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Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) - USD ($) $ in Thousands | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | $ 1,206,663 | $ 1,238,311
Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 723,888 | 756,686
Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 520,206 | 506,297
Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 203,682 | 200,131
Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 50,258
Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 95,197 | 100,461
Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 68,508 | 71,218
Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 26,689 | 29,243
Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 819,085 | 857,147
1 - Excellent [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
1 - Excellent [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
2 - High quality [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 17,580 | 15,714
2 - High quality [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 6,845 | 2,308
2 - High quality [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 10,735 | 13,406
2 - High quality [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
2 - High quality [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 470 | 552
2 - High quality [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 462 | 541
2 - High quality [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 8 | 11
2 - High quality [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 18,050 | 16,266
3 - High satisfactory [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 130,887 | 170,678
3 - High satisfactory [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 79,146 | 69,327
3 - High satisfactory [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 51,741 | 51,093
3 - High satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 50,258
3 - High satisfactory [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 14,009 | 19,723
3 - High satisfactory [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 10,646 | 14,411
3 - High satisfactory [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,363 | 5,312
3 - High satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 144,896 | 190,401
4 - Low satisfactory [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 539,001 | 525,758
4 - Low satisfactory [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 407,904 | 403,733
4 - Low satisfactory [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 131,097 | 122,025
4 - Low satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
4 - Low satisfactory [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 51,668 | 52,064
4 - Low satisfactory [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 36,299 | 34,464
4 - Low satisfactory [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 15,369 | 17,600
4 - Low satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 590,669 | 577,822
5 - Special mention [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 12,878 | 21,223
5 - Special mention [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 10,528 | 15,049
5 - Special mention [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 2,350 | 6,174
5 - Special mention [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
5 - Special mention [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 17,674 | 16,377
5 - Special mention [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 13,808 | 13,137
5 - Special mention [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,866 | 3,240
5 - Special mention [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 30,552 | 37,600
6 - Substandard [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 23,360 | 21,984
6 - Substandard [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 15,738 | 15,854
6 - Substandard [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 7,622 | 6,130
6 - Substandard [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
6 - Substandard [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 8,362 | 7,960
6 - Substandard [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 4,554 | 5,267
6 - Substandard [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,808 | 2,693
6 - Substandard [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 31,722 | 29,944
7 - Vulnerable [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 182 | 1,329
7 - Vulnerable [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 45 | 26
7 - Vulnerable [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 137 | 1,303
7 - Vulnerable [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
7 - Vulnerable [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 2,826 | 3,595
7 - Vulnerable [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 2,551 | 3,208
7 - Vulnerable [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 275 | 387
7 - Vulnerable [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,008 | 4,924
8 - Doubtful [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
8 - Doubtful [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
8 - Doubtful [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
8 - Doubtful [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
8 - Doubtful [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 188 | 190
8 - Doubtful [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 188 | 190
8 - Doubtful [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
8 - Doubtful [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 188 | 190
Loss [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 0
Loss [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | $ 0 | $ 0

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