SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Consolidation of Variable Interest Entities (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	$ 11,636,815	$ 11,183,408
Debt securities of consolidated trusts held by third parties	28,049,766	27,520,173
Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	5,623,384	5,514,546
Investment securities
Variable Interest Entity [Line Items]
Carrying value	6,230,080	5,953,014
Agricultural Finance
Variable Interest Entity [Line Items]
Borrower remittances	200	4,700
Unamortized discount	110,500	113,200
Consolidated VIE \| On-balance sheet
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	2,005,680	2,038,283
Debt securities of consolidated trusts held by third parties	1,894,920	1,929,628
Consolidated VIE \| On-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost		2,038,283
Debt securities of consolidated trusts held by third parties		1,929,628
Consolidated VIE \| On-balance sheet \| Treasury
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost		0
Debt securities of consolidated trusts held by third parties		0
Consolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	2,005,680
Debt securities of consolidated trusts held by third parties	1,894,920
Consolidated VIE \| Corporate, non-segment \| On-balance sheet
Variable Interest Entity [Line Items]
Loans held for investment in consolidated trusts, at amortized cost	0
Debt securities of consolidated trusts held by third parties	0
Unconsolidated VIE \| On-balance sheet \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	58,580	59,317
Maximum exposure to loss	58,219	58,985
Unconsolidated VIE \| On-balance sheet \| Investment securities
Variable Interest Entity [Line Items]
Carrying value	4,476,698	4,212,258
Maximum exposure to loss	4,730,044	4,547,397
Unconsolidated VIE \| On-balance sheet \| Agricultural Finance \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value		59,317
Maximum exposure to loss		58,985
Unconsolidated VIE \| On-balance sheet \| Agricultural Finance \| Investment securities
Variable Interest Entity [Line Items]
Carrying value		0
Maximum exposure to loss		0
Unconsolidated VIE \| On-balance sheet \| Treasury \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value		0
Maximum exposure to loss		0
Unconsolidated VIE \| On-balance sheet \| Treasury \| Investment securities
Variable Interest Entity [Line Items]
Carrying value		4,212,258
Maximum exposure to loss		4,547,397
Unconsolidated VIE \| Off-balance sheet
Variable Interest Entity [Line Items]
Maximum exposure to loss	414,291	426,310
Unconsolidated VIE \| Off-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Maximum exposure to loss		426,310
Unconsolidated VIE \| Off-balance sheet \| Treasury
Variable Interest Entity [Line Items]
Maximum exposure to loss		$ 0
Unconsolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	58,580
Maximum exposure to loss	58,219
Unconsolidated VIE \| Operating Segments \| On-balance sheet \| Agricultural Finance \| Investment securities
Variable Interest Entity [Line Items]
Carrying value	0
Maximum exposure to loss	0
Unconsolidated VIE \| Operating Segments \| Off-balance sheet \| Agricultural Finance
Variable Interest Entity [Line Items]
Maximum exposure to loss	414,291
Unconsolidated VIE \| Corporate, non-segment \| On-balance sheet \| Farmer Mac Guaranteed Securities
Variable Interest Entity [Line Items]
Carrying value	0
Maximum exposure to loss	0
Unconsolidated VIE \| Corporate, non-segment \| On-balance sheet \| Investment securities
Variable Interest Entity [Line Items]
Carrying value	4,476,698
Maximum exposure to loss	4,730,044
Unconsolidated VIE \| Corporate, non-segment \| Off-balance sheet
Variable Interest Entity [Line Items]
Maximum exposure to loss	$ 0

Amount, after accumulated amortization, of debt discount.

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