Note 2 - INVESTMENT SECURITIES (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2023 USD ($) issuer state security item	Jun. 30, 2023 USD ($) item issuer state security	Dec. 31, 2022 USD ($) state issuer
Number of securities | security	641	641
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions | item	563	563
Aggregate losses of securities (as a percent)	11.00%	11.00%
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions, greater than or equal to one year | item	397	397
Gain on sale	$ 12	$ 56
Number Of Charters Owning Municipal Securities | item		4
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 989	$ 989
General Obligation Bonds
Number of issuers | issuer	85	85	118
Other investments	$ 89,600	$ 89,600	$ 110,600
Number of states holding investments | state	18	18	22
General Obligation Bonds | Aggregate Fair Value Exceeding 5 Million
Number of states holding investments	7	7	7
General Obligation Bonds | Aggregate Fair Value Exceeding 5 Million | Minimum
Other investments	$ 5,000	$ 5,000	$ 5,000
Revenue Bonds
Number of issuers | issuer	166	166	181
Other investments	$ 616,100	$ 616,100	$ 617,200
Number of states holding investments | state	30	30	29
Revenue Bonds | Aggregate Fair Value Exceeding 5 Million
Number of states holding investments | state	13	13	12
Revenue Bonds | Aggregate Fair Value Exceeding 5 Million | Minimum
Other investments	$ 5,000	$ 5,000	$ 5,000
Revenue Bonds | Aggregate Book Or Market Value Exceeded 5% of The Company Equity [Member]
Number of issuers | issuer	2	2	2
Percentage threshold	5.00%	5.00%	5.00%
Other securities
Debt Securities, Available-for-Sale, Allowance for Credit Loss	$ 989	$ 989