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Loans and ALLL (Summary of information pertaining to TDRs) (Details) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2018 USD ($) loan | Mar. 31, 2017 USD ($) loan
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 7 | 3
Pre-Modification Recorded Investment | $ 2,483 | $ 235
Post-Modification Recorded Investment | $ 2,483 | $ 235
Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 1
Pre-Modification Recorded Investment | $ 272 | $ 8
Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 5 | 2
Pre-Modification Recorded Investment | $ 2,211 | $ 227
Commercial other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 3 | 2
Pre-Modification Recorded Investment | $ 1,255 | $ 227
Post-Modification Recorded Investment | $ 1,255 | $ 227
Commercial other [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 0
Pre-Modification Recorded Investment | $ 174 | $ 0
Commercial other [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 2
Pre-Modification Recorded Investment | $ 1,081 | $ 227
Agricultural other [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 0
Pre-Modification Recorded Investment | $ 1,061 | $ 0
Post-Modification Recorded Investment | $ 1,061 | $ 0
Agricultural other [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 0
Pre-Modification Recorded Investment | $ 98 | $ 0
Agricultural other [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 1 | 0
Pre-Modification Recorded Investment | $ 963 | $ 0
Residential real estate senior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 0
Pre-Modification Recorded Investment | $ 167 | $ 0
Post-Modification Recorded Investment | $ 167 | $ 0
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 | 2 | 0
Pre-Modification Recorded Investment | $ 167 | $ 0
Residential real estate junior liens [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 8
Post-Modification Recorded Investment | $ 0 | $ 8
Residential real estate junior liens [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 8
Residential real estate junior liens [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 0
Pre-Modification Recorded Investment | $ 0 | $ 0
Total residential real estate [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 1
Pre-Modification Recorded Investment | $ 167 | $ 8
Post-Modification Recorded Investment | $ 167 | $ 8
Total residential real estate [Member] | Interest Rate Below Market Reduction [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 0 | 1
Pre-Modification Recorded Investment | $ 0 | $ 8
Total residential real estate [Member] | Below Market Interest Rate and Extension of Amortization Period [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number of Loans | loan | 2 | 0
Pre-Modification Recorded Investment | $ 167 | $ 0

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