Note 10 - Income Taxes - Components of Net Deferred Tax Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax asset
Allowance for credit losses	$ 4,853	$ 5,858
Securities available for sale	79,865	107,493
State franchise taxes	4,816	3,805
Deferred compensation	3,828	4,091
Purchased assets and assumed liabilities	321	229
Post-retirement benefits	367	405
Employee benefit accruals	3,454	3,096
VISA Class B shares	343	507
Accrued liabilities	1,172	840
Premises and equipment	1,175	1,193
Lease liability	5,413	4,548
Other	69	99
Total deferred tax asset	105,676	132,164
Deferred tax liability
Net deferred loan costs	0	193
Right-of-use asset	5,413	4,548
Intangible assets	451	453
Limited partnership investments	305	1,830
Total deferred tax liability	6,169	7,024
Net deferred tax asset	$ 99,507	$ 125,140