FAIR VALUE DISCLOSURES - Schedule of Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Income	Net Income
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Comprehensive Income (Loss), Net of Tax, Attributable to Parent	Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 5,540,222	$ 5,558,633
Purchases	300,000	50,000
Settlements	(276,289)	(64,391)
Allowance for Losses	50	28
Realized and unrealized gains (losses) included in Income	82,075	(80,708)
Unrealized (losses)/gains included in Other Comprehensive Income	2,627	29,206
Ending Balance	5,648,685	5,492,768
Available-for-sale securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,476	19,082
Purchases	0	0
Settlements	0	0
Allowance for Losses	0	1
Realized and unrealized gains (losses) included in Income	0	0
Unrealized (losses)/gains included in Other Comprehensive Income	(123)	198
Ending Balance	19,353	19,281
Floating rate auction-rate certificates backed by Government guaranteed student loans | Floating interest rate | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,476	19,082
Purchases	0	0
Settlements	0	0
Allowance for Losses	0	1
Realized and unrealized gains (losses) included in Income	0	0
Unrealized (losses)/gains included in Other Comprehensive Income	(123)	198
Ending Balance	19,353	19,281
Farmer Mac Guaranteed Securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,514,546	5,532,479
Purchases	300,000	50,000
Settlements	(276,028)	(64,132)
Allowance for Losses	50	27
Realized and unrealized gains (losses) included in Income	82,066	(80,694)
Unrealized (losses)/gains included in Other Comprehensive Income	2,750	29,008
Ending Balance	5,623,384	5,466,688
Farmer Mac Guaranteed Securities | Level 3 | Recurring | AgVantage
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,505,531	5,522,712
Purchases	300,000	50,000
Settlements	(275,854)	(63,955)
Allowance for Losses	50	27
Realized and unrealized gains (losses) included in Income	82,066	(80,694)
Unrealized (losses)/gains included in Other Comprehensive Income	2,719	29,107
Ending Balance	5,614,512	5,457,197
Farmer Mac Guaranteed Securities | Level 3 | Recurring | Farmer Mac Guaranteed USDA Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9,015	9,767
Purchases	0	0
Settlements	(174)	(177)
Allowance for Losses	0	0
Realized and unrealized gains (losses) included in Income	0	0
Unrealized (losses)/gains included in Other Comprehensive Income	31	(99)
Ending Balance	8,872	9,491
USDA Securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	818	1,241
Purchases	0	0
Settlements	(175)	(174)
Allowance for Losses	0	0
Realized and unrealized gains (losses) included in Income	8	(1)
Unrealized (losses)/gains included in Other Comprehensive Income	0	0
Ending Balance	651	1,066
Guarantee and commitment obligations: | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,382	5,831
Purchases	0	0
Settlements	(86)	(85)
Allowance for Losses	0	0
Realized and unrealized gains (losses) included in Income	1	(13)
Unrealized (losses)/gains included in Other Comprehensive Income	0	0
Ending Balance	5,297	5,733
Guarantee and commitment obligations: | Level 3 | Recurring | Guarantee Asset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,382	5,831
Purchases	0	0
Settlements	(86)	(85)
Allowance for Losses	0	0
Realized and unrealized gains (losses) included in Income	1	(13)
Unrealized (losses)/gains included in Other Comprehensive Income	0	0
Ending Balance	$ 5,297	$ 5,733