Loans - Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details)	12 Months Ended
	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