Note 4 - 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	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Average recorded investment	$ 25,929	$ 30,732	$ 23,669	$ 28,853
Impaired loans with no related allowance, interest income recognized	161	298	315	449
Impaired loans with a related allowance, average recorded investment	7,367	10,534	8,198	10,778
Impaired loans with a related allowance, interest income recognized	81	117	149	250
Total impaired loans, average recorded investment	33,296	41,266	31,867	39,631
Interest income recognized	242	415	464	699
Commercial Portfolio Segment [Member] \| Construction, Development and Other Land [Member]
Average recorded investment	10	571	11	370
Impaired loans with no related allowance, interest income recognized
Impaired loans with a related allowance, average recorded investment			214
Impaired loans with a related allowance, interest income recognized
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Average recorded investment	321	1,039	325	593
Impaired loans with no related allowance, interest income recognized	1	4	3	4
Impaired loans with a related allowance, average recorded investment	2,352		1,332
Impaired loans with a related allowance, interest income recognized	38		53
Commercial Portfolio Segment [Member] \| Multi-family Residential [Member]
Average recorded investment	557	299	457	184
Impaired loans with no related allowance, interest income recognized	3		3
Commercial Portfolio Segment [Member] \| Single Family Non-owner Occupied [Member]
Average recorded investment	3,308	3,588	3,317	2,803
Impaired loans with no related allowance, interest income recognized	34		77	16
Impaired loans with a related allowance, average recorded investment	344	677	344	517
Impaired loans with a related allowance, interest income recognized	5	6	13	13
Commercial Portfolio Segment [Member] \| Non-farm, Non-residential [Member]
Average recorded investment	3,330	9,893	3,027	10,814
Impaired loans with no related allowance, interest income recognized	21	171	25	242
Impaired loans with a related allowance, average recorded investment	867	5,307	1,011	5,333
Impaired loans with a related allowance, interest income recognized	5	82	15	170
Commercial Portfolio Segment [Member] \| Agricultural [Member]
Average recorded investment	128		127
Impaired loans with no related allowance, interest income recognized
Commercial Portfolio Segment [Member] \| Farmland [Member]
Average recorded investment	1,003	208	1,005	176
Impaired loans with no related allowance, interest income recognized		4		4
Impaired loans with a related allowance, average recorded investment	411		205
Impaired loans with a related allowance, interest income recognized
Consumer Real Estate Portfolio Segment [Member] \| Home Equity Lines [Member]
Average recorded investment	1,052	1,450	1,047	1,398
Impaired loans with no related allowance, interest income recognized	5	8	20	15
Impaired loans with a related allowance, average recorded investment			209
Impaired loans with a related allowance, interest income recognized
Consumer Real Estate Portfolio Segment [Member] \| Single Family Owner Occupied [Member]
Average recorded investment	15,943	13,063	14,074	12,067
Impaired loans with no related allowance, interest income recognized	93	109	180	163
Impaired loans with a related allowance, average recorded investment	3,393	4,550	4,883	4,755
Impaired loans with a related allowance, interest income recognized	33	29	68	67
Consumer Real Estate Portfolio Segment [Member] \| Owner Occupied Construction [Member]
Average recorded investment	234	583	233	412
Impaired loans with no related allowance, interest income recognized	2	2	5	5
Impaired loans with a related allowance, average recorded investment				173
Impaired loans with a related allowance, interest income recognized
Consumer and Other Portfolio Segment [Member] \| Consumer Loan [Member]
Average recorded investment	43	38	46	36
Impaired loans with no related allowance, interest income recognized	$ 2		$ 2

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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

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