Note 15 - Financial Derivatives (Details Textual) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Derivative Outstanding, Notional Amount	$ 1,160,000	$ 1,020,000
Derivative, Notional Amount	17,600	24,000
Margin Deposit Assets	17,900	12,100
Bank [Member]
Restricted Cash	2,100	4,300
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	623,678	$ 625,222
Interest Rate Contract [Member] \| Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member] \| Central Counterparties (CCP) [Member]
Derivative Outstanding, Notional Amount	623,700
Derivative, Notional Amount	570,400
Derivative, Loss on Derivative	475,000
Interest Rate Contract [Member] \| Fair Value Hedging [Member] \| Designated as Hedging Instrument [Member]
Derivative Outstanding, Notional Amount	46,700
Derivative, Notional Amount	1,700
Loans Receivable with Partial-term Hedging Designation [Member]
Derivative, Notional Amount	857,100
Hedged Asset, Fair Value Hedge	577,000
Derivative, Gain on Derivative	$ 1,100

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

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/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
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Amount of decrease in the fair value of derivatives recognized in the income statement.

+ References

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- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

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- Definition

Amount of asset hedged in fair value hedging relationship.

+ References

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- Definition

The amount of cash or securities placed with a broker or counterparty as security for a trading or derivatives securities position which was partially obtained with funds provided by the broker dealer.

+ References

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Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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