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Loans and ALLL (Summary of information pertaining to impaired loans) (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | $ 9,823 | $ 8,782
Impaired loans without a valuation allowance, Outstanding Balance | 18,113 | 19,409
Impaired loans, Outstanding Balance | 27,936 | 28,191
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 10,407 | 9,329
Impaired loans without a valuation allowance, Unpaid Principal Balance | 18,237 | 20,022
Impaired loans, Unpaid Principal Balance | 28,644 | 29,351
Impaired loans, Valuation Allowance | 911 | 1,114
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 10,138 | 10,198
Impaired loans without a valuation allowance, Average Outstanding Balance | 17,536 | 19,034
Impaired loans, Average Outstanding Balance | 27,674 | 29,232
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 519 | 330
Impaired loans without a valuation allowance, Interest Income Recognized | 772 | 572
Impaired loans, Interest Income Recognized | 1,291 | 902
Total commercial [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans, Outstanding Balance | 9,821 | 7,865
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans, Unpaid Principal Balance | 10,137 | 8,246
Impaired loans, Valuation Allowance | 84 | 15
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans, Average Outstanding Balance | 9,257 | 8,998
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans, Interest Income Recognized | 501 | 198
Commercial real estate [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 2,048 | 517
Impaired loans without a valuation allowance, Outstanding Balance | 3,006 | 4,961
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 2,290 | 635
Impaired loans without a valuation allowance, Unpaid Principal Balance | 3,080 | 5,224
Impaired loans, Valuation Allowance | 79 | 15
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 1,384 | 2,044
Impaired loans without a valuation allowance, Average Outstanding Balance | 3,679 | 4,247
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 121 | 61
Impaired loans without a valuation allowance, Interest Income Recognized | 210 | 91
Commercial other [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 107 | 0
Impaired loans without a valuation allowance, Outstanding Balance | 4,660 | 2,387
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 107 | 0
Impaired loans without a valuation allowance, Unpaid Principal Balance | 4,660 | 2,387
Impaired loans, Valuation Allowance | 5 | 0
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 464 | 10
Impaired loans without a valuation allowance, Average Outstanding Balance | 3,730 | 2,697
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 20 | 0
Impaired loans without a valuation allowance, Interest Income Recognized | 150 | 46
Total agricultural [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans, Outstanding Balance | 13,796 | 14,840
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans, Unpaid Principal Balance | 13,846 | 14,890
Impaired loans, Valuation Allowance | 56 | 26
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans, Average Outstanding Balance | 13,519 | 13,950
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans, Interest Income Recognized | 588 | 584
Agricultural real estate [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 1,994 | 1,509
Impaired loans without a valuation allowance, Outstanding Balance | 8,681 | 8,372
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 1,994 | 1,509
Impaired loans without a valuation allowance, Unpaid Principal Balance | 8,731 | 8,422
Impaired loans, Valuation Allowance | 54 | 12
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 2,099 | 1,091
Impaired loans without a valuation allowance, Average Outstanding Balance | 7,704 | 7,404
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 103 | 100
Impaired loans without a valuation allowance, Interest Income Recognized | 302 | 171
Agricultural other [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 1,355 | 1,355
Impaired loans without a valuation allowance, Outstanding Balance | 1,766 | 3,604
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 1,355 | 1,355
Impaired loans without a valuation allowance, Unpaid Principal Balance | 1,766 | 3,604
Impaired loans, Valuation Allowance | 2 | 14
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 1,355 | 832
Impaired loans without a valuation allowance, Average Outstanding Balance | 2,361 | 4,623
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 78 | 55
Impaired loans without a valuation allowance, Interest Income Recognized | 105 | 258
Total residential real estate [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans, Outstanding Balance | 4,319 | 5,486
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans, Unpaid Principal Balance | 4,661 | 6,215
Impaired loans, Valuation Allowance | 771 | 1,073
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans, Average Outstanding Balance | 4,897 | 6,279
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans, Interest Income Recognized | 202 | 120
Residential real estate senior liens [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 4,319 | 5,401
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 4,661 | 5,830
Impaired loans, Valuation Allowance | 771 | 1,073
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 4,836 | 6,210
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 197 | 114
Residential real estate junior liens [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Outstanding Balance | 0 | 0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans with a valuation allowance, Unpaid Principal Balance | 0 | 0
Impaired loans, Valuation Allowance | 0 | 0
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans with a valuation allowance, Average Outstanding Balance | 0 | 11
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans with a valuation allowance, Interest Income Recognized | 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 | 0 | 85
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans without a valuation allowance, Unpaid Principal Balance | 0 | 385
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans without a valuation allowance, Average Outstanding Balance | 61 | 58
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans without a valuation allowance, Interest Income Recognized | 5 | 6
Total consumer [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans, Outstanding Balance | 0 | 0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans, Unpaid Principal Balance | 0 | 0
Impaired loans, Valuation Allowance | 0 | 0
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans, Average Outstanding Balance | 1 | 5
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans, Interest Income Recognized | 0 | 0
Consumer secured [Member] |  |
Impaired Financing Receivable, Recorded Investment [Abstract] |  |
Impaired loans without a valuation allowance, Outstanding Balance | 0 | 0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract] |  |
Impaired loans without a valuation allowance, Unpaid Principal Balance | 0 | 0
Impaired Financing Receivable, Average Recorded Investment [Abstract] |  |
Impaired loans without a valuation allowance, Average Outstanding Balance | 1 | 5
Impaired Financing Receivable, Interest Income, Accrual Method [Abstract] |  |
Impaired loans without a valuation allowance, Interest Income Recognized | $ 0 | $ 0

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