Loans - Allowance for Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for losses	$ 16,748		$ 15,089
Farm & Ranch
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for losses	3,935	$ 3,933	4,044	$ 2,265	$ 2,875	$ 2,882
Corporate AgFinance
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for losses	7,367	7,039	2,731	1,750	1,073	560
Agricultural Finance
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for losses	11,302	10,972	6,775	4,015	3,948	3,442
Rural Infrastructure Finance
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for losses	$ 5,446	$ 4,701	$ 8,314	$ 8,388	$ 9,622	$ 10,599