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Note 10 - Stock-based Compensation - Summary of Information Related to Options Outstanding (Details) - Mercantile Plans [Member] - $ / shares | 12 Months Ended
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Dec. 31, 2022 | Dec. 31, 2021
Minimum exercise price (in dollars per share) | $ 36.22 | $ 27.66
Maximum Exercise Price (in dollars per share) | $ 36.22 | $ 36.22
Average remaining option term (Year) | 10 months 24 days | 1 year 8 months 12 days

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- Definition The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
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- Definition The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
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- Definition Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 718 -SubTopic 10 -Subparagraph (e)(1) -Name Accounting Standards Codification -Paragraph 2 -Section 50 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480429/718-10-50-2 + Details
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- Details
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