Fair Value Disclosures - Summary of Carrying Value and Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial derivatives	$ 12,237	$ 7,834
Guarantee and commitment fees receivable	36,664	38,442
Financial derivatives	188,289	105,087
Guarantee and commitment obligation	35,140	36,700
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	910,592	604,381
Loans	8,450,522	7,317,091
Financial derivatives	12,837	10,519
Guarantee and commitment fees receivable	34,801	36,732
Notes payable	21,893,043	19,234,079
Debt securities of consolidated trusts held by third parties	1,337,741	1,663,177
Financial derivatives	37,357	27,042
Guarantee and commitment obligation	33,278	34,990
Fair Value \| Investment securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	3,578,375	3,005,828
Fair Value \| Farmer Mac Guaranteed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	8,739,103	8,606,451
Fair Value \| USDA Securities:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	2,522,001	2,294,671
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	910,592	604,381
Loans	8,105,647	6,981,440
Financial derivatives	12,837	10,519
Guarantee and commitment fees receivable	36,664	38,442
Notes payable	21,589,285	19,098,648
Debt securities of consolidated trusts held by third parties	1,292,416	1,616,504
Financial derivatives	37,357	27,042
Guarantee and commitment obligation	35,140	36,700
Carrying Amount \| Investment securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	3,577,222	3,004,875
Carrying Amount \| Farmer Mac Guaranteed Securities
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	8,712,208	8,590,476
Carrying Amount \| USDA Securities:
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable securities	$ 2,417,678	$ 2,241,073

Marketable Securities, Fair Value Disclosure

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Variable Interest Entity, Consolidated, Fair Value Disclosure, Liabilities

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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The carrying amount of the contractual right to receive fees, as compensation in exchange for providing a guarantee to a third party, over life of the guarantee.

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This item represents a non-contingent liability for the fair value of an obligation to stand ready to perform over the term of a guaranty issued in the event that specified triggering events or conditions occur.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of notes payable.

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