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Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment [Line Items]
Total	$ 1,301,037	$ 1,238,311
Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	807,439	756,686
Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	570,587	506,297
Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	164,851	200,131
Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	72,001	50,258
Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	93,955	100,461
Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	66,144	71,218
Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	27,811	29,243
Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	901,394	857,147
1 - Excellent [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	300	0
1 - Excellent [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	300	0
1 - Excellent [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
1 - Excellent [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	300	0
2 - High quality [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	15,891	15,714
2 - High quality [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	9,010	2,308
2 - High quality [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,881	13,406
2 - High quality [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
2 - High quality [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	453	552
2 - High quality [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	453	541
2 - High quality [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	11
2 - High quality [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	16,344	16,266
3 - High satisfactory [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	204,223	170,678
3 - High satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	86,135	69,327
3 - High satisfactory [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	46,087	51,093
3 - High satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	72,001	50,258
3 - High satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,656	19,723
3 - High satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	9,361	14,411
3 - High satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	4,295	5,312
3 - High satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	217,879	190,401
4 - Low satisfactory [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	552,864	525,758
4 - Low satisfactory [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	448,489	403,733
4 - Low satisfactory [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	104,375	122,025
4 - Low satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
4 - Low satisfactory [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	52,469	52,064
4 - Low satisfactory [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	36,483	34,464
4 - Low satisfactory [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	15,986	17,600
4 - Low satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	605,333	577,822
5 - Special mention [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	14,563	21,223
5 - Special mention [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,212	15,049
5 - Special mention [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,351	6,174
5 - Special mention [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
5 - Special mention [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	16,548	16,377
5 - Special mention [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,096	13,137
5 - Special mention [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,452	3,240
5 - Special mention [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	31,111	37,600
6 - Substandard [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	19,257	21,984
6 - Substandard [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	13,519	15,854
6 - Substandard [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	5,738	6,130
6 - Substandard [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
6 - Substandard [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	10,055	7,960
6 - Substandard [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	6,252	5,267
6 - Substandard [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	3,803	2,693
6 - Substandard [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	29,312	29,944
7 - Vulnerable [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	341	1,329
7 - Vulnerable [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	222	26
7 - Vulnerable [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	119	1,303
7 - Vulnerable [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
7 - Vulnerable [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	774	3,595
7 - Vulnerable [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	499	3,208
7 - Vulnerable [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	275	387
7 - Vulnerable [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	1,115	4,924
8 - Doubtful [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	190
8 - Doubtful [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	190
8 - Doubtful [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
8 - Doubtful [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	190
Loss [Member] | Total commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Commercial real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Commercial other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Commercial Advances to Mortgage Brokers Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Total agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Agricultural real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Agricultural other [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	0	0
Loss [Member] | Commercial And Agricultural Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total	$ 0	$ 0

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