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Loans and ALLL (Summary of changes in ALLL by segments) (Details) - USD ($) $ in Thousands | 3 Months Ended
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Mar. 31, 2018 | Mar. 31, 2017
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | $ 7,700 | $ 7,400
Allowance for loan losses, Charge-offs | (103) | (144)
Allowance for loan losses, Recoveries | 219 | 217
Allowance for loan losses, Provision for loan losses | 384 | 27
Allowance for loan losses, Ending Balance | 8,200 | 7,500
Commercial [Member] |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | 1,706 | 1,814
Allowance for loan losses, Charge-offs | (5) | (27)
Allowance for loan losses, Recoveries | 103 | 133
Allowance for loan losses, Provision for loan losses | 36 | (149)
Allowance for loan losses, Ending Balance | 1,840 | 1,771
Agricultural [Member] |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | 611 | 884
Allowance for loan losses, Charge-offs | 0 | 0
Allowance for loan losses, Recoveries | 0 | 0
Allowance for loan losses, Provision for loan losses | 613 | (357)
Allowance for loan losses, Ending Balance | 1,224 | 527
Residential Real Estate [Member] |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | 2,563 | 2,664
Allowance for loan losses, Charge-offs | (10) | (43)
Allowance for loan losses, Recoveries | 56 | 36
Allowance for loan losses, Provision for loan losses | (127) | 441
Allowance for loan losses, Ending Balance | 2,482 | 3,098
Consumer Portfolio Segment [Member] |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | 900 | 624
Allowance for loan losses, Charge-offs | (88) | (74)
Allowance for loan losses, Recoveries | 60 | 48
Allowance for loan losses, Provision for loan losses | (77) | 73
Allowance for loan losses, Ending Balance | 795 | 671
Unallocated [Member] |  |
Summary of changes in the ALLL and the recorded investment in loans by segments |  |
Allowance for loan losses, Beginning Balance | 1,920 | 1,414
Allowance for loan losses, Charge-offs | 0 | 0
Allowance for loan losses, Recoveries | 0 | 0
Allowance for loan losses, Provision for loan losses | (61) | 19
Allowance for loan losses, Ending Balance | $ 1,859 | $ 1,433

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- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
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- Definition A valuation allowance for financing receivables that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
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- Definition Amount of recovery of financing receivables doubtful of collection that were previously charged off. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
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- Definition Amount of direct write-downs of financing receivables charged against the allowance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
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- Definition Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 + Details
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