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Loans and ALLL (Summary of information pertaining to TDRs) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) loan | Dec. 31, 2018 USD ($) loan
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 11 | 45
Pre-Modification Recorded Investment | $ 4,491 | $ 8,379
Post-Modification Recorded Investment | $ 4,491 | $ 8,356
Commercial other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 3 | 4
Pre-Modification Recorded Investment | $ 1,188 | $ 1,360
Post-Modification Recorded Investment | $ 1,188 | $ 1,360
Agricultural other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 7 | 31
Pre-Modification Recorded Investment | $ 3,286 | $ 6,318
Post-Modification Recorded Investment | $ 3,286 | $ 6,295
Residential real estate senior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 10
Pre-Modification Recorded Investment | $ 17 | $ 701
Post-Modification Recorded Investment | $ 17 | $ 701
Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 9 | 23
Pre-Modification Recorded Investment | $ 3,302 | $ 5,377
Below Market Interest Rate and Extension of Amortization Period [Member] | Commercial other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 3 | 3
Pre-Modification Recorded Investment | $ 1,188 | $ 1,186
Below Market Interest Rate and Extension of Amortization Period [Member] | Agricultural other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 5 | 13
Pre-Modification Recorded Investment | $ 2,097 | $ 3,693
Below Market Interest Rate and Extension of Amortization Period [Member] | Residential real estate senior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 7
Pre-Modification Recorded Investment | $ 17 | $ 498
Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 22
Pre-Modification Recorded Investment | $ 1,189 | $ 3,002
Interest Rate Below Market Reduction [Member] | Commercial other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 174
Interest Rate Below Market Reduction [Member] | Agricultural other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 18
Pre-Modification Recorded Investment | $ 1,189 | $ 2,625
Interest Rate Below Market Reduction [Member] | Residential real estate senior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 3
Pre-Modification Recorded Investment | $ 0 | $ 203

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