock options outstanding, beginning of year (in shares)	4,204,816	4,470,216
Granted (in shares)	0	0
Exercised (in shares)	(131,000)	(5,000)
Expired or Forfeited (in shares)	0	0
Stock options outstanding, end of period (in shares)	4,073,816	4,465,216

Number of share options (or share units) exercised during the current period.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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+ Details