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Loans - Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details) | 12 Months Ended
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Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) note
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Loans renegotiated in troubled debt restructurings | $ 6,200,000 | $ 14,500,000 |
Loans renegotiated in troubled debt restructurings, non-accrual loans | 3,900,000 | 11,300,000 |
Loans renegotiated in troubled debt restructurings, accrual loans | 2,300,000 | 3,200,000 |
Number of notes under troubled debt restructurings | note |  |  | 11
Charge-offs directly related to modified loans | 0 | 0 | $ 0
Financing Receivable, Troubled Debt Restructuring, Postmodification | 0 |  | $ 10,400,000
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend | 0 |  |
Balance of notes for which there was a payment default | 0 |  |
Impaired Financing Receivable, Recorded Investment | 43,500,000 |  |
Financing Receivable, Allowance for Credit Loss, Noncurrent | $ 2,900,000 |  |
Commercial Real Estate Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Number of notes under troubled debt restructurings | note |  |  | 4
Financing Receivable, Troubled Debt Restructuring, Postmodification |  |  | $ 3,300,000
Impaired Financing Receivable, Recorded Investment |  | 23,700,000 |
Agricultural Real Estate Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Impaired Financing Receivable, Recorded Investment |  | 8,200,000 |
Real Estate Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Impaired Financing Receivable, Recorded Investment |  | 41,100,000 |
Commercial Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Number of notes under troubled debt restructurings | note |  |  | 1
Concessions in troubled debt restructurings, amount |  |  | $ 5,000,000.0
Impaired Financing Receivable, Recorded Investment |  | 17,300,000 |
Real Estate Construction Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Impaired Financing Receivable, Recorded Investment |  | 3,500,000 |
Agricultural Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Number of notes under troubled debt restructurings | note |  |  | 6
Concessions in troubled debt restructurings, amount |  |  | $ 2,100,000
Impaired Financing Receivable, Recorded Investment |  | $ 6,300,000 |
Interest Only Period Concession |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 200,000
Interest Only Period Concession | Commercial Real Estate Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 200,000
Interest Only Period Concession | Commercial Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Interest Only Period Concession | Agricultural Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Extension of terms or maturity |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Financing Receivable, Troubled Debt Restructuring, Postmodification |  |  | 200,000
Extension of terms or maturity | Commercial Real Estate Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Financing Receivable, Troubled Debt Restructuring, Postmodification |  |  | 200,000
Extension of terms or maturity | Commercial Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Extension of terms or maturity | Agricultural Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Interest rate adjustment |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Interest rate adjustment | Commercial Real Estate Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Interest rate adjustment | Commercial Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Interest rate adjustment | Agricultural Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 0
Other |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Financing Receivable, Troubled Debt Restructuring, Postmodification |  |  | 10,000,000.0
Other | Commercial Real Estate Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Financing Receivable, Troubled Debt Restructuring, Postmodification |  |  | 2,900,000
Other | Commercial Portfolio Segment [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | 5,000,000.0
Other | Agricultural Financing Receivable [Member] |  |  |
Loans and Leases Receivable, Troubled Debt Restructuring |  |  |
Concessions in troubled debt restructurings, amount |  |  | $ 2,100,000

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