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Note 5 - Loans and Related Allowance for Loan and Lease Losses - Additional Information on Impaired Loans (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Average recorded investment | $ 14,297 | $ 14,589
Interest income recognized | 358 | 567
Commercial Real Estate Portfolio Segment [Member] | Owner Occupied Loan [Member] |  |
Average recorded investment | 2,851 | 3,808
Interest income recognized | 72 | 176
Commercial Real Estate Portfolio Segment [Member] | Non-owner occupied Loan [Member] |  |
Average recorded investment | 8,815 | 6,558
Interest income recognized | 184 | 199
Residential Portfolio Segment [Member] |  |
Average recorded investment | 1,247 | 1,626
Interest income recognized | 52 | 49
Commercial And Industrial [Member] |  |
Average recorded investment | 1,076 | 1,770
Interest income recognized | 42 | 141
Home Equity Lines of Credit [Member] |  |
Average recorded investment | 308 | 177
Interest income recognized | 8 | 2
Construction and Other [Member] |  |
Average recorded investment | 0 | 648
Interest income recognized | 0 | 0
Consumer Portfolio Segment [Member] |  |
Average recorded investment | 0 | 2
Interest income recognized | $ 0 | $ 0

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