Note 6 - Loans Receivable and Allowances for Loan Losses - Impaired Loans Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
With no related allowance recorded - Average recorded investment	$ 16,164	$ 15,016
With no related allowance recorded - Interest income recognized	94	79
With related allowance recorded - Average recorded investment	12,365	6,661
With related allowance recorded - Interest income recognized	32	35
Average recorded investment	28,529	21,677
Interest income recognized	126	114
Average recorded investment	28,529	21,677
Interest income recognized	126	114
Commercial Real Estate Portfolio Segment [Member]
With no related allowance recorded - Average recorded investment	12,290	11,589
With no related allowance recorded - Interest income recognized	70	65
With related allowance recorded - Average recorded investment	6,759	508
With related allowance recorded - Interest income recognized	5	8
Average recorded investment	19,049	12,097
Interest income recognized	75	73
Average recorded investment	19,049	12,097
Interest income recognized	75	73
Construction and Land Development Portfolio Segment [Member]
With no related allowance recorded - Average recorded investment		117
With no related allowance recorded - Interest income recognized
With related allowance recorded - Average recorded investment
With related allowance recorded - Interest income recognized
Average recorded investment		117
Interest income recognized
Average recorded investment		117
Interest income recognized
Commercial Portfolio Segment [Member]
With no related allowance recorded - Average recorded investment	1,931	1,998
With no related allowance recorded - Interest income recognized	8	10
With related allowance recorded - Average recorded investment	3,303	3,110
With related allowance recorded - Interest income recognized	17	19
Average recorded investment	5,234	5,108
Interest income recognized	25	29
Average recorded investment	5,234	5,108
Interest income recognized	25	29
Owner Occupied Real Estate [Member]
With no related allowance recorded - Average recorded investment	1,126	483
With no related allowance recorded - Interest income recognized	12	1
With related allowance recorded - Average recorded investment	1,774	2,830
With related allowance recorded - Interest income recognized	6	6
Average recorded investment	2,900	3,313
Interest income recognized	18	7
Average recorded investment	2,900	3,313
Interest income recognized	18	7
Consumer Portfolio Segment [Member]
With no related allowance recorded - Average recorded investment	752	829
With no related allowance recorded - Interest income recognized	3	3
With related allowance recorded - Average recorded investment	529	213
With related allowance recorded - Interest income recognized	4	2
Average recorded investment	1,281	1,042
Interest income recognized	7	5
Average recorded investment	1,281	1,042
Interest income recognized	7	5
Residential Portfolio Segment [Member]
With no related allowance recorded - Average recorded investment	65
With no related allowance recorded - Interest income recognized	1
With related allowance recorded - Average recorded investment
With related allowance recorded - Interest income recognized
Average recorded investment	65
Interest income recognized	1
Average recorded investment	65
Interest income recognized	$ 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 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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