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Note 5 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Impaired Loans and Associated Reserves (Details) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Principal balance |  | $ 12,319 | $ 9,820
Total recorded investment | [1] | 11,924 | 9,173
Recorded investment for which there is no related allowance | [1] | 10,444 | 8,269
Recorded investment for which there is a related allowance | [1] | 1,480 | 904
Related allowance |  | 177 | 26
Real Estate Construction Portfolio Segment[Member] | Construction, Other [Member] |  |  |
Principal balance | [2] | 2,882 |
Total recorded investment | [1],[2] | 2,882 |
Recorded investment for which there is no related allowance | [1],[2] | 2,882 |
Recorded investment for which there is a related allowance | [1],[2] | 0 |
Related allowance | [2] | 0 |
Real Estate Construction Portfolio Segment[Member] | Construction, 1-4 Family Residential [Member] |  |  |
Principal balance | [2] |  | 280
Total recorded investment | [1],[2] |  | 270
Recorded investment for which there is no related allowance | [1],[2] |  | 270
Recorded investment for which there is a related allowance | [1],[2] |  | 0
Related allowance | [2] |  | 0
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member] |  |  |
Principal balance | [2] | 807 | 648
Total recorded investment | [1],[2] | 768 | 609
Recorded investment for which there is no related allowance | [1],[2] | 590 | 267
Recorded investment for which there is a related allowance | [1],[2] | 178 | 342
Related allowance | [2] | 10 | 14
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member] |  |  |
Principal balance | [2] | 174 | 195
Total recorded investment | [1],[2] | 174 | 195
Recorded investment for which there is no related allowance | [1],[2] | 0 | 0
Recorded investment for which there is a related allowance | [1],[2] | 174 | 195
Related allowance | [2] | 6 | 7
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member] |  |  |
Principal balance | [2] | 347 | 73
Total recorded investment | [1],[2] | 325 | 73
Recorded investment for which there is no related allowance | [1],[2] | 325 |
Recorded investment for which there is a related allowance | [1],[2] | 0 | 73
Related allowance | [2] | 0 | 4
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member] |  |  |
Principal balance | [2] | 303 | 1,364
Total recorded investment | [1],[2] | 303 | 1,091
Recorded investment for which there is no related allowance | [1],[2] | 303 | 1,091
Recorded investment for which there is a related allowance | [1],[2] |  |
Related allowance | [2] | 0 | 0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member] |  |  |
Principal balance | [2] | 3,619 | 4,005
Total recorded investment | [1],[2] | 3,611 | 3,957
Recorded investment for which there is no related allowance | [1],[2] | 3,611 | 3,663
Recorded investment for which there is a related allowance | [1],[2] | 0 | 294
Related allowance | [2] | 0 | 1
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member] |  |  |
Principal balance | [2] | 2,921 | 2,997
Total recorded investment | [1],[2] | 2,602 | 2,734
Recorded investment for which there is no related allowance | [1],[2] | 2,602 | 2,734
Recorded investment for which there is a related allowance | [1],[2] | 0 | 0
Related allowance | [2] | 0 | 0
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member] |  |  |
Principal balance | [2] | 1,236 | 255
Total recorded investment | [1],[2] | 1,229 | 241
Recorded investment for which there is no related allowance | [1],[2] | 126 | 241
Recorded investment for which there is a related allowance | [1],[2] | 1,103 |
Related allowance | [2] | 160 |
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member] |  |  |
Principal balance | [2] | 30 | 3
Total recorded investment | [1],[2] | 30 | 3
Recorded investment for which there is no related allowance | [1],[2] | 5 | 3
Recorded investment for which there is a related allowance | [1],[2] | 25 |
Related allowance | [2] | $ 1 |
[1] | Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.
[2] | Only classes with impaired loans are shown.

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- Definition Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524 + Details
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