Note 4 - Loans and Allowance for Credit Losses - Components of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Beginning balance	$ 4,487	$ 4,405	$ 4,560	$ 4,548	$ 4,548
Provision for (recovery of) credit losses	327	0	595	0
Charge-offs	(290)	0	(646)	(156)	(162)
Charge-offs	(290)	0	(646)	(156)	(162)
Recoveries	6	6	21	19	24
Ending balance	4,530	4,411	4,530	4,411	4,560
Held-to-Maturity Securities [Member]
Beginning balance	81	127	60	36	36
Provision for (recovery of) credit losses	(2)	(90)	19	1
Charge-offs	0	0	0	0
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	79	37	79	37	60
Loans [Member]
Beginning balance	4,233	4,082	4,260	4,284	4,284
Provision for (recovery of) credit losses	308	103	622	44
Charge-offs	(290)	0	(646)	(156)
Charge-offs	(290)	0	(646)	(156)
Recoveries	6	6	21	19
Ending balance	4,257	4,191	4,257	4,191	4,260
Unfunded Loan Commitment [Member]
Beginning balance		196		228	228
Provision for (recovery of) credit losses		(13)		(45)
Charge-offs		0		0
Charge-offs		0		0
Recoveries		0		0
Ending balance		$ 183		$ 183
Unfunded Loan Commitments [Member]
Beginning balance	173		240
Provision for (recovery of) credit losses	21		(46)
Charge-offs	0		0
Charge-offs	0		0
Recoveries	0		0
Ending balance	$ 194		$ 194		$ 240