FINANCIAL DERIVATIVES - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 287,144	$ 82,659	$ 18,660
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	590,250	283,769	164,723
Interest Income Loans	514,894	350,420	242,582
Total interest expense	(1,064,741)	(445,908)	(204,014)
Gains on financial derivatives	2,882	22,631	324
Total	330,429	293,571	222,275
Interest expense on interest rate swaps	23,511	38,688	23,066
Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(151,073)	(514,121)	(179,407)
(Losses)/gains on fair value hedging relationships	(5,394)	5,802	(340)
Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(55)	(57)	(37)
Interest settlements reclassified from AOCI into net income on derivatives	20,643	1,213	(7,399)
Recognized on hedged items	(31,610)	(12,847)	(2,657)
Expense recognized on cash flow hedges	(11,022)	(11,691)	(10,093)
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(61,506)	82,743	117,046
Premium/discount amortization recognized on hedged items	(1,005)	(2,870)	(1,118)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	2,882	22,631	324
Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	18,472	(105,889)	(1,218)
(Losses)/gains on fair value hedging relationships	(973)	(1,167)	470
Interest Income Investments and Cash Equivalents | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0
Recognized on hedged items	0	0	0
Expense recognized on cash flow hedges	0	0	0
Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	33,488	16,199	1,792
Premium/discount amortization recognized on hedged items	1,860	(754)	0
Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	89,437	(553,393)	(176,304)
(Losses)/gains on fair value hedging relationships	(1,714)	137	1,948
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0
Recognized on hedged items	0	0	0
Expense recognized on cash flow hedges	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	183,396	142,809	119,896
Premium/discount amortization recognized on hedged items	0	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	21,686	(341,162)	(97,502)
(Losses)/gains on fair value hedging relationships	(1,842)	9,954	(43)
Interest Income Loans | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0
Recognized on hedged items	0	0	0
Expense recognized on cash flow hedges	0	0	0
Interest Income Loans | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	63,133	56,141	46,842
Premium/discount amortization recognized on hedged items	0	0	0
Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(280,668)	486,323	95,617
(Losses)/gains on fair value hedging relationships	(865)	(3,122)	(2,715)
Total Interest Expense | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(55)	(57)	(37)
Interest settlements reclassified from AOCI into net income on derivatives	20,643	1,213	(7,399)
Recognized on hedged items	(31,610)	(12,847)	(2,657)
Expense recognized on cash flow hedges	(11,022)	(11,691)	(10,093)
Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(341,523)	(132,406)	(51,484)
Premium/discount amortization recognized on hedged items	(2,865)	(2,116)	(1,118)
Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Gains on financial derivatives | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0
(Losses)/gains on fair value hedging relationships	0	0	0
Gains on financial derivatives | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	0	0	0
Interest settlements reclassified from AOCI into net income on derivatives	0	0	0
Recognized on hedged items	0	0	0
Expense recognized on cash flow hedges	0	0	0
Gains on financial derivatives | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0
Premium/discount amortization recognized on hedged items	0	0	0
Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	2,882	22,631	324
Interest Rate Swap | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(99,800)	(79,201)	(70,880)
Income/(expense) related to interest settlements on fair value hedging relationships	(162,311)	672	45,048
Recognized on derivatives	145,679	519,923	179,067
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	4,395	13,012	(2,144)
Interest expense on interest rate swaps	(4,845)	(7,619)	3,259
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	35,377	2,727	(1,002)
Income/(expense) related to interest settlements on fair value hedging relationships	70,725	18,172	790
Recognized on derivatives	(19,445)	104,722	1,688
Interest Rate Swap | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest expense on interest rate swaps	0	0	0
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	146,027	(19,486)	(85,302)
Income/(expense) related to interest settlements on fair value hedging relationships	329,423	123,323	34,594
Recognized on derivatives	(91,151)	553,530	178,252
Interest Rate Swap | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest expense on interest rate swaps	0	0	0
Interest Rate Swap | Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	64,648	(501)	(27,167)
Income/(expense) related to interest settlements on fair value hedging relationships	127,781	55,640	19,675
Recognized on derivatives	(23,528)	351,116	97,459
Interest Rate Swap | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest expense on interest rate swaps	0	0	0
Interest Rate Swap | Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(345,852)	(61,941)	42,591
Income/(expense) related to interest settlements on fair value hedging relationships	(690,240)	(196,463)	(10,011)
Recognized on derivatives	279,803	(489,445)	(98,332)
Interest Rate Swap | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Interest expense on interest rate swaps	0	0	0
Interest Rate Swap | Gains on financial derivatives | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	0	0	0
Income/(expense) related to interest settlements on fair value hedging relationships	0	0	0
Recognized on derivatives	0	0	0
Interest Rate Swap | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	4,395	13,012	(2,144)
Interest expense on interest rate swaps	(4,845)	(7,619)	3,259
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	3,332	17,238	(791)
Treasury futures | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Treasury futures | Interest Income Farmer Mac Guaranteed Securities and USDA Securities | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Treasury futures | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Treasury futures | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Treasury futures | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	$ 3,332	$ 17,238	$ (791)