Financial Derivatives - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 82,659	$ 18,660	$ 42,144
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	283,769	164,723	232,951
Interest Income Loans	350,420	242,582	233,699
Total interest expense	(445,908)	(204,014)	(312,946)
Gains on financial derivatives	22,631	324	1,744
Total	293,571	222,275	155,448
Noninterest Income	38,688	23,066	18,043
Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(514,121)	(179,407)	230,330
Gains/(losses) on fair value hedging relationships	5,802	(340)	(3,924)
Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(57)	(37)	(13)
Interest settlements reclassified from AOCI into net income on derivatives	1,213	(7,399)	(5,570)
Recognized on hedged items	(12,847)	(2,657)	(4,553)
Expense recognized on cash flow hedges	(11,691)	(10,093)	(10,136)
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	82,743	117,046	115,733
Premium/discount amortization recognized on hedged items	(2,870)	(1,118)	(745)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	22,631	324	1,744
Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(105,889)	(1,218)	202,624
Gains/(losses) on fair value hedging relationships	(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
Interest Income Investments and Cash Equivalents | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	16,199	1,792	126,170
Premium/discount amortization recognized on hedged items	(754)	0	0
Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0
Interest Income Farmer Mac Guaranteed Securities and USDA Securities | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(553,393)	(176,304)
Gains/(losses) on fair value hedging relationships	137	1,948	1,603
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
Interest settlements reclassified from AOCI into net income on derivatives	0	0
Recognized on hedged items	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	142,809	119,896
Premium/discount amortization recognized on hedged items	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	(341,162)	(97,502)	73,426
Gains/(losses) on fair value hedging relationships	9,954	(43)	(3,139)
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	56,141	46,842	40,793
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	486,323	95,617	(45,720)
Gains/(losses) on fair value hedging relationships	(3,122)	(2,715)	(2,388)
Total Interest Expense | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(57)	(37)	(13)
Interest settlements reclassified from AOCI into net income on derivatives	1,213	(7,399)	(5,570)
Recognized on hedged items	(12,847)	(2,657)	(4,553)
Expense recognized on cash flow hedges	(11,691)	(10,093)	(10,136)
Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(132,406)	(51,484)	(51,230)
Premium/discount amortization recognized on hedged items	(2,116)	(1,118)	(745)
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
Gains/(losses) 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	22,631	324	1,744
Interest Rate Swap | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(79,201)	(70,880)	(52,805)
Income/(expense) related to interest settlements on fair value hedging relationships	672	45,048	62,183
Recognized on derivatives	519,923	179,067	(234,254)
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	13,012	(2,144)	(2,214)
Noninterest Income	(7,619)	3,259	5,808
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	2,727	(1,002)	(60,056)
Income/(expense) related to interest settlements on fair value hedging relationships	18,172	790
Recognized on derivatives	104,722	1,688	(201,021)
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
Noninterest Income	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	(19,486)	(85,302)
Income/(expense) related to interest settlements on fair value hedging relationships	123,323	34,594	66,114
Recognized on derivatives	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
Noninterest Income	0	0
Interest Rate Swap | Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(501)	(27,167)	(19,135)
Income/(expense) related to interest settlements on fair value hedging relationships	55,640	19,675	21,658
Recognized on derivatives	351,116	97,459	(76,565)
Interest Rate Swap | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Noninterest Income	0	0	0
Interest Rate Swap | Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(61,941)	42,591	26,386
Income/(expense) related to interest settlements on fair value hedging relationships	(196,463)	(10,011)	(25,589)
Recognized on derivatives	(489,445)	(98,332)	43,332
Interest Rate Swap | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0
Noninterest Income	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	13,012	(2,144)	(2,214)
Noninterest Income	(7,619)	3,259	5,808
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	17,238	(791)	(1,850)
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
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	$ 17,238	$ (791)	$ (1,850)