Note 4 - Loans - Allowance for Credit Losses and Recorded Investment in Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Balance	$ 11,925	$ 11,544
Charge-offs	(390)	(447)
Recoveries	760	344
Provision		200
Balance	12,295	11,641
Individually evaluated for impairment			$ 1,089	$ 1,169
Collectively evaluated for impairment			11,206	10,756
Total	11,925	11,544	12,295	11,925
Individually evaluated for impairment			11,462	13,147
Collectively evaluated for impairment			888,958	866,688
Total gross loans			900,420	879,835
Commercial Portfolio Segment [Member]
Balance	2,397	2,849
Charge-offs		(51)
Recoveries	453	199
Provision	(552)	(348)
Balance	2,298	2,649
Individually evaluated for impairment			614	690
Collectively evaluated for impairment			1,684	1,707
Total	2,397	2,849	2,298	2,397
Individually evaluated for impairment			2,625	3,154
Collectively evaluated for impairment			135,245	139,251
Total gross loans			137,870	142,405
Commercial Real Estate Portfolio Segment [Member]
Balance	6,514	5,578
Charge-offs
Recoveries		27
Provision	384	358
Balance	6,898	5,963
Individually evaluated for impairment			121	77
Collectively evaluated for impairment			6,777	6,437
Total	6,514	5,578	6,898	6,514
Individually evaluated for impairment			800	1,403
Collectively evaluated for impairment			612,401	584,190
Total gross loans			613,201	585,593
Residential Portfolio Segment [Member]
Balance	1,169	1,716
Charge-offs	(114)	(169)
Recoveries	246	75
Provision	(152)	(132)
Balance	1,149	1,490
Individually evaluated for impairment			343	391
Collectively evaluated for impairment			806	778
Total	1,169	1,716	1,149	1,169
Individually evaluated for impairment			8,002	8,554
Collectively evaluated for impairment			93,190	93,358
Total gross loans			101,192	101,912
Consumer Portfolio Segment [Member]
Balance	1,435	955
Charge-offs	(276)	(227)
Recoveries	61	43
Provision	253	303
Balance	1,473	1,074
Individually evaluated for impairment			11	11
Collectively evaluated for impairment			1,462	1,424
Total	1,435	955	1,473	1,435
Individually evaluated for impairment			35	36
Collectively evaluated for impairment			48,122	49,889
Total gross loans			48,157	49,925
Unallocated Financing Receivables [Member]
Balance	410	446
Charge-offs
Recoveries
Provision	67	19
Balance	477	465
Individually evaluated for impairment
Collectively evaluated for impairment			477	410
Total	$ 410	$ 446	477	410
Individually evaluated for impairment
Collectively evaluated for impairment
Total gross loans

Financing receivable allowance for credit losses, provision.

No definition available.

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 11B
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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- Definition

Amount of direct write-downs of financing receivables charged against the allowance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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-Publisher FASB
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-SubTopic 10
-Section 45
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