Note 3 - Securities - Continuous Unrealized Loss Position (Details) - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	$ 33,945,000	$ 30,244,000
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	98,000	471,000
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	69,217,000	72,592,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	3,088,000	5,184,000
Debt securities available-for-sale, continuous loss position, fair value	103,162,000	102,836,000
Debt securities available-for-sale, continuous loss position, unrealized losses	3,186,000	5,655,000
US Treasury Securities [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	0	0
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	0	0
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	0	248,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	0	1,000
Debt securities available-for-sale, continuous loss position, fair value	0	248,000
Debt securities available-for-sale, continuous loss position, unrealized losses	0	1,000
US Government Agencies Debt Securities [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	25,559,000	11,650,000
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	59,000	235,000
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	7,597,000	10,169,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	84,000	192,000
Debt securities available-for-sale, continuous loss position, fair value	33,156,000	21,819,000
Debt securities available-for-sale, continuous loss position, unrealized losses	143,000	427,000
Taxable Municipal Notes [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	2,848,000	0
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	12,000	0
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	4,675,000	5,631,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	318,000	511,000
Debt securities available-for-sale, continuous loss position, fair value	7,523,000	5,631,000
Debt securities available-for-sale, continuous loss position, unrealized losses	330,000	511,000
Nontaxable Municipal Notes [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	499,000	6,646,000
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	1,000	96,000
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	42,301,000	43,673,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	2,315,000	3,807,000
Debt securities available-for-sale, continuous loss position, fair value	42,800,000	50,319,000
Debt securities available-for-sale, continuous loss position, unrealized losses	2,316,000	3,903,000
Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	5,039,000	11,450,000
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	26,000	140,000
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	11,697,000	9,492,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	289,000	516,000
Debt securities available-for-sale, continuous loss position, fair value	16,736,000	20,942,000
Debt securities available-for-sale, continuous loss position, unrealized losses	315,000	656,000
Corporate Debt Securities [Member]
Debt securities available-for-sale, continuous loss position, less than 12 months, fair value	0	498,000
Debt securities available-for-sale, continuous loss position, less than 12 months, unrealized losses	0	0
Debt securities available-for-sale, continuous loss position, more than 12 months, fair value	2,947,000	3,379,000
Debt securities available-for-sale, continuous loss position, more than 12 months, unrealized losses	82,000	157,000
Debt securities available-for-sale, continuous loss position, fair value	2,947,000	3,877,000
Debt securities available-for-sale, continuous loss position, unrealized losses	$ 82,000	$ 157,000