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Note 14 - Termination of Deferred Compensation Plan (Details Textual) - 2015 Equity Incentive Plan [Member] $ in Millions | 12 Months Ended
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Dec. 31, 2020 USD ($) shares
Deferred Compensation Arrangement with Individual, Shares Issued (in shares) | shares | 394,056
Deferred Compensation Arrangement with Individual, Compensation Expense | $ | $ 6.8

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- Definition The compensation expense recognized during the period pertaining to the deferred compensation arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 710 -SubTopic 10 -Section 30 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363 + Details
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- Definition Number of shares issued pursuant to the terms of a deferred compensation arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (l) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
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Period Type: | duration

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- Details
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Balance Type: |
Period Type: |