Note 10 - Borrowed Funds (Details Textual) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2024	Dec. 31, 2023
Advance from Federal Home Loan Bank	$ 60,000	$ 540,000
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds	7,290,000	6,600,000
Debt Securities, Available-for-Sale	1,508,356	1,604,570
Junior Subordinated Debt [Member]
Junior Subordinated Notes, Noncurrent	$ 119,100	$ 119,100
Debt Instrument, Interest Rate, Effective Percentage	7.89%	7.54%
Debt Instrument, Term (Year)	30 years
Mature in September 2024 [Member]
Advance from Federal Home Loan Bank	$ 60,000
Federal Home Loan Bank Securities [Member] \| Asset Not Pledged as Collateral [Member]
Debt Securities, Available-for-Sale	1,490,000	$ 1,470,000
Over-night Borrowings [Member]
Advance from Federal Home Loan Bank	0	0
Non Overnight Borrowings [Member]
Advance from Federal Home Loan Bank	$ 60,000	$ 540,000
Federal Home Loan Bank, Advance, Branch of FHLBank, Interest Rate	5.08%	5.64%

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Rate of interest applicable on advance from Federal Home Loan Bank (FHLBank).

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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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, excluding current portion.

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