LOANS - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 9,623,119	$ 9,008,979
Nonaccrual loans	65,236	78,965
Total loans	11,360,197	10,549,845
Nonaccrual loans with no associated allowance	25,700	22,000
Interest received on nonaccrual loans	2,600	5,600
Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	65,236	78,965
Total loans	7,825,434	7,528,579
Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,565,711	6,362,326
Nonaccrual loans	65,236	63,402
Total loans	6,565,711	6,362,326
Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,259,723	1,166,253
Nonaccrual loans	0	15,563
Total loans	1,259,723	1,166,253
Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,534,763	3,021,266
Nonaccrual loans	0	0
Total loans	3,534,763	3,021,266
Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	11,264,691	10,459,282
Current | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	7,729,928	7,438,016
Current | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,470,205	6,287,326
Current | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,259,723	1,150,690
Current | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,534,763	3,021,266
Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	30,270	11,598
Total Past Due | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	30,270	11,598
Total Past Due | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	30,270	11,598
Total Past Due | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
Total Past Due | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,326	10,066
30-59 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,326	10,066
30-59 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,326	10,066
30-59 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
30-59 Days | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,953	392
60-89 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,953	392
60-89 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,953	392
60-89 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
60-89 Days | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
90 Days and Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,991	1,140
90 Days and Greater | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,991	1,140
90 Days and Greater | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,991	1,140
90 Days and Greater | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	0
90 Days and Greater | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 0	$ 0