Note 10 - Income Taxes - Components of Net Deferred Tax Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax asset
Allowance for credit losses	$ 6,852	$ 6,789
State franchise taxes	2,518	2,262
Deferred compensation	4,524	4,789
Purchased assets and assumed liabilities	475	552
Post-retirement benefits	445	480
Employee benefit accruals	2,792	2,353
VISA Class B shares	348	284
Limited partnership investments	0	1,066
Impaired capital assets	2,673	2,429
Accrued liabilities	748	416
Premises and equipment	1,001	585
Lease liability	5,263	5,513
Other	103	800
Sub total deferred tax asset	27,742	28,318
Tax valuation	(1,776)	0
Total deferred tax asset	25,966	28,318
Deferred tax liability
Net deferred loan fees	196	106
Securities available for sale	20,845	48,021
Right-of-use asset	5,263	5,513
Intangible assets	459	456
Limited partnership investment	1,704	0
Total deferred tax liability	28,467	54,096
Net deferred tax liability	$ (2,501)	$ (25,778)