Note 9 - Fair Value Measurements - Fair Value Estimates for Financial Instruments, Excluding Financial Instruments on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Reported Value Measurement [Member]
Cash and due from banks	$ 397,284	$ 567,801
Debt securities held to maturity	799,558	819,574
Loans	685,053	714,909
Deposits	4,783,752	4,840,019
Securities sold under repurchase agreements	144,456	137,298
Estimate of Fair Value Measurement [Member]
Cash and due from banks	397,284	567,801
Debt securities held to maturity	784,304	812,580
Loans	683,792	716,439
Deposits	4,779,959	4,836,933
Securities sold under repurchase agreements	144,456	137,298
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	397,284	567,801
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	784,304	812,580
Loans	0	0
Deposits	4,718,809	4,772,998
Securities sold under repurchase agreements	144,456	137,298
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	683,792	716,439
Deposits	61,150	63,935
Securities sold under repurchase agreements	$ 0	$ 0

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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- 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

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- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
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-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/exampleRef
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Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
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- 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/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

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- 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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