FAIR VALUE DISCLOSURES - Schedule of Unobservable Input Reconciliation (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 5,539,404	$ 5,557,392	$ 7,630,720
Purchases	2,013,475	677,400	2,084,650
Sales	(19,537)
Settlements	(924,209)	(667,518)	(1,563,310)
Allowance for Losses	133	81	236
Realized and unrealized (losses)/gains included in Income	$ 130,232	(49,833)	91,583
Fair Value Recurring Basis Unobservable Input Reconciliation Asset Gain Loss Statement Of Income Extensible List Not Disclosed Flag	Realized andunrealized (losses)/gains included in Income
Unrealized gains/(losses) included in other comprehensive income	$ 4,519	$ 21,882	$ (2,391)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Net unrealized gains on available-for-sale securities	Net unrealized gains on available-for-sale securities	Net unrealized gains on available-for-sale securities
Transfers Out			$ (2,684,096)
Ending Balance	$ 6,744,017	$ 5,539,404	5,557,392
Available-for-sale securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,534,022	5,551,561	7,626,253
Purchases	2,013,475	677,400	2,084,650
Sales	(19,537)
Settlements	(923,868)	(667,175)	(1,562,720)
Allowance for Losses	133	81	236
Realized and unrealized (losses)/gains included in Income	130,376	(49,727)	89,629
Unrealized gains/(losses) included in other comprehensive income	4,519	21,882	(2,391)
Transfers Out			(2,684,096)
Ending Balance	6,739,120	5,534,022	5,551,561
Auction-rate certificates backed by Government guaranteed student loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	19,476	19,082	19,027
Purchases	0	0	0
Sales	(19,537)
Settlements	0	0	0
Allowance for Losses	27	0	6
Realized and unrealized (losses)/gains included in Income	(163)	0	0
Unrealized gains/(losses) included in other comprehensive income	197	394	49
Transfers Out			0
Ending Balance	0	19,476	19,082
AgVantage
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,505,531	5,522,712	7,599,379
Purchases	2,013,475	677,400	2,084,650
Sales	0
Settlements	(923,198)	(666,476)	(1,561,507)
Allowance for Losses	106	81	230
Realized and unrealized (losses)/gains included in Income	130,539	(49,727)	89,629
Unrealized gains/(losses) included in other comprehensive income	4,464	21,541	(5,573)
Transfers Out			(2,684,096)
Ending Balance	6,730,917	5,505,531	5,522,712
Interest-Only Farmer Mac Guaranteed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9,015	9,767	7,847
Purchases	0	0	0
Sales	0
Settlements	(670)	(699)	(1,213)
Allowance for Losses	0	0	0
Realized and unrealized (losses)/gains included in Income	0	0	0
Unrealized gains/(losses) included in other comprehensive income	(142)	(53)	3,133
Transfers Out			0
Ending Balance	8,203	9,015	9,767
Other Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	5,382	5,831	4,467
Purchases	0	0	0
Sales	0
Settlements	(341)	(343)	(590)
Allowance for Losses	0	0	0
Realized and unrealized (losses)/gains included in Income	(144)	(106)	1,954
Unrealized gains/(losses) included in other comprehensive income	0	0	0
Transfers Out			0
Ending Balance	$ 4,897	$ 5,382	$ 5,831