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Loans and ALLL (Summary of recorded investment in loans by segments) (Details) - USD ($) $ in Thousands | Mar. 31, 2018 | Dec. 31, 2017 | Mar. 31, 2017 | Dec. 31, 2016
--- | --- | --- | --- | ---
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | $ 2,503 | $ 2,130 |  |
Collectively evaluated for impairment, ALLL | 5,697 | 5,570 |  |
Total, ALLL | 8,200 | 7,700 | $ 7,500 | $ 7,400
Individually evaluated for impairment, Loans | 31,095 | 26,653 |  |
Collectively evaluated for impairment, Loans | 1,061,907 | 1,064,866 |  |
Total | 1,093,002 | 1,091,519 |  |
Commercial [Member] |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | 842 | 650 |  |
Collectively evaluated for impairment, ALLL | 998 | 1,056 |  |
Total, ALLL | 1,840 | 1,706 | 1,771 | 1,814
Individually evaluated for impairment, Loans | 11,675 | 8,099 |  |
Collectively evaluated for impairment, Loans | 631,961 | 626,660 |  |
Total | 643,636 | 634,759 |  |
Agricultural [Member] |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | 141 | 0 |  |
Collectively evaluated for impairment, ALLL | 1,083 | 611 |  |
Total, ALLL | 1,224 | 611 | 527 | 884
Individually evaluated for impairment, Loans | 11,468 | 10,598 |  |
Collectively evaluated for impairment, Loans | 110,862 | 117,671 |  |
Total | 122,330 | 128,269 |  |
Residential Real Estate [Member] |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | 1,520 | 1,480 |  |
Collectively evaluated for impairment, ALLL | 962 | 1,083 |  |
Total, ALLL | 2,482 | 2,563 | 3,098 | 2,664
Individually evaluated for impairment, Loans | 7,940 | 7,939 |  |
Collectively evaluated for impairment, Loans | 262,210 | 264,429 |  |
Total | 270,150 | 272,368 |  |
Total Consumer [Member] |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | 0 | 0 |  |
Collectively evaluated for impairment, ALLL | 795 | 900 |  |
Total, ALLL | 795 | 900 | 671 | 624
Individually evaluated for impairment, Loans | 12 | 17 |  |
Collectively evaluated for impairment, Loans | 56,874 | 56,106 |  |
Total | 56,886 | 56,123 |  |
Unallocated [Member] |  |  |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |  |  |
Individually evaluated for impairment, ALLL | 0 | 0 |  |
Collectively evaluated for impairment, ALLL | 1,859 | 1,920 |  |
Total, ALLL | $ 1,859 | $ 1,920 | $ 1,433 | $ 1,414

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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 The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + 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 (g) -URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953423-111524 + Details
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- Definition Amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date. Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. Excludes amounts related to receivables held-for-sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10(3)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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