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Note 10 - Derivative Financial Instruments - Balance Sheet Information (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
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Derivative financial instruments | $ 1,662 | $ 669
TBA and Other Forward MBS [Member] | Long [Member] | Investments -Trading [Member] |  |
Derivative financial instruments | 13,717 | 3,686
TBA and Other Forward MBS [Member] | Short [Member] | Trading Securities Sold, Not Yet Purchased [Member] |  |
Derivative financial instruments | (11,822) | (3,017)
Other Extended Settlement Trade [Member] | Long [Member] | Investments -Trading [Member] |  |
Derivative financial instruments |  |
Other Extended Settlement Trade [Member] | Short [Member] | Trading Securities Sold, Not Yet Purchased [Member] |  |
Derivative financial instruments |  |
Derivatives, Publicity Traded Options [Member] | Short [Member] | Other Investments Sold, Not Yet Purchased [Member] |  |
Derivative financial instruments | $ (233) |

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- Definition Fair value of the assets less the liabilities of a derivative or group of derivatives. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611 + Details
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