Note 3 - Loans and Allowance for Credit Losses on Loans - Allowance for Loan Losses by Portfolio Segment and Based on Impairment Evaluation Method (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Beginning balance	$ 79,374	$ 73,531	$ 73,531
Provision for credit losses	1,175	2,250
Charge-offs	(262)	(370)	(7,512)
Recoveries	(610)	(262)
Ending balance	80,897	75,673	79,374
Loans, individually evaluated for impairment	23,243		30,842
Allowance for loans, individually evaluated for impairment	2,456		3,833
Real Estate [Member]
Loans, individually evaluated for impairment	19,462		26,318
Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	3,186		4,189
Other Collateral [Member]
Loans, individually evaluated for impairment	595		335
Home Equity Line of Credit [Member]
Beginning balance	1,660	1,613	1,613
Provision for credit losses	4	17
Charge-offs	0	(12)
Recoveries	(2)	0
Ending balance	1,666	1,618	1,660
Loans, individually evaluated for impairment	515		467
Allowance for loans, individually evaluated for impairment	0		0
Home Equity Line of Credit [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	515		467
Home Equity Line of Credit [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Home Equity Line of Credit [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member]
Beginning balance	33,800	33,468	33,468
Provision for credit losses	(767)	(389)
Charge-offs	0	0
Recoveries	(20)	(19)
Ending balance	33,053	33,098	33,800
Loans, individually evaluated for impairment	12,260		18,005
Allowance for loans, individually evaluated for impairment	1,511		2,416
Commercial Real Estate Portfolio Segment [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	12,260		18,005
Commercial Real Estate Portfolio Segment [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Beginning balance	22,133	22,641	22,641
Provision for credit losses	(326)	(991)
Charge-offs	0	0	0
Recoveries	(16)	(19)
Ending balance	21,823	21,669	22,133
Loans, individually evaluated for impairment	10,518		15,419
Allowance for loans, individually evaluated for impairment	902		1,604
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	10,518		15,419
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Beginning balance	11,667	10,827	10,827
Provision for credit losses	(441)	602
Charge-offs	0	0	0
Recoveries	(4)	0
Ending balance	11,230	11,429	11,667
Loans, individually evaluated for impairment	1,742		2,586
Allowance for loans, individually evaluated for impairment	609		812
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	1,742		2,586
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Commercial and Industrial Portfolio Segment [Member]
Loans, individually evaluated for impairment	6,006		7,272
Allowance for loans, individually evaluated for impairment	620		1,085
Commercial and Industrial Portfolio Segment [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	2,572		3,083
Commercial and Industrial Portfolio Segment [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	3,186		4,189
Commercial and Industrial Portfolio Segment [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	248		0
Commercial and Industrial Portfolio Segment [Member] | Term [Member]
Beginning balance	14,359	12,991	12,991
Provision for credit losses	(673)	991
Charge-offs	(23)	(71)	(2,298)
Recoveries	(253)	(87)
Ending balance	13,916	13,998	14,359
Loans, individually evaluated for impairment	3,693		4,390
Allowance for loans, individually evaluated for impairment	0		377
Commercial and Industrial Portfolio Segment [Member] | Term [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	360		302
Commercial and Industrial Portfolio Segment [Member] | Term [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	3,085		4,088
Commercial and Industrial Portfolio Segment [Member] | Term [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	248		0
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member]
Beginning balance	6,495	6,389	6,389
Provision for credit losses	(441)	(364)
Charge-offs	0	0
Recoveries	(204)	0
Ending balance	6,258	6,025	6,495
Loans, individually evaluated for impairment	2,313		2,882
Allowance for loans, individually evaluated for impairment	620		708
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	2,212		2,781
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	101		101
Commercial and Industrial Portfolio Segment [Member] | Lines of Credit [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Total Commercial and Industrial Portfolio Segment [Member]
Beginning balance	20,854	19,380	19,380
Provision for credit losses	(1,114)	627
Charge-offs	(23)	(71)
Recoveries	(457)	(87)
Ending balance	20,174	20,023	20,854
Residential Real Estate Portfolio Segment [Member]
Beginning balance	13,598	10,314	10,314
Provision for credit losses	2,958	2,024
Charge-offs	(14)	0
Recoveries	(15)	(11)
Ending balance	16,557	12,349	13,598
Loans, individually evaluated for impairment	4,115		4,763
Allowance for loans, individually evaluated for impairment	314		314
Residential Real Estate Portfolio Segment [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	4,115		4,763
Residential Real Estate Portfolio Segment [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Residential Real Estate Portfolio Segment [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member]
Beginning balance	4,282	3,597	3,597
Provision for credit losses	449	546
Charge-offs	0	0	0
Recoveries	0	(1)
Ending balance	4,731	4,144	4,282
Loans, individually evaluated for impairment	579		558
Allowance for loans, individually evaluated for impairment	116		116
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	579		558
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Residential Real Estate Portfolio Segment [Member] | Non-owner Occupied [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member]
Beginning balance	9,316	6,717	6,717
Provision for credit losses	2,509	1,478
Charge-offs	(14)	0	(43)
Recoveries	(15)	(10)
Ending balance	11,826	8,205	9,316
Loans, individually evaluated for impairment	3,536		4,205
Allowance for loans, individually evaluated for impairment	198		198
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	3,536		4,205
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Residential Real Estate Portfolio Segment [Member] | Owner Occupied [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Construction and Development [Member]
Beginning balance	7,593	7,186	7,186
Provision for credit losses	(134)	(451)
Charge-offs	0	0	0
Recoveries	0	0
Ending balance	7,459	6,735	7,593
Loans, individually evaluated for impairment	0		0
Allowance for loans, individually evaluated for impairment	0		0
Construction and Development [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	0		0
Construction and Development [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Construction and Development [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Consumer Portfolio Segment [Member]
Beginning balance	1,407	1,158	1,158
Provision for credit losses	192	88
Charge-offs	(210)	(199)	(865)
Recoveries	(111)	(139)
Ending balance	1,500	1,186	1,407
Loans, individually evaluated for impairment	347		335
Allowance for loans, individually evaluated for impairment	11		18
Consumer Portfolio Segment [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	0		0
Consumer Portfolio Segment [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Consumer Portfolio Segment [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	347		335
Finance Leases Portfolio Segment [Member]
Beginning balance	220	201	201
Provision for credit losses	12	(2)
Charge-offs	0	0	0
Recoveries	0	0
Ending balance	232	199	220
Loans, individually evaluated for impairment	0		0
Allowance for loans, individually evaluated for impairment	0		0
Finance Leases Portfolio Segment [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	0		0
Finance Leases Portfolio Segment [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Finance Leases Portfolio Segment [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	0		0
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member]
Beginning balance	242	211	211
Provision for credit losses	24	336
Charge-offs	(15)	(88)	(661)
Recoveries	(5)	(6)
Ending balance	256	$ 465	242
Loans, individually evaluated for impairment	0		0
Allowance for loans, individually evaluated for impairment	0		0
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Real Estate [Member]
Loans, individually evaluated for impairment	0		0
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Accounts Receivable and Equipment [Member]
Loans, individually evaluated for impairment	0		0
Commercial Portfolio Segment [Member] | Credit Card Receivable [Member] | Other Collateral [Member]
Loans, individually evaluated for impairment	$ 0		$ 0