LOANS - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) segment	Jun. 30, 2023 USD ($)	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at lower of cost or fair value	$ 0		$ 0			$ 0
Losses on sale of mortgage loans	1,147,000	$ 0	1,147,000	$ 0
Loans, net of allowance	11,786,508,000		$ 11,786,508,000			$ 11,039,349,000
Number of operating segments | segment			7
Provision for/(release of) losses	6,179,000	1,073,000	$ 4,378,000	1,620,000
Rural Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for/(release of) losses	626,000	745,000	(1,337,000)	(2,868,000)
Current period charge-offs	0	0	$ 0	0
Principal balance paydown			15.00%
Agricultural Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of operating segments | segment			2
Provision for/(release of) losses	5,629,000	330,000	$ 5,849,000	4,527,000
Current period charge-offs	4,043,000	0	4,043,000	0
Corporate AgFinance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for/(release of) losses	5,387,000	328,000	5,008,000	4,636,000
Current period charge-offs	3,942,000	$ 0	3,942,000	$ 0
Corporate AgFinance | Agricultural Storage and Processing Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Losses on sale of mortgage loans	1,100,000
Loans sold	7,000,000
Loans, net of allowance	$ 7,400,000		$ 7,400,000		$ 14,400,000