Note 3 - INVESTMENT SECURITIES (Details) $ in Millions	9 Months Ended
Sep. 30, 2022 USD ($) item issuer state security	Dec. 31, 2021 USD ($) state issuer
Number of securities \| security	701
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions \| item	639
Aggregate losses of securities (as a percent)	10.46%
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions, greater than or equal to one year \| item	30
Number Of Charters Owning Municipal Securities \| item	4
Revenue Bonds
Number of issuers \| issuer	2
Percentage threshold	5.00%
Municipal securities \| General Obligation Bonds
Number of issuers	119	113
Other investments \| $		$ 114.5
Number of states holding investments \| state	22	20
Municipal securities \| General Obligation Bonds \| Minimum
Other investments \| $	$ 5.0	$ 5.0
Municipal securities \| General Obligation Bonds \| Aggregate Fair Value Exceeding 5 Million [Member]
Number of states holding investments \| state	8	7
Municipal securities \| Revenue Bonds
Number of issuers \| issuer	182	165
Other investments \| $	$ 588.6	$ 575.0
Number of states holding investments \| state	29	28
Municipal securities \| Revenue Bonds \| Minimum
Other investments \| $	$ 5.0	$ 5.0
Municipal securities \| Revenue Bonds \| Aggregate Fair Value Exceeding 5 Million [Member]
Number of states holding investments \| state	12	13

The aggregate depreciation from amortized cost basis as a percent.

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- Definition

The number of the company's that own the company's municipal securities.

+ References

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- Definition

Number of issuers of debt securities.

+ References

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- Definition

Number of securities.

+ References

No definition available.

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- Definition

Represents the number of states investments are held in.

+ References

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- Definition

Percentage threshold of stockholders' equity which general obligation or revenue bonds market value of any single issuer does not exceed.

+ References

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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455

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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922888-210455

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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