Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Restructurings By Class (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Number of contracts	2	4	6	7
Pre-modification outstanding principal balance	$ 338	$ 1,130	$ 3,935	$ 1,380
Post-modification outstanding principal balance	$ 338	$ 1,130	$ 3,935	$ 1,380
Residential Portfolio Segment [Member] \| Investor Owned Residential Real Estate [Member]
Number of contracts	2		2
Pre-modification outstanding principal balance	$ 338		$ 338
Post-modification outstanding principal balance	$ 338		$ 338
Commercial Real Estate Portfolio Segment [Member] \| Commercial Real Estate Other [Member]
Number of contracts			2
Pre-modification outstanding principal balance			$ 2,882
Post-modification outstanding principal balance			$ 2,882
Commercial Real Estate Portfolio Segment [Member] \| Commercial Real Estate, Owner Occupied [Member]
Number of contracts			2	1
Pre-modification outstanding principal balance			$ 715	$ 132
Post-modification outstanding principal balance			$ 715	$ 132
Commercial Non Real Estate Segment [Member]
Number of contracts		2		4
Commercial Non Real Estate Segment [Member] \| Commercial and Industrial [Member]
Number of contracts		2		4
Pre-modification outstanding principal balance		$ 1,116		$ 1,234
Post-modification outstanding principal balance		$ 1,116		$ 1,234
Consumer Non Real Estate Portfolio Segment [Member] \| Automobile Loan [Member]
Number of contracts		2		2
Pre-modification outstanding principal balance		$ 14		$ 14
Post-modification outstanding principal balance		$ 14		$ 14

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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