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Note 9 - Dividends (Details Textual) - USD ($) $ / shares in Units, $ in Thousands | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | Sep. 30, 2019 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Nov. 30, 2020 | Aug. 31, 2019
Payments of Ordinary Dividends, Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 52,366 | $ 42,089 | $ 5,459 |  |
Line Of Credit Facility Dividend Restrictions Percentage Of Net Income Limit |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 25.00% | 25.00%
Line of Credit Facility, Waiver to Pay Dividends, Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 60,000 | $ 65,000
Paid Quarterly [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments of Ordinary Dividends, Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 52,400 |  |  |  |
Common Stock, Dividends, Per Share, Declared (in dollars per share) | $ 0.50 |  | $ 0.04 | $ 0.04 | $ 0.027 | $ 0.027 | $ 0.02 | $ 0.02 | $ 0.02 | $ 0.02 | $ 0.017 | $ 0.017 | $ 0.017 | $ 0.017 |  |  |  |  |
Special Dividend [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common Stock, Dividends, Per Share, Declared (in dollars per share) |  | $ 0.433 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition The maximum amount for a waiver to pay for dividends as part of a line of credit facility. + References No definition available. + Details
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- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 + Details
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- Definition Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585 + Details
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