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Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Impaired Loans, Average Investment and Interest Income (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019
Average recorded investment in impaired loans(1) | [1],[2],[3] | $ 5,677 |  | $ 6,597 | $ 5,359 |
Interest income recognized on impaired loans, after designation as impaired |  | 26 |  | 49 | 171 |
Consumer Real Estate Portfolio Segment [Member] | Equity Lines [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) |  | 100 | [1],[2],[4] |  | 98 |
Interest income recognized on impaired loans, after designation as impaired |  | 2 | [4] |  | 6 |
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] | 22 |  | 710 |  |
Interest income recognized on impaired loans, after designation as impaired | [4] |  |  | 9 |  |
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] |  |  | 142 |  |
Interest income recognized on impaired loans, after designation as impaired | [4] |  |  | 2 |  |
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member] | Financing Receivables 30 to 89 Days Past Due [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2] |  |  |  | 225 |
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2] |  |  |  | 11 |
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] | 487 |  | 570 | 439 |
Interest income recognized on impaired loans, after designation as impaired | [4] | 4 |  | 9 | 17 |
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] | 890 |  | 1,207 | 913 |
Interest income recognized on impaired loans, after designation as impaired | [4] | 6 |  | 5 | 41 |
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] |  |  | 471 | 284 |
Interest income recognized on impaired loans, after designation as impaired | [4] |  |  | 7 | 12 |
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] | 3,257 |  | 2,484 | 2,435 |
Interest income recognized on impaired loans, after designation as impaired | [4] | 8 |  | 11 | 59 |
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2],[4] | 917 |  | 1,002 | 962 |
Interest income recognized on impaired loans, after designation as impaired | [4] | 6 |  | 6 | 25 |
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member] |  |  |  |  |  |
Average recorded investment in impaired loans(1) | [1],[2] | 4 | [4] | 11 | 3 | [4]
Interest income recognized on impaired loans, after designation as impaired |  |  | [4] |  |  | [4]
[1] | Only classes with past due or nonaccrual loans are presented
[2] | Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.
[3] | Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.
[4] | Only classes with impaired loans are shown.

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