FINANCIAL DERIVATIVES - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 84,538	$ 69,779	$ 169,462	$ 129,482
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	166,063
Interest Income Loans	153,105	129,292	297,685	248,324
Total interest expense	(316,366)	(265,155)	(626,315)	(501,369)
(Losses)/gains on financial derivatives	(1,799)	1,693	280	2,092
Total	85,541
Interest expense on interest rate swaps	2,526	5,871	9,840	11,226
Designated as hedge
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents		69,779	169,462	129,482
Interest Income Farmer Mac Guaranteed Securities and USDA Securities		144,761	332,876	281,298
Interest Income Loans		129,292	297,685	248,324
Total interest expense		(265,155)	(626,315)	(501,369)
(Losses)/gains on financial derivatives		1,693	280	2,092
Total		80,370	173,988	159,827
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(27,625)	(11,084)	(55,808)	(17,919)
Premium/discount amortization recognized on hedged items	(234)	(205)	(535)	(628)
Recognized on hedged items	(51,842)	(102,251)	(151,678)	(47,269)
Gains/(losses) on fair value hedging relationships	2,604	(4,901)	5,606	(5,006)
Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(14)	(27)	(27)
Interest settlements reclassified from AOCI into net income on derivatives	5,393	5,091	10,824	9,482
Recognized on hedged items	(8,014)	(7,848)	(16,105)	(15,038)
Expense recognized on cash flow hedges	(2,635)	(2,771)	(5,308)	(5,583)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,799)	1,693	280	2,092
Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	10,309	7,898	20,257	14,859
Premium/discount amortization recognized on hedged items	487	508	933	776
Recognized on hedged items	(3,361)	(31,969)	(30,882)	(4,541)
Gains/(losses) on fair value hedging relationships	99	(1,145)	368	(870)
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	52,651	45,722	104,356	87,693
Premium/discount amortization recognized on hedged items	0	0	0	0
Recognized on hedged items	(6,508)	(101,921)	(87,251)	(8,625)
Gains/(losses) on fair value hedging relationships	418	(1,059)	1,261	(1,555)
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	16,705	15,848	33,302	31,056
Premium/discount amortization recognized on hedged items	0	0	0	0
Recognized on hedged items	(12,112)	(49,381)	(59,173)	7,576
Gains/(losses) on fair value hedging relationships	1,076	(2,619)	2,195	(2,343)
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	(107,290)	(80,552)	(213,723)	(151,527)
Premium/discount amortization recognized on hedged items	(721)	(713)	(1,468)	(1,404)
Recognized on hedged items	(29,861)	81,020	25,628	(41,679)
Gains/(losses) on fair value hedging relationships	1,011	(78)	1,782	(238)
Total Interest Expense | Designated as hedge | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(14)	(27)	(27)
Interest settlements reclassified from AOCI into net income on derivatives	5,393	5,091	10,824	9,482
Recognized on hedged items	(8,014)	(7,848)	(16,105)	(15,038)
Expense recognized on cash flow hedges	(2,635)	(2,771)	(5,308)	(5,583)
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	(1,799)	1,693	280	2,092
Interest Rate Swap | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(9,290)	(29,023)	(24,362)	(57,852)
Income/(expense) related to interest settlements on fair value hedging relationships	(37,149)	(40,312)	(80,705)	(76,399)
Recognized on derivatives	54,446	97,350	157,284	42,263
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(26)	2,458	729	2,490
Interest expense on interest rate swaps	(486)	(1,568)	(521)	(3,193)
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	10,408	8,452	20,705	15,001
Income/(expense) related to interest settlements on fair value hedging relationships	21,204	16,858	41,895	30,636
Recognized on derivatives	3,460	30,824	31,250	3,671
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	39,134	34,999	79,467	63,909
Income/(expense) related to interest settlements on fair value hedging relationships	91,785	80,721	183,823	151,602
Recognized on derivatives	6,926	100,862	88,512	7,070
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	17,827	15,754	35,676	28,933
Income/(expense) related to interest settlements on fair value hedging relationships	34,532	31,602	68,978	59,989
Recognized on derivatives	13,188	46,762	61,368	(9,919)
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	(76,659)	(88,228)	(160,210)	(165,695)
Income/(expense) related to interest settlements on fair value hedging relationships	(184,670)	(169,493)	(375,401)	(318,626)
Recognized on derivatives	30,872	(81,098)	(23,846)	41,441
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	(26)	2,458	729	2,490
Interest expense on interest rate swaps	(486)	(1,568)	(521)	(3,193)
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
(Losses)/gains on financial derivatives	(1,287)	803	72	2,795
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	$ (1,287)	$ 803	$ 72	$ 2,795