Note 3 - Investment Securities (Details Textual) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss	$ 281,100			$ 281,100		$ 302,500
Debt Securities, Held-to-Maturity, Accrued Interest, after Allowance for Credit Loss	120,200			120,200		122,000
Proceeds from sale of securities Available for sale	0			0	$ 521,000
Gain (Loss) from Hedged Firm Commitment Not Qualifying as Fair Value Hedge, Net	0	$ 94,000	$ 0	94,000	$ 0
Asset Pledged as Collateral [Member] | Government Deposits and Securities Sold Under Repurchase Agreement [Member]
Debt Securities	$ 21,500,000			$ 21,500,000		$ 26,300,000