INVESTMENT SECURITIES - Schedule of Farmer Mac Investment Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
AFS Securities
Amortized Cost	$ 15,557,363	$ 13,813,551
AFS investment securities	14,885,573	13,580,285
HTM:
Amortized Cost	4,475,876	3,954,223
Total AFS Investment Securities
AFS Securities
Amortized Cost	15,557,363	13,813,551
Allowance for losses	(73)	(130)
Unrealized Gains	2,563	71,380
Unrealized Losses	(674,280)	(304,516)
AFS investment securities	14,885,573	13,580,285
HTM:
Amortized Cost	4,475,968	3,954,300
Allowance for losses	(92)	(77)
Unrealized Gains	15,443	22,576
Unrealized Losses	(319,712)	(182,847)
Total	4,171,607	3,793,952
Available-for-sale, accrued interest excluded	109,900	91,300
Held-to-maturity, accrued interest excluded	53,500	56,700
Government/GSE guaranteed MBS
AFS Securities
Amortized Cost	5,969,800	5,351,174
Allowance for losses	0	0
Unrealized Gains	1,903	35,078
Unrealized Losses	(209,687)	(89,234)
AFS investment securities	5,762,016	5,297,018
HTM:
Amortized Cost		8,657
Allowance for losses		0
Unrealized Gains		281
Unrealized Losses		0
Total		8,938
U.S. Treasuries
AFS Securities
Amortized Cost	1,580,562	1,537,112
Allowance for losses	0	0
Unrealized Gains	15	7,083
Unrealized Losses	(19,486)	(48)
AFS investment securities	1,561,091	1,544,147
ABS
AFS Securities
Amortized Cost	65,316
Allowance for losses	0
Unrealized Gains	0
Unrealized Losses	(4,290)
AFS investment securities	61,026
AgVantage
AFS Securities
Amortized Cost	7,934,084	6,917,225
Allowance for losses	(73)	(130)
Unrealized Gains	403	29,056
Unrealized Losses	(440,817)	(215,234)
AFS investment securities	7,493,597	6,730,917
HTM:
Amortized Cost	1,903,385	1,486,284
Allowance for losses	(92)	(77)
Unrealized Gains	14,978	16,444
Unrealized Losses	(12,903)	(3,731)
Total	1,905,368	1,498,920
Interest-Only Farmer Mac Guaranteed Securities
AFS Securities
Amortized Cost	7,601	8,040
Allowance for losses	0	0
Unrealized Gains	242	163
Unrealized Losses	0	0
AFS investment securities	7,843	8,203
USDA Securities
HTM:
Amortized Cost	2,572,583	2,459,359
Allowance for losses	0	0
Unrealized Gains	465	5,851
Unrealized Losses	(306,809)	(179,116)
Total	$ 2,266,239	$ 2,286,094

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