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Note 15 - Financial Derivatives (Details Textual) - USD ($) $ in Thousands |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
May 31, 2014 | Sep. 30, 2022 | Sep. 30, 2023 | Sep. 30, 2022 | Dec. 31, 2022
Junior Subordinated Notes, Total | $ 119,100 |  |  |  |
Loans Receivable with Partial-term Hedging Designation [Member] |  |  |  |  |
Derivative, Notional Amount |  |  | $ 21,100 |  |
Hedged Asset, Fair Value Hedge |  |  | 768,100 |  |
Loan, Notational Amount |  |  | 1,300,000 |  |
Hedged Asset, Fair Value Hedge, Portfolio Layer Method, Hedged Layer, Fair Value, Cumulative Increase (Decrease) |  |  | 19,900 |  |
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative Outstanding, Notional Amount | $ 119,100 |  | 642,100 |  | $ 595,400
Derivative, Notional Amount |  |  | 56,000 |  | 50,000
Derivative Original Maturity (Year) | 10 years |  |  |  |
Deferred Gain on Early Termination of Derivative |  |  |  |  | 4,000
Derivative, Gain on Derivative |  | $ 138 |  | $ 1,300 |
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Central Counterparties (CCP) [Member] |  |  |  |  |
Derivative, Notional Amount |  |  |  |  | $ 205,600
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative, Notional Amount |  | $ 874,034 | $ 857,341 | $ 874,034 |
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Minimum [Member] |  |  |  |  |
Derivative, Term of Contract (Year) |  |  | 3 years |  |
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Maximum [Member] |  |  |  |  |
Derivative, Term of Contract (Year) |  |  | 10 years |  |
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Central Counterparties (CCP) [Member] |  |  |  |  |
Derivative, Notional Amount |  |  | $ 547,500 |  |
Derivative, Gain on Derivative |  |  | 13,900 |  |
Interest Rate Contract [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative Outstanding, Notional Amount |  |  | 89,300 |  |
Derivative, Notional Amount |  |  | $ 6,300 |  |

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References No definition available. + Details
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- Definition Amount of increase in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4A + Details
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- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
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