Note 4 - Loans - Allowance for Credit Losses and Recorded Investment in Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Dec. 31, 2017
Balance	$ 12,388	$ 11,688	$ 11,925	$ 11,544
Charge-offs	(198)	(245)	(969)	(1,051)
Recoveries	202	249	1,436	699
Provision for loan and lease losses				500
Balance	12,392	11,692	12,392	11,692
Individually evaluated for impairment					$ 1,118	$ 1,169
Collectively evaluated for impairment					11,274	10,756
Total	12,388	11,688	12,392	11,692	12,392	11,925
Individually evaluated for impairment					10,707	13,147
Collectively evaluated for impairment					916,773	866,688
Total gross loans					927,480	879,835
Commercial Portfolio Segment [Member]
Balance	2,442	2,850	2,397	2,849
Charge-offs			(132)	(50)
Recoveries	35	148	838	383
Provision for loan and lease losses	(248)	(354)	(874)	(538)
Balance	2,229	2,644	2,229	2,644
Individually evaluated for impairment					635	690
Collectively evaluated for impairment					1,594	1,707
Total	2,442	2,850	2,229	2,644	2,229	2,397
Individually evaluated for impairment					2,190	3,154
Collectively evaluated for impairment					129,901	139,251
Total gross loans					132,091	142,405
Commercial Real Estate Portfolio Segment [Member]
Balance	7,091	6,072	6,514	5,578
Charge-offs
Recoveries				27
Provision for loan and lease losses	116	232	693	699
Balance	7,207	6,304	7,207	6,304
Individually evaluated for impairment					208	77
Collectively evaluated for impairment					6,999	6,437
Total	7,091	6,072	7,207	6,304	7,207	6,514
Individually evaluated for impairment					797	1,403
Collectively evaluated for impairment					646,553	584,190
Total gross loans					647,350	585,593
Residential Portfolio Segment [Member]
Balance	1,111	1,197	1,169	1,716
Charge-offs		(86)	(164)	(370)
Recoveries	89	13	382	107
Provision for loan and lease losses	12	60	(175)	(269)
Balance	1,212	1,184	1,212	1,184
Individually evaluated for impairment					267	391
Collectively evaluated for impairment					945	778
Total	1,111	1,197	1,212	1,184	1,212	1,169
Individually evaluated for impairment					7,696	8,554
Collectively evaluated for impairment					92,843	93,358
Total gross loans					100,539	101,912
Consumer Portfolio Segment [Member]
Balance	1,317	1,137	1,435	955
Charge-offs	(198)	(159)	(673)	(631)
Recoveries	78	88	216	182
Provision for loan and lease losses	90	134	309	694
Balance	1,287	1,200	1,287	1,200
Individually evaluated for impairment					8	11
Collectively evaluated for impairment					1,279	1,424
Total	1,317	1,137	1,287	1,200	1,287	1,435
Individually evaluated for impairment					24	36
Collectively evaluated for impairment					47,476	49,889
Total gross loans					47,500	49,925
Unallocated Financing Receivables [Member]
Balance	427	432	410	446
Charge-offs
Recoveries
Provision for loan and lease losses	30	(72)	47	(86)
Balance	457	360	457	360
Individually evaluated for impairment
Collectively evaluated for impairment					457	410
Total	$ 427	$ 432	$ 457	$ 360	457	410
Individually evaluated for impairment
Collectively evaluated for impairment
Total gross loans

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

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

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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.

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