LOANS - Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 10,041,653	$ 10,041,653	$ 9,623,119
Nonaccrual loans	96,852	96,852	65,236
Total loans	12,165,579	12,165,579	11,360,197
Nonaccrual loans with no associated allowance	26,200	26,200	25,700
Interest received on nonaccrual loans	1,200	1,700	2,600
Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans	96,852	96,852	65,236
Total loans	8,186,341	8,186,341	7,825,434
Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,900,174	6,900,174	6,565,711
Nonaccrual loans	81,817	81,817	65,236
Total loans	6,900,174	6,900,174	6,565,711
Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,286,167	1,286,167	1,259,723
Nonaccrual loans	15,035	15,035	0
Total loans	1,286,167	1,286,167	1,259,723
Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,979,238	3,979,238	3,534,763
Nonaccrual loans	0	0	0
Total loans	3,979,238	3,979,238	3,534,763
Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	12,021,148	12,021,148	11,264,691
Current | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,041,910	8,041,910	7,729,928
Current | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,770,778	6,770,778	6,470,205
Current | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,271,132	1,271,132	1,259,723
Current | Rural Infrastructure Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	3,979,238	3,979,238	3,534,763
Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	47,579	47,579	30,270
Total Past Due | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	47,579	47,579	30,270
Total Past Due | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	47,579	47,579	30,270
Total Past Due | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	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	0
30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	21,101	21,101	15,326
30-59 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	21,101	21,101	15,326
30-59 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	21,101	21,101	15,326
30-59 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	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	0
60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,711	6,711	3,953
60-89 Days | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,711	6,711	3,953
60-89 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	6,711	6,711	3,953
60-89 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	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	0
90 Days and Greater
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	19,767	19,767	10,991
90 Days and Greater | Agricultural Finance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	19,767	19,767	10,991
90 Days and Greater | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	19,767	19,767	10,991
90 Days and Greater | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	0	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	$ 0