Note 5 - Allowance for Credit Losses (Details Textual)	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Financing Receivable, Reviewed for Loan Grade, Percentage of Dollar Volume	50.00%		50.00%
Financing Receivable, Reviewed for Loan Grade, Minimum Commitment	$ 1,000,000		$ 1,000,000
Financing Receivable, Reviewed for Loan Grade, Past Due Period (Day)			90 days
Financing Receivable, Revolving, Converted to Term Loan	0		$ 0		$ 0
Financing Receivable, Accrued Interest, Writeoff	0	$ 0	0	$ 0
Financing Receivable, Modified, Commitment to Lend	$ 0		$ 0
Financing Receivable, Modified in Period, Number of Loans	0	0	0	0
Unfunded Loan Commitment [Member]
Off-Balance-Sheet, Credit Loss, Liability	$ 277,000	$ 318,000	$ 277,000	$ 318,000	$ 377,000	$ 266,000
Commercial, Agricultural and State and Political Relationships [Member]
Financing Receivable, Annually Reviewed for Loan Grade, Minimum Amount	$ 500,000		$ 500,000