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Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | $ 1,248,558 | $ 1,238,311
Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 757,993 | 756,686
Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 537,016 | 506,297
Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 174,000 | 200,131
Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 46,977 | 50,258
Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 93,782 | 100,461
Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 66,109 | 71,218
Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 27,673 | 29,243
Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 851,775 | 857,147
1 - Excellent [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 161 | 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 | 161 | 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 | 161 | 0
2 - High quality [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 17,590 | 15,714
2 - High quality [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 8,089 | 2,308
2 - High quality [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 9,501 | 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 | 18,060 | 16,266
3 - High satisfactory [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 169,994 | 170,678
3 - High satisfactory [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 79,462 | 69,327
3 - High satisfactory [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 43,555 | 51,093
3 - High satisfactory [Member] | Commercial Advances to Mortgage Brokers Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 46,977 | 50,258
3 - High satisfactory [Member] | Total agricultural [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 13,738 | 19,723
3 - High satisfactory [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 10,553 | 14,411
3 - High satisfactory [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,185 | 5,312
3 - High satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 183,732 | 190,401
4 - Low satisfactory [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 533,103 | 525,758
4 - Low satisfactory [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 421,240 | 403,733
4 - Low satisfactory [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 111,863 | 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 | 50,816 | 52,064
4 - Low satisfactory [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 34,263 | 34,464
4 - Low satisfactory [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 16,553 | 17,600
4 - Low satisfactory [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 583,919 | 577,822
5 - Special mention [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 15,024 | 21,223
5 - Special mention [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 12,880 | 15,049
5 - Special mention [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 2,144 | 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 | 17,618 | 16,377
5 - Special mention [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 13,827 | 13,137
5 - Special mention [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,791 | 3,240
5 - Special mention [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 32,642 | 37,600
6 - Substandard [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 21,960 | 21,984
6 - Substandard [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 15,308 | 15,854
6 - Substandard [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 6,652 | 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 | 8,329 | 7,960
6 - Substandard [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 4,468 | 5,267
6 - Substandard [Member] | Agricultural other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 3,861 | 2,693
6 - Substandard [Member] | Commercial And Agricultural Portfolio Segment [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 30,289 | 29,944
7 - Vulnerable [Member] | Total commercial [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 161 | 1,329
7 - Vulnerable [Member] | Commercial real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 37 | 26
7 - Vulnerable [Member] | Commercial other [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 124 | 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 | 2,811 | 3,595
7 - Vulnerable [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 2,536 | 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 | 2,972 | 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 | 0 | 190
8 - Doubtful [Member] | Agricultural real estate [Member] |  |
Financing Receivable, Credit Quality Indicator [Line Items] |  |
Total | 0 | 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 | 0 | 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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