Note 6 - Allowance for Loan Losses and Credit Quality Information - Financial Effects of Troubled Debt Restructurings (Details) $ in Thousands	12 Months Ended
Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Number of Contracts	25	27
Pre- modification Outstanding Recorded Investment	$ 2,164	$ 1,256
Post- modification Outstanding Recorded Investment	$ 2,122	$ 1,261
Residential Portfolio Segment [Member]
Number of Contracts	4	4
Pre- modification Outstanding Recorded Investment	$ 251	$ 476
Post- modification Outstanding Recorded Investment	$ 263	$ 478
Commercial Real Estate Portfolio Segment [Member] \| Commercial Real Estate Other [Member]
Number of Contracts	1	1
Pre- modification Outstanding Recorded Investment	$ 1,274	$ 209
Post- modification Outstanding Recorded Investment	$ 1,274	$ 209
Consumer Portfolio Segment [Member]
Number of Contracts	18	21
Pre- modification Outstanding Recorded Investment	$ 382	$ 527
Post- modification Outstanding Recorded Investment	$ 384	$ 530
Commercial Portfolio Segment [Member] \| Commercial Business Other [Member]
Number of Contracts	2	1
Pre- modification Outstanding Recorded Investment	$ 257	$ 44
Post- modification Outstanding Recorded Investment	$ 201	$ 44

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953676-111524

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