Note 5 - Credit Quality - Average Annual Recorded Investment and Interest Income Recognized on Impaired Loans Excluding Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Impaired loans with no related allowance, interest income recognized	$ 1,436	$ 1,077	$ 976
Impaired loans with no related allowance, average recorded investment	38,230	29,693	28,495
Impaired loans with a related allowance, interest income recognized	46	94	172
Impaired loans with a related allowance, average recorded investment	3,427	2,713	6,860
Total impaired loans, average recorded investment	1,482	1,171	1,148
Total impaired loans, average recorded investment	41,657	32,406	35,355
Commercial Portfolio Segment [Member] \| Construction, Development and Other Land [Member]
Impaired loans with no related allowance, interest income recognized	25	22	26
Impaired loans with no related allowance, average recorded investment	935	704	921
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Impaired loans with no related allowance, interest income recognized	155	34	19
Impaired loans with no related allowance, average recorded investment	2,749	363	383
Commercial Portfolio Segment [Member] \| Multi-family Residential [Member]
Impaired loans with no related allowance, interest income recognized	19	24	47
Impaired loans with no related allowance, average recorded investment	808	1,356	910
Impaired loans with a related allowance, interest income recognized	0	0	2
Impaired loans with a related allowance, average recorded investment	707	0	270
Commercial Portfolio Segment [Member] \| Single Family Non-owner Occupied [Member]
Impaired loans with no related allowance, interest income recognized	189	123	123
Impaired loans with no related allowance, average recorded investment	4,890	2,979	2,652
Impaired loans with a related allowance, interest income recognized	0	0	7
Impaired loans with a related allowance, average recorded investment	0	0	110
Commercial Portfolio Segment [Member] \| Non-farm, Non-residential [Member]
Impaired loans with no related allowance, interest income recognized	295	123	133
Impaired loans with no related allowance, average recorded investment	7,450	4,683	4,828
Impaired loans with a related allowance, interest income recognized	17	48	2
Impaired loans with a related allowance, average recorded investment	1,524	766	809
Commercial Portfolio Segment [Member] \| Agricultural [Member]
Impaired loans with no related allowance, interest income recognized	9	9	0
Impaired loans with no related allowance, average recorded investment	241	121	164
Commercial Portfolio Segment [Member] \| Farmland [Member]
Impaired loans with no related allowance, interest income recognized	63	55	64
Impaired loans with no related allowance, average recorded investment	1,569	1,469	1,172
Impaired loans with a related allowance, interest income recognized	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	307
Consumer Real Estate Portfolio Segment [Member] \| Home Equity Lines [Member]
Impaired loans with no related allowance, interest income recognized	51	46	44
Impaired loans with no related allowance, average recorded investment	1,594	1,439	1,637
Impaired loans with a related allowance, interest income recognized	0	0	3
Impaired loans with a related allowance, average recorded investment	0	0	68
Consumer Real Estate Portfolio Segment [Member] \| Single Family Owner Occupied [Member]
Impaired loans with no related allowance, interest income recognized	578	599	503
Impaired loans with no related allowance, average recorded investment	17,044	16,058	15,423
Impaired loans with a related allowance, interest income recognized	29	46	158
Impaired loans with a related allowance, average recorded investment	1,196	1,947	5,296
Consumer Real Estate Portfolio Segment [Member] \| Owner Occupied Construction [Member]
Impaired loans with no related allowance, interest income recognized	10	29	8
Impaired loans with no related allowance, average recorded investment	407	308	244
Consumer and Other Portfolio Segment [Member] \| Consumer Loans [Member]
Impaired loans with no related allowance, interest income recognized	42	13	9
Impaired loans with no related allowance, average recorded investment	$ 543	$ 213	$ 161

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

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