Loans - Changes in the Allowance for Losses (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 15,089,000
Provision for/(release of) losses	547,000	$ 56,000
Ending balance	15,673,000
Farm & Ranch
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	4,044,000	2,882,000
Provision for/(release of) losses	(111,000)	77,000
Charge-offs	0	84,000
Ending balance	3,933,000	2,875,000
Farm & Ranch | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for/(release of) losses	1,100,000	0
Corporate AgFinance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	2,731,000	560,000
Provision for/(release of) losses	4,308,000	513,000
Charge-offs	0	0
Ending balance	7,039,000	1,073,000
Corporate AgFinance | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for/(release of) losses	4,600,000	0
Agricultural Finance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	6,775,000	3,442,000
Provision for/(release of) losses	4,197,000	590,000
Charge-offs	0	84,000
Ending balance	10,972,000	3,948,000
Rural Infrastructure Finance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	8,314,000	10,599,000
Provision for/(release of) losses	(3,613,000)	(977,000)
Charge-offs	0	0
Ending balance	4,701,000	9,622,000
Rural Infrastructure Finance | Collateral Pledged
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Provision for/(release of) losses	$ 0	$ 0