FAIR VALUE DISCLOSURES - Schedule of Unobservable Input Reconciliation (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 01, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
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	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	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	$ 7,770,126	$ 5,425,214	$ 7,770,126	$ 5,558,633	$ 7,632,487
Purchases		400,000	100,000	675,000	1,639,650
Settlements		(216,315)	(7,172)	(561,836)	(1,407,702)
Allowance for Losses		44	134	102	179
Realized and unrealized (losses)/gains included in Income		189,288	(106,203)	102,032	(114,431)
Unrealized gains/(losses) included in Other Comprehensive Income		(10,664)	12,206	13,636	18,908
Transfers Out			(2,684,096)		(2,684,096)
Ending Balance		5,787,567	5,084,995	5,787,567	5,084,995
Available-for-sale securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,032	19,478	19,032	19,082	19,027
Purchases		0	0	0	0
Settlements		0	0	0	0
Allowance for Losses		0	1	2	6
Realized and unrealized (losses)/gains included in Income		0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income		0	0	394	0
Transfers Out			0		0
Ending Balance		19,478	19,033	19,478	19,033
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	19,032	19,478	19,032	19,082	19,027
Purchases		0	0	0	0
Settlements		0	0	0	0
Allowance for Losses		0	1	2	6
Realized and unrealized (losses)/gains included in Income		0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income		0	0	394	0
Transfers Out			0		0
Ending Balance		19,478	19,033	19,478	19,033
Farmer Mac Guaranteed Securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	7,745,415	5,399,151	7,745,415	5,532,479	7,607,226
Purchases		400,000	100,000	675,000	1,639,650
Settlements		(216,031)	(7,044)	(561,166)	(1,406,717)
Allowance for Losses		44	133	100	173
Realized and unrealized (losses)/gains included in Income		189,191	(107,917)	102,036	(116,447)
Unrealized gains/(losses) included in Other Comprehensive Income		(10,664)	12,206	13,242	18,908
Transfers Out			(2,684,096)		(2,684,096)
Ending Balance		5,761,691	5,058,697	5,761,691	5,058,697
Farmer Mac Guaranteed Securities | Level 3 | Recurring | AgVantage Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	7,737,810	5,389,841	7,737,810	5,522,712	7,599,379
Purchases		400,000	100,000	675,000	1,639,650
Settlements		(215,855)	(6,875)	(560,643)	(1,405,674)
Allowance for Losses		44	133	100	173
Realized and unrealized (losses)/gains included in Income		189,191	(107,917)	102,036	(116,447)
Unrealized gains/(losses) included in Other Comprehensive Income		(10,836)	9,653	13,180	15,723
Transfers Out	(2,700,000)		(2,684,096)		(2,684,096)
Ending Balance		5,752,385	5,048,708	5,752,385	5,048,708
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	7,605	9,310	7,605	9,767	7,847
Purchases		0	0	0	0
Settlements		(176)	(169)	(523)	(1,043)
Allowance for Losses		0	0	0	0
Realized and unrealized (losses)/gains included in Income		0	0	0	0
Unrealized gains/(losses) included in Other Comprehensive Income		172	2,553	62	3,185
Transfers Out			0		0
Ending Balance		9,306	9,989	9,306	9,989
USDA Securities | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,348	1,026	1,348	1,241	1,767
Purchases		0	0	0	0
Settlements		(198)	(44)	(414)	(479)
Allowance for Losses		0	0	0	0
Realized and unrealized (losses)/gains included in Income		14	(2)	15	14
Unrealized gains/(losses) included in Other Comprehensive Income		0	0	0	0
Transfers Out			0		0
Ending Balance		842	1,302	842	1,302
Guarantee and commitment obligations: | Level 3 | Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	4,331	5,559	4,331	5,831	4,467
Purchases		0	0	0	0
Settlements		(86)	(84)	(256)	(506)
Allowance for Losses		0	0	0	0
Realized and unrealized (losses)/gains included in Income		83	1,716	(19)	2,002
Unrealized gains/(losses) included in Other Comprehensive Income		0	0	0	0
Transfers Out			0		0
Ending Balance		5,556	5,963	5,556	5,963
Guarantee and commitment obligations: | Level 3 | Recurring | Guarantee Asset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 4,331	5,559	4,331	5,831	4,467
Purchases		0	0	0	0
Settlements		(86)	(84)	(256)	(506)
Allowance for Losses		0	0	0	0
Realized and unrealized (losses)/gains included in Income		83	1,716	(19)	2,002
Unrealized gains/(losses) included in Other Comprehensive Income		0	0	0	0
Transfers Out			0		0
Ending Balance		$ 5,556	$ 5,963	$ 5,556	$ 5,963