LOANS - Schedule of Composition of Loan Balances (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	$ 18,619,095		$ 16,706,520
Allowance for losses	(47,167)	$ (39,920)	(37,785)	$ (29,956)	$ (25,056)	$ (23,223)
Total loans, net of allowance	18,180,844		16,321,276
Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	18,619,095		16,706,520
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	(391,084)		(347,459)
Total loans	18,228,011		16,359,061
Allowance for losses	(47,167)		(37,785)
Total loans, net of allowance	18,180,844		16,321,276
Agricultural Finance loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	10,865,223		9,945,439
Agricultural Finance loans | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	10,865,223		9,945,439
Farm & Ranch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	9,352,264		8,484,748
Allowance for losses	(15,472)	(12,324)	(9,400)	(6,635)	(5,071)	(5,132)
Farm & Ranch | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	9,352,264		8,484,748
Allowance for losses	(15,472)		(9,400)
Corporate AgFinance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	1,512,959		1,460,691
Allowance for losses	(7,211)	(6,421)	(6,631)	(6,943)	(6,298)	(5,379)
Corporate AgFinance | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	1,512,959		1,460,691
Allowance for losses	(7,211)		(6,631)
Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	7,753,872		6,761,081
Allowance for losses	(24,484)	$ (21,175)	(21,754)	$ (16,378)	$ (13,687)	$ (12,712)
Infrastructure Finance | Real Estate Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	7,753,872		6,761,081
Allowance for losses	(24,484)		(21,754)
Unsecuritized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	16,293,297		14,224,510
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	(391,084)		(347,459)
Total loans	15,902,213		13,877,051
Allowance for losses	(45,213)		(36,673)
Total loans, net of allowance	15,857,000		13,840,378
Unsecuritized | Agricultural Finance loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	8,539,425		7,463,429
Unsecuritized | Farm & Ranch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	7,026,466		6,002,738
Unsecuritized | Corporate AgFinance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	1,512,959		1,460,691
Unsecuritized | Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	7,753,872		6,761,081
In Consolidated Trusts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	2,325,798		2,482,010
Unamortized premiums, discounts, fair value hedge basis adjustment, and other cost basis adjustments	0		0
Total loans	2,325,798		2,482,010
Allowance for losses	(1,954)		(1,112)
Total loans, net of allowance	2,323,844		2,480,898
In Consolidated Trusts | Agricultural Finance loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	2,325,798		2,482,010
In Consolidated Trusts | Farm & Ranch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	2,325,798		2,482,010
In Consolidated Trusts | Corporate AgFinance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	0		0
In Consolidated Trusts | Infrastructure Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total unpaid principal balance	$ 0		$ 0