Note 5 - Allowances for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
With no related allowance - Recorded investment	$ 15,270	$ 15,740
With no related allowance - Unpaid principal balance	19,666	17,298
With related allowance - Recorded investment	9,446	12,430
With related allowance - Unpaid principal balance	9,502	15,135
Related allowance	2,790	3,468
Recorded investment	24,716	28,170
Unpaid principal balance	29,168	32,433
With no related allowance recorded - Average recorded investment	14,570	15,445	$ 17,612
With no related allowance recorded - Interest income recognized	483	333	381
With related allowance recorded - Average recorded investment	10,817	10,250	11,923
With related allowance recorded - Interest income recognized	124	169	135
Average recorded investment	25,387	25,695	29,535
Interest income recognized	607	502	516
Commercial Real Estate Portfolio Segment [Member]
With no related allowance - Recorded investment	9,264	12,347
With no related allowance - Unpaid principal balance	9,268	12,348
With related allowance - Recorded investment	6,151	6,898
With related allowance - Unpaid principal balance	6,165	6,912
Related allowance	1,964	1,277
Recorded investment	15,415	19,245
Unpaid principal balance	15,433	19,260
With no related allowance recorded - Average recorded investment	9,579	12,033	12,796
With no related allowance recorded - Interest income recognized	366	264	282
With related allowance recorded - Average recorded investment	6,490	4,455	5,544
With related allowance recorded - Interest income recognized	14	52	13
Average recorded investment	16,069	16,488	18,340
Interest income recognized	380	316	295
Construction and Land Development Portfolio Segment [Member]
With no related allowance - Recorded investment
With no related allowance - Unpaid principal balance
With related allowance - Recorded investment
With related allowance - Unpaid principal balance
Related allowance
Recorded investment
Unpaid principal balance
With no related allowance recorded - Average recorded investment		58	206
With no related allowance recorded - Interest income recognized			2
With related allowance recorded - Average recorded investment		12	90
With related allowance recorded - Interest income recognized
Average recorded investment		70	296
Interest income recognized			2
Commercial Portfolio Segment [Member]
With no related allowance - Recorded investment	2,756	1,955
With no related allowance - Unpaid principal balance	6,674	3,111
With related allowance - Recorded investment	1,745	3,225
With related allowance - Unpaid principal balance	1,752	5,892
Related allowance	374	1,624
Recorded investment	4,501	5,180
Unpaid principal balance	8,426	9,003
With no related allowance recorded - Average recorded investment	2,270	1,828	3,225
With no related allowance recorded - Interest income recognized	37	42	78
With related allowance recorded - Average recorded investment	2,517	3,357	2,587
With related allowance recorded - Interest income recognized	68	74	28
Average recorded investment	4,787	5,185	5,812
Interest income recognized	105	116	106
Owner Occupied Real Estate [Member]
With no related allowance - Recorded investment	2,595	621
With no related allowance - Unpaid principal balance	2,743	733
With related allowance - Recorded investment	1,203	1,704
With related allowance - Unpaid principal balance	1,206	1,704
Related allowance	235	274
Recorded investment	3,798	2,325
Unpaid principal balance	3,949	2,437
With no related allowance recorded - Average recorded investment	1,894	642	700
With no related allowance recorded - Interest income recognized	58	10	6
With related allowance recorded - Average recorded investment	1,390	2,104	3,643
With related allowance recorded - Interest income recognized	32	31	92
Average recorded investment	3,284	2,746	4,343
Interest income recognized	90	41	98
Consumer Portfolio Segment [Member]
With no related allowance - Recorded investment	655	687
With no related allowance - Unpaid principal balance	981	976
With related allowance - Recorded investment	347	603
With related allowance - Unpaid principal balance	379	627
Related allowance	217	293
Recorded investment	1,002	1,290
Unpaid principal balance	1,360	1,603
With no related allowance recorded - Average recorded investment	801	858	685
With no related allowance recorded - Interest income recognized	21	16	13
With related allowance recorded - Average recorded investment	420	322	59
With related allowance recorded - Interest income recognized	10	12	2
Average recorded investment	1,221	1,180	744
Interest income recognized	31	28	15
Residential Portfolio Segment [Member]
With no related allowance - Recorded investment		130
With no related allowance - Unpaid principal balance		130
With related allowance - Recorded investment
With related allowance - Unpaid principal balance
Related allowance
Recorded investment		130
Unpaid principal balance		130
With no related allowance recorded - Average recorded investment	26	26
With no related allowance recorded - Interest income recognized	1	1
With related allowance recorded - Average recorded investment
With related allowance recorded - Interest income recognized
Average recorded investment	26	26
Interest income recognized	$ 1	$ 1

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 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5278-111524

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