FINANCIAL DERIVATIVES - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 88,879	$ 79,947	$ 258,341	$ 209,429
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	156,602
Interest Income Loans	162,247	140,513	459,932	388,837
Total interest expense	(320,937)	(294,168)	(947,252)	(795,537)
(Losses)/gains on financial derivatives	(1,934)	2,671	(1,654)	4,763
Total	84,857
Interest expense on interest rate swaps	3,669	9,505	13,509	20,731
Designated as hedge
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents		79,947	258,341	209,429
Interest Income Farmer Mac Guaranteed Securities and USDA Securities		161,351	489,478	442,649
Interest Income Loans		140,513	459,932	388,837
Total interest expense		(294,168)	(947,252)	(795,537)
(Losses)/gains on financial derivatives		2,671	(1,654)	4,763
Total		90,314	258,845	250,141
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(22,621)	(20,127)	(78,426)	(38,049)
Premium/discount amortization recognized on hedged items	(65)	(109)	(601)	(738)
Recognized on hedged items	137,139	(265,777)	(14,540)	(313,047)
Gains/(losses) on fair value hedging relationships	205	3,210	5,811	(1,796)
Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(14)	(42)	(41)
Interest settlements reclassified from AOCI into net income on derivatives	5,338	5,569	16,162	15,051
Recognized on hedged items	(7,918)	(8,287)	(24,023)	(23,325)
Expense recognized on cash flow hedges	(2,594)	(2,732)	(7,903)	(8,315)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,934)	2,671	(1,654)	4,763
Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	11,476	9,006	31,734	23,865
Premium/discount amortization recognized on hedged items	623	623	1,555	1,399
Recognized on hedged items	60,915	(41,944)	30,032	(46,485)
Gains/(losses) on fair value hedging relationships	116	107	483	(763)
Interest Income Investments and Cash Equivalents | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	54,513	46,303	158,869	133,995
Premium/discount amortization recognized on hedged items	0	0	0	0
Recognized on hedged items	189,141	(107,965)	101,890	(116,591)
Gains/(losses) on fair value hedging relationships	(557)	2,231	704	676
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest Income Loans | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	17,544	16,089	50,847	47,144
Premium/discount amortization recognized on hedged items	0	0	0	0
Recognized on hedged items	98,015	(105,403)	38,842	(97,827)
Gains/(losses) on fair value hedging relationships	(449)	1,862	1,746	(481)
Interest Income Loans | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(106,154)	(91,525)	(319,876)	(243,053)
Premium/discount amortization recognized on hedged items	(688)	(732)	(2,156)	(2,137)
Recognized on hedged items	(210,932)	(10,465)	(185,304)	(52,144)
Gains/(losses) on fair value hedging relationships	1,095	(990)	2,878	(1,228)
Total Interest Expense | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(14)	(42)	(41)
Interest settlements reclassified from AOCI into net income on derivatives	5,338	5,569	16,162	15,051
Recognized on hedged items	(7,918)	(8,287)	(24,023)	(23,325)
Expense recognized on cash flow hedges	(2,594)	(2,732)	(7,903)	(8,315)
Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Losses on financial derivatives | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0	0
Premium/discount amortization recognized on hedged items	0	0	0	0
Recognized on hedged items	0	0	0	0
Gains/(losses) on fair value hedging relationships	0	0	0	0
Losses on financial derivatives | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0	0
Recognized on hedged items	0	0	0	0
Expense recognized on cash flow hedges	0	0	0	0
Losses on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,934)	2,671	(1,654)	4,763
Interest Rate Swap | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(1,654)	(24,907)	(26,016)	(82,758)
Income/(expense) related to interest settlements on fair value hedging relationships	(24,340)	(45,143)	(105,043)	(121,545)
Recognized on derivatives	(136,934)	268,987	20,351	311,251
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,310)	2,772	(581)	5,263
Interest expense on interest rate swaps	(858)	(805)	(1,379)	(3,999)
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	10,774	9,950	31,479	24,952
Income/(expense) related to interest settlements on fair value hedging relationships	22,873	19,579	64,768	50,216
Recognized on derivatives	(60,799)	42,051	(29,549)	45,722
Interest Rate Swap | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	39,127	40,114	118,593	104,023
Income/(expense) related to interest settlements on fair value hedging relationships	93,640	86,417	277,462	238,018
Recognized on derivatives	(189,698)	110,196	(101,186)	117,267
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Interest Income Loans | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	17,878	17,692	53,554	46,625
Income/(expense) related to interest settlements on fair value hedging relationships	35,422	33,781	104,401	93,769
Recognized on derivatives	(98,464)	107,265	(37,096)	97,346
Interest Rate Swap | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(69,433)	(92,663)	(229,642)	(258,358)
Income/(expense) related to interest settlements on fair value hedging relationships	(176,275)	(184,920)	(551,674)	(503,548)
Recognized on derivatives	212,027	9,475	188,182	50,916
Interest Rate Swap | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Losses on financial derivatives | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	0	0	0	0
Income/(expense) related to interest settlements on fair value hedging relationships	0	0	0	0
Recognized on derivatives	0	0	0	0
Interest Rate Swap | Losses on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,310)	2,772	(581)	5,263
Interest expense on interest rate swaps	(858)	(805)	(1,379)	(3,999)
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	234	704	306	3,499
Treasury futures | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Treasury futures | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Treasury futures | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Treasury futures | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	0	0	0	0
Treasury futures | Losses on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	$ 234	$ 704	$ 306	$ 3,499