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Loans and ALLL (Summary of information pertaining to TDRs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) loan	Dec. 31, 2019 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	18	11
Pre-Modification Recorded Investment	$ 8,554	$ 4,491
Post-Modification Recorded Investment	$ 8,554	$ 4,491
Commercial other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	10	3
Pre-Modification Recorded Investment	$ 5,224	$ 1,188
Post-Modification Recorded Investment	$ 5,224	$ 1,188
Agricultural other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	5	7
Pre-Modification Recorded Investment	$ 3,194	$ 3,286
Post-Modification Recorded Investment	$ 3,194	$ 3,286
Residential real estate senior liens [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	3	1
Pre-Modification Recorded Investment	$ 136	$ 17
Post-Modification Recorded Investment	$ 136	$ 17
Below Market Interest Rate and Extension of Amortization Period [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	16	9
Pre-Modification Recorded Investment	$ 7,567	$ 3,302
Below Market Interest Rate and Extension of Amortization Period [Member] | Commercial other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	8	3
Pre-Modification Recorded Investment	$ 4,237	$ 1,188
Below Market Interest Rate and Extension of Amortization Period [Member] | Agricultural other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	5	5
Pre-Modification Recorded Investment	$ 3,194	$ 2,097
Below Market Interest Rate and Extension of Amortization Period [Member] | Residential real estate senior liens [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	3	1
Pre-Modification Recorded Investment	$ 136	$ 17
Interest Rate Below Market Reduction [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	2	2
Pre-Modification Recorded Investment	$ 987	$ 1,189
Interest Rate Below Market Reduction [Member] | Commercial other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	2	0
Pre-Modification Recorded Investment	$ 987	$ 0
Interest Rate Below Market Reduction [Member] | Agricultural other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	2
Pre-Modification Recorded Investment	$ 0	$ 1,189
Interest Rate Below Market Reduction [Member] | Residential real estate senior liens [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0	0
Pre-Modification Recorded Investment	$ 0	$ 0

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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