Note 10 - Fair Value Measurements - Estimated Fair Values of Financial Instruments (Details) - USD ($)	Sep. 30, 2025	Dec. 31, 2024
Debt securities available-for-sale	$ 223,633,000	$ 116,053,000
Marketable equity securities	518,000	268,000
Reported Value Measurement [Member]
Cash and cash equivalents	54,018,000	9,179,000
Interest-bearing time deposits	7,654,000	10,369,000
Debt securities available-for-sale	223,633,000	116,053,000
Marketable equity securities	518,000	268,000
Restricted investments in bank stock	2,780,000	2,300,000
Collateral Dependent, net	891,098,000	431,960,000
Accrued interest receivable	3,984,000	1,804,000
Bank owned life insurance	28,070,000	12,966,000
Deposits	1,105,930,000	489,529,000
Repurchase agreements	1,414,000	1,143,000
FHLB advances	8,000,000	43,050,000
Accrued interest payable	2,051,000	1,736,000
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	54,018,000	9,179,000
Interest-bearing time deposits	7,648,000	10,355,000
Debt securities available-for-sale	223,633,000	116,053,000
Marketable equity securities	518,000	268,000
Restricted investments in bank stock	2,780,000	2,300,000
Collateral Dependent, net	885,713,000	426,034,000
Accrued interest receivable	3,984,000	1,804,000
Bank owned life insurance	28,070,000	12,966,000
Deposits	1,104,683,000	489,001,000
Repurchase agreements	1,414,000	1,143,000
FHLB advances	7,967,000	42,839,000
Accrued interest payable	2,051,000	1,736,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	54,018,000	9,179,000
Interest-bearing time deposits	0	0
Debt securities available-for-sale	2,988,000	2,202,000
Marketable equity securities	518,000	268,000
Restricted investments in bank stock	0	0
Collateral Dependent, net	0	0
Accrued interest receivable	0	0
Bank owned life insurance	0	0
Deposits	0	0
Repurchase agreements	0	0
FHLB advances	0	0
Accrued interest payable	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	0
Interest-bearing time deposits	7,648,000	10,355,000
Debt securities available-for-sale	220,645,000	113,851,000
Marketable equity securities	0	0
Restricted investments in bank stock	2,780,000	2,300,000
Collateral Dependent, net	0	0
Accrued interest receivable	3,984,000	1,804,000
Bank owned life insurance	28,070,000	12,966,000
Deposits	1,104,683,000	489,001,000
Repurchase agreements	1,414,000	1,143,000
FHLB advances	7,967,000	42,839,000
Accrued interest payable	2,051,000	1,736,000
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	0
Interest-bearing time deposits	0	0
Debt securities available-for-sale	0	0
Marketable equity securities	0	0
Restricted investments in bank stock	0	0
Collateral Dependent, net	885,713,000	426,034,000
Accrued interest receivable	0	0
Bank owned life insurance	0	0
Deposits	0	0
Repurchase agreements	0	0
FHLB advances	0	0
Accrued interest payable	$ 0	$ 0