Financial Derivatives - Schedule of Net Income/(Expense) Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Investments and cash equivalents	$ 69,779	$ 11,200	$ 129,482	$ 16,916
Interest Income Farmer Mac Guaranteed Securities and USDA Securities	144,761	51,616	281,298	94,536
Interest Income Loans	129,292	76,632	248,324	143,879
Total interest expense	(265,155)	(75,534)	(501,369)	(125,879)
Gains on financial derivatives	1,693	3,791	2,092	20,779
Total	80,370	67,705	159,827	150,231
Interest expense on interest rate swaps	5,871	7,675	11,226	29,080
Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(102,251)	(194,709)	(47,269)	(330,874)
(Losses)/gains on fair value hedging relationships	(4,901)	549	(5,006)	6,578
Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(15)	(27)	(29)
Interest settlements reclassified from AOCI into net income on derivatives	5,091	(1,155)	9,482	(3,166)
Recognized on hedged items	(7,848)	(1,821)	(15,038)	(2,608)
Expense recognized on cash flow hedges	(2,771)	(2,991)	(5,583)	(5,803)
Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(11,084)	27,876	(17,919)	56,864
Premium/discount amortization recognized on hedged items	(205)	(827)	(628)	(1,681)
No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	1,693	3,791	2,092	20,779
Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(31,969)	(22,969)	(4,541)	(55,694)
(Losses)/gains on fair value hedging relationships	(1,145)	1,169	(870)	1,868
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	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 | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	7,898	3,219	14,859	5,816
Premium/discount amortization recognized on hedged items	508	(343)	776	(757)
Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	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	(101,921)	(149,266)	(8,625)	(359,914)
(Losses)/gains on fair value hedging relationships	(1,059)	(1,084)	(1,555)	2,119
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	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 | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	45,722	34,431	87,693	66,359
Premium/discount amortization recognized on hedged items	0	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	0
Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(49,381)	(107,347)	7,576	(236,953)
(Losses)/gains on fair value hedging relationships	(2,619)	2,072	(2,343)	4,398
Interest Income Loans | 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 | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	15,848	13,669	31,056	26,288
Premium/discount amortization recognized on hedged items	0	0	0	0
Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	81,020	84,873	(41,679)	321,687
(Losses)/gains on fair value hedging relationships	(78)	(1,608)	(238)	(1,807)
Total Interest Expense | Cash flow hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Premium/discount amortization recognized on hedged items	(14)	(15)	(27)	(29)
Interest settlements reclassified from AOCI into net income on derivatives	5,091	(1,155)	9,482	(3,166)
Recognized on hedged items	(7,848)	(1,821)	(15,038)	(2,608)
Expense recognized on cash flow hedges	(2,771)	(2,991)	(5,583)	(5,803)
Total Interest Expense | Designated as hedge | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	(80,552)	(23,443)	(151,527)	(41,599)
Premium/discount amortization recognized on hedged items	(713)	(484)	(1,404)	(924)
Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Gains on financial derivatives | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on hedged items	0	0	0	0
(Losses)/gains on fair value hedging relationships	0	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	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
Gains 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
Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	1,693	3,791	2,092	20,779
Interest Rate Swap | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(29,023)	(16,512)	(57,852)	(32,386)
Income/(expense) related to interest settlements on fair value hedging relationships	(40,312)	10,537	(76,399)	22,797
Recognized on derivatives	97,350	195,258	42,263	337,452
Interest Rate Swap | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	2,458	4,284	2,490	5,901
Interest expense on interest rate swaps	(1,568)	(1,955)	(3,193)	(2,883)
Interest Rate Swap | Interest Income Investments and Cash Equivalents | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	8,452	(1,008)	15,001	(2,492)
Income/(expense) related to interest settlements on fair value hedging relationships	16,858	1,868	30,636	2,567
Recognized on derivatives	30,824	24,138	3,671	57,562
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	0
Interest expense on interest rate swaps	0	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	34,999	(15,693)	63,909	(37,337)
Income/(expense) related to interest settlements on fair value hedging relationships	80,721	18,738	151,602	29,022
Recognized on derivatives	100,862	148,182	7,070	362,033
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	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Interest Income Loans | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	15,754	(4,459)	28,933	(11,405)
Income/(expense) related to interest settlements on fair value hedging relationships	31,602	9,210	59,989	14,883
Recognized on derivatives	46,762	109,419	(9,919)	241,351
Interest Rate Swap | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	0	0	0
Interest Rate Swap | Total Interest Expense | Fair value hedges:
Derivative Instruments, Gain (Loss) [Line Items]
Recognized on derivatives	(88,228)	4,648	(165,695)	18,848
Income/(expense) related to interest settlements on fair value hedging relationships	(169,493)	(19,279)	(318,626)	(23,675)
Recognized on derivatives	(81,098)	(86,481)	41,441	(323,494)
Interest Rate Swap | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Interest expense on interest rate swaps	0	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	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 | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	2,458	4,284	2,490	5,901
Interest expense on interest rate swaps	(1,568)	(1,955)	(3,193)	(2,883)
Treasury futures | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	803	1,462	2,795	17,761
Treasury futures | Interest Income Investments and Cash Equivalents | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
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]
Gains on financial derivatives	0	0	0	0
Treasury futures | Interest Income Loans | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Treasury futures | Total Interest Expense | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	0	0	0	0
Treasury futures | Gains on financial derivatives | No hedge designation
Derivative Instruments, Gain (Loss) [Line Items]
Gains on financial derivatives	$ 803	$ 1,462	$ 2,795	$ 17,761