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Allowance for Loan Losses and Credit Quality of Loans, Impaired Loans (Details) - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Allowance for Loan Losses and Credit Quality of Loans [Abstract] |  |
Threshold balance for classified loans to be evaluated individually for impairment | $ 800 |
Total [Abstract] |  |
Recorded investment balance (book) | 19,736 | $ 28,874
Unpaid principal balance (legal) | 26,355 | 31,582
Related allowance | 30 | 1,517
Originated Loans [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 19,658 | 21,912
Unpaid principal balance (legal) | 26,272 | 24,321
Originated Loans [Member] | Commercial Loans [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 4,777 | 7,313
Unpaid principal balance (legal) | 7,709 | 7,970
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 78 | 5,757
Unpaid principal balance (legal) | 83 | 5,940
Total [Abstract] |  |
Related allowance | 30 | 826
Originated Loans [Member] | Commercial Loans [Member] | Commercial [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 0 | 1,278
Unpaid principal balance (legal) | 251 | 1,697
Originated Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 2,239 | 3,816
Unpaid principal balance (legal) | 3,996 | 3,841
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 78 | 5,553
Unpaid principal balance (legal) | 83 | 5,736
Total [Abstract] |  |
Related allowance | 30 | 735
Originated Loans [Member] | Commercial Loans [Member] | Agricultural [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 100 | 130
Unpaid principal balance (legal) | 112 | 137
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 0 | 49
Unpaid principal balance (legal) | 0 | 49
Total [Abstract] |  |
Related allowance | 0 | 37
Originated Loans [Member] | Commercial Loans [Member] | Agricultural Real Estate [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 1,491 | 1,434
Unpaid principal balance (legal) | 1,663 | 1,567
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 0 | 155
Unpaid principal balance (legal) | 0 | 155
Total [Abstract] |  |
Related allowance | 0 | 54
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 947 | 655
Unpaid principal balance (legal) | 1,687 | 728
Originated Loans [Member] | Consumer Loans [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 8,307 | 8,488
Unpaid principal balance (legal) | 10,228 | 9,445
Originated Loans [Member] | Consumer Loans [Member] | Indirect [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 36 | 5
Unpaid principal balance (legal) | 47 | 16
Originated Loans [Member] | Consumer Loans [Member] | Home Equity [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 8,153 | 8,483
Unpaid principal balance (legal) | 10,063 | 9,429
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 118 | 0
Unpaid principal balance (legal) | 118 | 0
Originated Loans [Member] | Residential Real Estate Mortgages [Member] |  |
With no related allowance recorded [Abstract] |  |
Recorded investment balance (book) | 6,574 | 6,111
Unpaid principal balance (legal) | 8,335 | 6,906
Acquired Loans [Member] | Commercial Loans [Member] |  |
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 0 | 1,205
Unpaid principal balance (legal) | 0 | 1,321
Total [Abstract] |  |
Related allowance | 0 | 691
Acquired Loans [Member] | Commercial Loans [Member] | Commercial Real Estate [Member] |  |
With an allowance recorded [Abstract] |  |
Recorded investment balance (book) | 0 | 1,205
Unpaid principal balance (legal) | 0 | 1,321
Total [Abstract] |  |
Related allowance | $ 0 | $ 691

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