Note 5 - Credit Quality - Average Annual Recorded Investment and Interest Income Recognized on Impaired Loans Excluding Purchased Credit Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Impaired loans with no related allowance, interest income recognized	$ 353	$ 303	$ 1,051	$ 784
Impaired loans with no related allowance, average recorded investment	38,716	29,811	37,879	29,844
Impaired loans with a related allowance, interest income recognized	11	10	49	63
Impaired loans with a related allowance, average recorded investment	4,156	2,507	4,093	2,779
Impaired loans with a related allowance, interest income recognized	(11)	(10)	(49)	(63)
Total impaired loans, average recorded investment	364	293	1,100	847
Total impaired loans, average recorded investment	42,872	32,318	41,972	32,623
Commercial Portfolio Segment [Member] \| Construction, Development and Other Land [Member]
Impaired loans with no related allowance, interest income recognized	6	5	21	17
Impaired loans with no related allowance, average recorded investment	882	570	1,021	720
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Impaired loans with no related allowance, interest income recognized	46	2	135	7
Impaired loans with no related allowance, average recorded investment	3,315	66	2,845	277
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Commercial Portfolio Segment [Member] \| Multi-family Residential [Member]
Impaired loans with no related allowance, interest income recognized	9	5	38	21
Impaired loans with no related allowance, average recorded investment	967	1,269	685	1,385
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	944	0	943	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Commercial Portfolio Segment [Member] \| Single Family Non-owner Occupied [Member]
Impaired loans with no related allowance, interest income recognized	54	41	126	97
Impaired loans with no related allowance, average recorded investment	5,090	2,958	4,798	3,063
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Commercial Portfolio Segment [Member] \| Non-farm, Non-residential [Member]
Impaired loans with no related allowance, interest income recognized	79	20	206	84
Impaired loans with no related allowance, average recorded investment	7,786	4,590	7,115	4,832
Impaired loans with a related allowance, interest income recognized	8	20	22	28
Impaired loans with a related allowance, average recorded investment	1,789	1,254	1,670	602
Impaired loans with a related allowance, interest income recognized	(8)	(20)	(22)	(28)
Commercial Portfolio Segment [Member] \| Agricultural [Member]
Impaired loans with no related allowance, interest income recognized	4	9	7	11
Impaired loans with no related allowance, average recorded investment	272	223	247	108
Commercial Portfolio Segment [Member] \| Farmland [Member]
Impaired loans with no related allowance, interest income recognized	12	19	48	45
Impaired loans with no related allowance, average recorded investment	1,526	1,536	1,640	1,474
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Consumer Real Estate Portfolio Segment [Member] \| Home Equity Lines [Member]
Impaired loans with no related allowance, interest income recognized	13	17	29	31
Impaired loans with no related allowance, average recorded investment	1,588	1,463	1,569	1,452
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Consumer Real Estate Portfolio Segment [Member] \| Single Family Owner Occupied [Member]
Impaired loans with no related allowance, interest income recognized	120	176	410	454
Impaired loans with no related allowance, average recorded investment	16,328	16,593	17,044	16,123
Impaired loans with a related allowance, interest income recognized	3	30	27	35
Impaired loans with a related allowance, average recorded investment	1,423	1,253	1,480	2,177
Impaired loans with a related allowance, interest income recognized	(3)	(30)	(27)	(35)
Consumer Real Estate Portfolio Segment [Member] \| Owner Occupied Construction [Member]
Impaired loans with no related allowance, interest income recognized	2	3	12	7
Impaired loans with no related allowance, average recorded investment	542	224	470	223
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Impaired loans with a related allowance, average recorded investment	0	0	0	0
Impaired loans with a related allowance, interest income recognized	0	0	0	0
Consumer and Other Portfolio Segment [Member] \| Consumer Loans [Member]
Impaired loans with no related allowance, interest income recognized	8	6	19	10
Impaired loans with no related allowance, average recorded investment	$ 420	$ 319	$ 445	$ 187

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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