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Loans and ALLL (Past due and current loans) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	$ 0	$ 0
Nonaccrual	4,532	5,313
Total Past Due and Nonaccrual	5,863	9,610
Current	1,190,055	1,228,701
Total	1,195,918	1,238,311
Total commercial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	1,328	1,329
Total Past Due and Nonaccrual	1,434	2,148
Current	724,106	754,538
Total	725,540	756,686
Commercial real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	46	26
Total Past Due and Nonaccrual	110	359
Current	507,578	505,938
Total	507,688	506,297
Commercial other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	1,282	1,303
Total Past Due and Nonaccrual	1,324	1,789
Current	207,071	198,342
Total	208,395	200,131
Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	0	0
Current	9,457	50,258
Total	9,457	50,258
Total agricultural [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	3,051	3,785
Total Past Due and Nonaccrual	3,051	3,786
Current	88,578	96,675
Total	91,629	100,461
Agricultural real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	2,775	3,398
Total Past Due and Nonaccrual	2,775	3,398
Current	65,097	67,820
Total	67,872	71,218
Agricultural other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	276	387
Total Past Due and Nonaccrual	276	388
Current	23,481	28,855
Total	23,757	29,243
Total residential real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	153	199
Total Past Due and Nonaccrual	1,344	3,580
Current	304,565	303,963
Total	305,909	307,543
Residential real estate senior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	153	199
Total Past Due and Nonaccrual	1,310	3,547
Current	270,688	269,425
Total	271,998	272,972
Residential real estate junior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	0	25
Current	3,533	3,791
Total	3,533	3,816
Residential real estate home equity lines of credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	34	8
Current	30,344	30,747
Total	30,378	30,755
Total Consumer [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	34	96
Current	72,806	73,525
Total	72,840	73,621
Consumer secured [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	30	93
Current	69,873	70,349
Total	69,903	70,442
Consumer Unsecured Financing Receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
Nonaccrual	0	0
Total Past Due and Nonaccrual	4	3
Current	2,933	3,176
Total	2,937	3,179
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,263	4,152
Financial Asset, 30 to 59 Days Past Due [Member] | Total commercial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	42	819
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	333
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	42	486
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Total agricultural [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	1
Financial Asset, 30 to 59 Days Past Due [Member] | Agricultural real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Agricultural other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	1
Financial Asset, 30 to 59 Days Past Due [Member] | Total residential real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,187	3,236
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate senior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,153	3,203
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate junior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	25
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate home equity lines of credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	34	8
Financial Asset, 30 to 59 Days Past Due [Member] | Total Consumer [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	34	96
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer secured [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	30	93
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Unsecured Financing Receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4	3
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	68	145
Financial Asset, 60 to 89 Days Past Due [Member] | Total commercial [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	64	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	64	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Total agricultural [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Agricultural real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Agricultural other [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Total residential real estate [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4	145
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate senior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4	145
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate junior liens [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate home equity lines of credit [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Total Consumer [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer secured [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Unsecured Financing Receivable [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 0	$ 0

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