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Note 14 - Financial Derivatives (Details Textual) - USD ($) $ in Thousands |  | 3 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | ---
May 31, 2014 | Mar. 31, 2025 | Dec. 31, 2022 | Dec. 31, 2024 | Mar. 31, 2024
Junior Subordinated Notes, Total | $ 119,100 |  |  |  |
Derivative Asset, Statement of Financial Position [Extensible Enumeration] |  |  |  | Other Assets |
Derivative Liability, Statement of Financial Position [Extensible Enumeration] |  |  |  | Other Liabilities |
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative Outstanding, Notional Amount | $ 119,100 | $ 723,500 |  | $ 680,500 |
Derivative, Notional Amount |  | 27,900 |  | 32,700 |
Derivative Original Maturity (Year) | 10 years |  |  |  |
Deferred Gain on Early Termination of Derivative |  |  | $ 4,000 |  |
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member] | Central Counterparties (CCP) [Member] |  |  |  |  |
Derivative, Notional Amount |  | 0 |  | $ 0 |
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative, Notional Amount |  | 788,304 |  |  | $ 875,117
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Central Counterparties (CCP) [Member] |  |  |  |  |
Derivative, Notional Amount |  | 572,400 |  |  |
Derivative, Loss on Derivative |  | 3,200 |  |  |
Interest Rate Contract [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] |  |  |  |  |
Derivative Outstanding, Notional Amount |  | 74,800 |  |  |
Derivative, Notional Amount |  | $ 2,500 |  |  |
Interest Rate Contract [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Minimum [Member] |  |  |  |  |
Derivative, Term of Contract (Year) |  | 3 years |  |  |
Interest Rate Contract [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Maximum [Member] |  |  |  |  |
Derivative, Term of Contract (Year) |  | 10 years |  |  |
Loans Receivable with Partial-term Hedging Designation [Member] |  |  |  |  |
Hedged Asset, Fair Value Hedge |  | $ 713,500 |  |  |
Derivative, Loss on Derivative |  | 3,600 |  |  |
Loan, Notational Amount |  | 1,160,000 |  |  |
Derivative, Gain on Derivative |  | $ 4,900 |  |  |

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