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Note 14 - Financial Derivatives (Details Textual) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
	May 31, 2014	Jun. 30, 2024	Dec. 31, 2022	Dec. 31, 2023
Junior Subordinated Notes, Total	$ 119,100
Interest Rate Swap [Member] | Cash Flow Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Outstanding, Notional Amount	$ 119,100	$ 618,400		$ 650,900
Derivative, Notional Amount		40,000		38,600
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		837,155		$ 1,156,007
Interest Rate Swap [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Central Counterparties (CCP) [Member]
Derivative, Notional Amount		533,600
Derivative, Gain on Derivative		3,600
Interest Rate Contract [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member]
Derivative Outstanding, Notional Amount		82,800
Derivative, Notional Amount		$ 4,500
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]
Derivative, Notional Amount		$ 7,100
Hedged Asset, Fair Value Hedge		754,400
Loan, Notational Amount		1,250,000
Hedged Asset, Fair Value Hedge, Portfolio Layer Method, Hedged Layer, Fair Value, Cumulative Increase (Decrease)		$ (5,800)

X

- Definition

The amount of deferred gain on early termination of derivative recognized.

+ References

No definition available.

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- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

No definition available.

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- Definition

Outstanding notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

No definition available.

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- Definition

The notational amount of a loan.

+ References

No definition available.

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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

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

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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

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- Definition

Amount of asset hedged in fair value hedging relationship.

+ References

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-Topic 815
-SubTopic 10
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-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

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- Definition

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk, in portfolio layer hedging relationship.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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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

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-Paragraph 1
-Subparagraph (SX 210.5-02(22))
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