Note 3 - Loans Receivable (Details Textual)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Financing Receivable, Unamortized Loan Cost (Fee) and Purchase Premium (Discount)	$ 19,500,000		$ 19,500,000		$ 14,800,000
Financing Receivable, Accrued Interest, after Allowance for Credit Loss	6,500,000		6,500,000		6,000,000
Financing Receivable, Nonaccrual, Interest Income	1,000	$ 19,000	35,000	$ 52,000
Financing Receivable, Individually Evaluated for Credit Loss	31,800,000		31,800,000		20,000,000
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment	2,600,000		$ 2,600,000		$ 165,000
Commercial Portfolio Segment [Member] | Payment Deferral [Member]
Financing Receivable, Modified, Number of Contracts			1		1
Financing Receivable, Modified, Accumulated	17,000		$ 17,000		$ 119,000
Valuation Technique, Discounted Cash Flow [Member]
Financing Receivable, Individually Evaluated for Credit Loss	4,600,000		4,600,000		2,500,000
Valuation Technique, Underlying Value of Collateral [Member]
Financing Receivable, Individually Evaluated for Credit Loss	$ 27,200,000		$ 27,200,000		$ 17,500,000