Loans - Changes in the Allowance for Losses (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance			$ 15,089,000
(Release of)/provision for losses	$ (136,000)	$ 617,000	1,484,000	$ (699,000)
Ending balance	16,614,000		16,614,000
Farm & Ranch
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	3,935,000	2,265,000	4,044,000	2,882,000
(Release of)/provision for losses	(25,000)	(153,000)	(134,000)	(686,000)
Charge-offs	0	0	0	(84,000)
Ending balance	3,910,000	2,112,000	3,910,000	2,112,000
Farm & Ranch | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
(Release of)/provision for losses			1,100,000	0
Farm & Ranch | Operating Segments
Financing Receivable, Allowance for Credit Losses [Roll Forward]
(Release of)/provision for losses	(13,000)	(93,000)	(136,000)	(440,000)
Corporate AgFinance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	7,367,000	1,750,000	2,731,000	560,000
(Release of)/provision for losses	(3,689,000)	334,000	947,000	1,524,000
Charge-offs	0	0	0	0
Ending balance	3,678,000	2,084,000	3,678,000	2,084,000
Corporate AgFinance | Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
(Release of)/provision for losses			0	1,700,000
Corporate AgFinance | Operating Segments
Financing Receivable, Allowance for Credit Losses [Roll Forward]
(Release of)/provision for losses	(3,694,000)	333,000	934,000	1,498,000
Agricultural Finance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	11,302,000	4,015,000	6,775,000	3,442,000
(Release of)/provision for losses	(3,714,000)	181,000	813,000	838,000
Charge-offs	0	0	0	(84,000)
Ending balance	7,588,000	4,196,000	7,588,000	4,196,000
Rural Infrastructure Finance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	5,446,000	8,388,000	8,314,000	10,599,000
(Release of)/provision for losses	3,580,000	418,000	712,000	(1,793,000)
Charge-offs	0	0	0	0
Ending balance	$ 9,026,000	$ 8,806,000	9,026,000	8,806,000
Rural Infrastructure Finance | Collateral Pledged
Financing Receivable, Allowance for Credit Losses [Roll Forward]
(Release of)/provision for losses			$ 0	$ 0