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Loans and ALLL (Summary of information pertaining to TDRs) (Details) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2019 USD ($) loan | Mar. 31, 2018 USD ($) loan
Financing Receivable, Modifications [Line Items] |  |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | $ 10,549 | $ 14,870
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | $ 123 | $ 193
Number of Loans | loan | 3 | 7
Pre-Modification Recorded Investment | $ 670 | $ 2,483
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 670 | $ 2,483
Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 2
Pre-Modification Recorded Investment | $ 0 | $ 272
Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 3 | 5
Pre-Modification Recorded Investment | $ 670 | $ 2,211
Commercial other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 12 | 1,547
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | $ 0 | $ 24
Number of Loans | loan | 1 | 3
Pre-Modification Recorded Investment | $ 147 | $ 1,255
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 147 | $ 1,255
Commercial other [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 174
Commercial other [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 2
Pre-Modification Recorded Investment | $ 147 | $ 1,081
Agricultural other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 44 | 0
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | $ 0 | $ 0
Number of Loans | loan | 2 | 2
Pre-Modification Recorded Investment | $ 523 | $ 1,061
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 523 | $ 1,061
Agricultural other [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 98
Agricultural other [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 1
Pre-Modification Recorded Investment | $ 523 | $ 963
Residential real estate senior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 6,682 | 7,824
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | $ 68 | $ 74
Number of Loans | loan | 0 | 2
Pre-Modification Recorded Investment | $ 0 | $ 167
Financing Receivable, Modifications, Post-Modification Recorded Investment | $ 0 | $ 167
Residential real estate senior liens [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 0
Pre-Modification Recorded Investment | $ 0 | $ 0
Residential real estate senior liens [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 2
Pre-Modification Recorded Investment | $ 0 | $ 167
Residential real estate junior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment | 12 | 40
Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method | $ 0 | $ 0

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