Note 11 - Borrowed Funds (Details Textual) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2023	Dec. 31, 2022
Advance from Federal Home Loan Bank	$ 15,000	$ 485,000
Federal Home Loan Bank, Advances, General Debt Obligations, Amount of Available, Unused Funds	7,300,000
Debt Securities, Available-for-Sale	1,508,798	1,473,348
Junior Subordinated Notes, Noncurrent	$ 119,100	$ 119,100
Junior Subordinated Debt [Member]
Debt Instrument, Interest Rate, Effective Percentage	7.41%	4.01%
Debt Instrument, Term (Year)	30 years
Federal Home Loan Bank Securities [Member] \| Asset Not Pledged as Collateral [Member]
Debt Securities, Available-for-Sale	$ 1,380,000
Mature in September 2024 [Member]
Advance from Federal Home Loan Bank	15,000
Over-night Borrowings [Member]
Advance from Federal Home Loan Bank	0	$ 150,000
Non Overnight Borrowings [Member]
Advance from Federal Home Loan Bank	$ 15,000	$ 335,000
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Interest Rate	5.54%	4.54%

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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Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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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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