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Note 7 - Investment Securities (Details Textual) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss		$ 6,300		$ 6,300		$ 5,500
Equity Securities, FV-NI, Unrealized Gain (Loss)		(1,400)	$ 10,700	(10,457)	$ 15,516
Equity Securities, FV-NI, Current		$ 31,488		$ 31,488		$ 40,406
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		203		203		192
Proceeds from Sale of Debt Securities, Available-for-Sale				$ 33,690	$ 0
Debt Securities, Available-for-Sale, Allowance for Credit Loss		$ 0		0
Debt Securities, Available-for-Sale, Transfer in, Allowance for Credit Loss, Expense		0		0
Pledged Investment Securities		$ 18,900		18,900		$ 134,200
Signature Bank [Member]
Debt Securities, Available-for-Sale, Realized Loss	$ 3,000
Proceeds from Sale of Debt Securities, Available-for-Sale				$ 1,400
Collateralized Mortgage-Backed Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		153		153		154
Corporate Debt Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		25		25		24
US Treasury Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		11		11		1
Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		5		5		5
US Government Corporations and Agencies Securities [Member]
Debt Securities, Available-for-Sale, Unrealized Loss Position, Number of Positions		5		5		8

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