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Note 5 - Loans and Related Allowance for Loan and Lease Losses - Impaired Loans by Class (Details) - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Recorded investment, with no related allowance | $ 7,344 | $ 3,380
Unpaid principal balance, with no related allowance | 8,199 | 4,061
Recorded investment, with related allowance | 5,726 | 10,695
Unpaid principal balance, with related allowance | 5,787 | 11,406
Related allowance | 660 | 1,354
Recorded investment | 13,070 | 14,075
Unpaid principal balance | 13,986 | 15,467
Commercial Loans [Member] |  |
Recorded investment, with related allowance | 4,942 |
Unpaid principal balance, with related allowance | 4,952 |
Related allowance | 627 |
Commercial And Industrial [Member] |  |
Recorded investment, with no related allowance | 747 | 207
Unpaid principal balance, with no related allowance | 1,524 | 413
Recorded investment, with related allowance | 135 | 2,363
Unpaid principal balance, with related allowance | 135 | 3,013
Related allowance | 3 | 667
Recorded investment | 882 | 2,570
Unpaid principal balance | 1,659 | 3,426
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] |  |
Recorded investment, with no related allowance | 979 | 1,306
Unpaid principal balance, with no related allowance | 1,057 | 1,462
Recorded investment, with related allowance |  | 664
Unpaid principal balance, with related allowance |  | 715
Related allowance | 30 | 43
Recorded investment | 1,628 | 1,970
Unpaid principal balance | 1,757 | 2,177
Real Estate Mortgage Portfolio Segment [Member] | Commercial Loans [Member] |  |
Recorded investment, with no related allowance | 5,617 | 1,867
Unpaid principal balance, with no related allowance | 5,617 | 2,186
Recorded investment, with related allowance |  | 7,666
Unpaid principal balance, with related allowance |  | 7,676
Related allowance | 627 | 643
Recorded investment | 10,559 | 9,533
Unpaid principal balance | 10,569 | 9,862
Consumer Portfolio Segment [Member] |  |
Recorded investment, with no related allowance | 1 |
Unpaid principal balance, with no related allowance | 1 |
Recorded investment, with related allowance |  | 2
Unpaid principal balance, with related allowance |  | 2
Related allowance |  | 1
Recorded investment | 1 | 2
Unpaid principal balance | 1 | $ 2
Real Estate Construction Porfolio Segment [Member] | Residential Loan [Member] |  |
Recorded investment, with related allowance | 649 |
Unpaid principal balance, with related allowance | 700 |
Related allowance | $ 30 |

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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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 14A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524 + Details
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