LOANS - Schedule of Unpaid Principal Balances by Delinquency Status (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2026	Sep. 30, 2026	Dec. 31, 2025
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 16,689,890	$ 16,689,890	$ 13,877,051
Nonaccrual Loans	288,129	288,129	238,049
Total Loans	19,459,710	19,459,710	16,706,520
Nonaccrual loans with no associated allowance	46,500	46,500	59,200
Interest received on nonaccrual loans	3,100	18,900	6,500
Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	282,963	282,963	224,662
Total Loans	11,065,063	11,065,063	9,945,439
Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	9,538,817	9,538,817	8,484,748
Nonaccrual Loans	274,608	274,608	179,478
Total Loans	9,538,817	9,538,817	8,484,748
Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,526,246	1,526,246	1,460,691
Nonaccrual Loans	8,355	8,355	45,184
Total Loans	1,526,246	1,526,246	1,460,691
Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,394,647	8,394,647	6,761,081
Nonaccrual Loans	5,166	5,166	13,387
Total Loans	8,394,647	8,394,647	6,761,081
Current
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	19,128,947	19,128,947	16,434,377
Current | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,739,466	10,739,466	9,686,683
Current | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	9,230,342	9,230,342	8,271,176
Current | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	1,509,124	1,509,124	1,415,507
Current | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,389,481	8,389,481	6,747,694
Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	42,634	42,634	34,094
Total Past Due | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	42,634	42,634	34,094
Total Past Due | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	33,867	33,867	34,094
Total Past Due | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,767	8,767	0
Total Past Due | Infrastructure Finance loans
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	15,566	15,566	21,209
30-59 Days | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,566	15,566	21,209
30-59 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	15,566	15,566	21,209
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 | Infrastructure Finance loans
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	10,982	10,982	8,595
60-89 Days | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	10,982	10,982	8,595
60-89 Days | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	2,215	2,215	8,595
60-89 Days | Corporate AgFinance
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	8,767	8,767	0
60-89 Days | Infrastructure Finance loans
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	16,086	16,086	4,290
90 Days and Greater | Total Agricultural Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	16,086	16,086	4,290
90 Days and Greater | Farm & Ranch
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	16,086	16,086	4,290
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 | Infrastructure Finance loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans held for investment, at amortized cost	$ 0	$ 0	$ 0