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Loans and ALLL (Summary of information pertaining to impaired loans) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2020 | Jun. 30, 2019 | Jun. 30, 2020 | Jun. 30, 2019 | Dec. 31, 2019
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Outstanding Balance | $ 9,415 |  | $ 9,415 |  | $ 8,782
Impaired loans without a valuation allowance, Outstanding Balance | 16,937 |  | 16,937 |  | 19,409
Impaired loans, Outstanding Balance | 26,352 |  | 26,352 |  | 28,191
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 10,135 |  | 10,135 |  | 9,329
Impaired loans without a valuation allowance, Unpaid Principal Balance | 17,011 |  | 17,011 |  | 20,022
Impaired loans, Unpaid Principal Balance | 27,146 |  | 27,146 |  | 29,351
Impaired loans, Valuation Allowance | 950 |  | 950 |  | 1,114
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 10,174 | $ 10,551 | 10,014 | $ 10,550 |
Impaired loans without a valuation allowance, Average Outstanding Balance | 16,822 | 18,918 | 17,441 | 19,468 |
Impaired loans, Average Outstanding Balance | 26,996 | 29,469 | 27,455 | 30,018 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 116 | 92 | 248 | 215 |
Impaired loans without a valuation allowance, Interest Income Recognized | 234 | 178 | 380 | 335 |
Impaired loans, Interest Income Recognized | 350 | 270 | 628 | 550 |
Total commercial [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Outstanding Balance | 8,235 |  | 8,235 |  | 7,865
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans, Unpaid Principal Balance | 8,551 |  | 8,551 |  | 8,246
Impaired loans, Valuation Allowance | 63 |  | 63 |  | 15
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Average Outstanding Balance | 8,417 | 9,244 | 8,323 | 9,460 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans, Interest Income Recognized | 113 | 41 | 218 | 164 |
Commercial real estate [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Outstanding Balance | 1,045 |  | 1,045 |  | 517
Impaired loans without a valuation allowance, Outstanding Balance | 3,930 |  | 3,930 |  | 4,961
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 1,287 |  | 1,287 |  | 635
Impaired loans without a valuation allowance, Unpaid Principal Balance | 4,004 |  | 4,004 |  | 5,224
Impaired loans, Valuation Allowance | 63 |  | 63 |  | 15
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 1,085 | 2,497 | 951 | 2,952 |
Impaired loans without a valuation allowance, Average Outstanding Balance | 4,046 | 3,985 | 4,304 | 3,636 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 21 | 7 | 46 | 56 |
Impaired loans without a valuation allowance, Interest Income Recognized | 60 | 21 | 119 | 74 |
Commercial other [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Outstanding Balance | 3,260 |  | 3,260 |  | 2,387
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Unpaid Principal Balance | 3,260 |  | 3,260 |  | 2,387
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 460 | 11 | 460 | 11 |
Impaired loans without a valuation allowance, Average Outstanding Balance | 2,826 | 2,751 | 2,608 | 2,861 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 0 | 0 | 6 | 0 |
Impaired loans without a valuation allowance, Interest Income Recognized | 32 | 13 | 47 | 34 |
Total agricultural [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Outstanding Balance | 13,191 |  | 13,191 |  | 14,840
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans, Unpaid Principal Balance | 13,241 |  | 13,241 |  | 14,890
Impaired loans, Valuation Allowance | 63 |  | 63 |  | 26
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Average Outstanding Balance | 13,426 | 13,732 | 13,839 | 13,939 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans, Interest Income Recognized | 189 | 210 | 301 | 293 |
Agricultural real estate [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Outstanding Balance | 2,201 |  | 2,201 |  | 1,509
Impaired loans without a valuation allowance, Outstanding Balance | 7,689 |  | 7,689 |  | 8,372
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 2,251 |  | 2,251 |  | 1,509
Impaired loans without a valuation allowance, Unpaid Principal Balance | 7,689 |  | 7,689 |  | 8,422
Impaired loans, Valuation Allowance | 61 |  | 61 |  | 12
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 2,224 | 951 | 2,051 | 671 |
Impaired loans without a valuation allowance, Average Outstanding Balance | 7,441 | 7,307 | 7,612 | 7,465 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 26 | 57 | 50 | 63 |
Impaired loans without a valuation allowance, Interest Income Recognized | 87 | 58 | 146 | 65 |
Agricultural other [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Outstanding Balance | 1,355 |  | 1,355 |  | 1,355
Impaired loans without a valuation allowance, Outstanding Balance | 1,946 |  | 1,946 |  | 3,604
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 1,355 |  | 1,355 |  | 1,355
Impaired loans without a valuation allowance, Unpaid Principal Balance | 1,946 |  | 1,946 |  | 3,604
Impaired loans, Valuation Allowance | 2 |  | 2 |  | 14
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 1,355 | 641 | 1,355 | 343 |
Impaired loans without a valuation allowance, Average Outstanding Balance | 2,406 | 4,833 | 2,821 | 5,460 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 20 | 9 | 42 | 9 |
Impaired loans without a valuation allowance, Interest Income Recognized | 56 | 86 | 63 | 156 |
Total residential real estate [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Outstanding Balance | 4,926 |  | 4,926 |  | 5,486
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans, Unpaid Principal Balance | 5,354 |  | 5,354 |  | 6,215
Impaired loans, Valuation Allowance | 824 |  | 824 |  | 1,073
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Average Outstanding Balance | 5,151 | 6,485 | 5,291 | 6,611 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans, Interest Income Recognized | 48 | 19 | 109 | 93 |
Residential real estate senior liens [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Outstanding Balance | 4,814 |  | 4,814 |  | 5,401
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 5,242 |  | 5,242 |  | 5,830
Impaired loans, Valuation Allowance | 824 |  | 824 |  | 1,073
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 5,050 | 6,439 | 5,197 | 6,561 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 49 | 19 | 104 | 87 |
Residential real estate junior liens [Member] |  |  |  |  |
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 0 | 12 | 0 | 12 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 0 | 0 | 0 | 0 |
Residential real estate home equity lines of credit [Member] |  |  |  |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Outstanding Balance | 112 |  | 112 |  | 85
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Unpaid Principal Balance | 112 |  | 112 |  | $ 385
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Average Outstanding Balance | 101 | 34 | 94 | 38 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Interest Income Recognized | (1) | 0 | 5 | 6 |
Total Consumer [Member] |  |  |  |  |
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans, Average Outstanding Balance | 2 | 8 | 2 | 8 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans, Interest Income Recognized | 0 | 0 | 0 | 0 |
Consumer secured [Member] |  |  |  |  |
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Average Outstanding Balance | 2 | 8 | 2 | 8 |
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |  |  |  |
Impaired loans without a valuation allowance, Interest Income Recognized | $ 0 | $ 0 | $ 0 | $ 0 |

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