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Note 9 - Fair Value Measurements - Fair Value Estimates for Financial Instruments, Excluding Financial Instruments on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Reported Value Measurement [Member]
Cash and due from banks	$ 659,268	$ 601,494
Debt securities held to maturity	826,505	844,634
Loans	729,720	805,520
Deposits	4,793,179	5,011,850
Securities sold under repurchase agreements	133,651	120,322
Estimate of Fair Value Measurement [Member]
Cash and due from banks	659,268	601,494
Debt securities held to maturity	817,188	807,838
Loans	730,365	795,849
Deposits	4,788,614	5,007,644
Securities sold under repurchase agreements	133,651	120,322
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	659,268	601,494
Debt securities held to maturity	0	0
Loans	0	0
Deposits	0	0
Securities sold under repurchase agreements	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and due from banks	0	0
Debt securities held to maturity	817,188	807,838
Loans	0	0
Deposits	4,721,941	4,929,612
Securities sold under repurchase agreements	133,651	120,322
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and due from banks	0	0
Debt securities held to maturity	0	0
Loans	730,365	795,849
Deposits	66,673	78,032
Securities sold under repurchase agreements	$ 0	$ 0

X

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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X

- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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X

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

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X

- Definition

Fair value portion of securities that an entity sells and agrees to repurchase at a specified date for a specified price.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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X

- Definition

This item represents the total of all debt securities grouped by maturity dates, at fair value, which are categorized as held-to-maturity.

+ References

No definition available.

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