Note 9 - Allowance for Loan Losses and Credit Quality Information - Financial Effects of Troubled Debt Restructurings (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)
Number of Contracts	5	5	13	10
Pre- modification Outstanding Recorded Investment	$ 460	$ 314	$ 2,031	$ 640
Post- modification Outstanding Recorded Investment	$ 460	$ 315	$ 2,034	$ 874
Residential Portfolio Segment [Member]
Number of Contracts	0	0	1	3
Pre- modification Outstanding Recorded Investment	$ 0	$ 0	$ 55	$ 282
Post- modification Outstanding Recorded Investment	$ 0	$ 0	$ 58	$ 514
Consumer Portfolio Segment [Member]
Number of Contracts	4	5	8	7
Pre- modification Outstanding Recorded Investment	$ 216	$ 314	$ 334	$ 358
Post- modification Outstanding Recorded Investment	$ 216	$ 315	$ 334	$ 360
Commercial Real Estate Portfolio Segment [Member] \| Real Estate Loan [Member]
Number of Contracts	0		1
Pre- modification Outstanding Recorded Investment	$ 0		$ 54
Post- modification Outstanding Recorded Investment	$ 0		$ 54
Commercial Real Estate Portfolio Segment [Member] \| Commercial Real Estate Other [Member]
Number of Contracts	1		2
Pre- modification Outstanding Recorded Investment	$ 244		$ 1,518
Post- modification Outstanding Recorded Investment	$ 244		$ 1,518
Commercial Portfolio Segment [Member]
Number of Contracts	0		1
Pre- modification Outstanding Recorded Investment	$ 0		$ 70
Post- modification Outstanding Recorded Investment	$ 0		$ 70

Number of financing receivables that have been modified by troubled debt restructurings.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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