Fair Value Disclosures - Summary of Carrying Value and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial derivatives	$ 2,674	$ 23,182
Guarantee and commitment fees receivable:	38,748	38,871
Derivative Liability	6,979	32,509
Guarantee and commitment obligation	36,802	37,282
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	313,641	265,229
Loans	4,635,230	4,507,435
Financial derivatives	2,674	23,182
Debt securities of consolidated trusts held by third parties	1,212,792	1,142,704
Derivative Liability	32,054	58,152
Reported Value Measurement [Member] \| Investment Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	2,479,244	2,515,851
Reported Value Measurement [Member] \| Farmer Mac Guaranteed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	6,317,732	6,002,916
Reported Value Measurement [Member] \| USDA Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	2,044,424	2,029,613
Reported Value Measurement [Member] \| Long-Term Standby Purchase Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Guarantee and commitment fees receivable:	32,926	32,656
Guarantee and commitment obligation	32,089	31,796
Reported Value Measurement [Member] \| Farmer Mac Guaranteed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Guarantee and commitment fees receivable:	5,822	6,215
Guarantee and commitment obligation	4,713	5,486
Reported Value Measurement [Member] \| Due within one year [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable:	7,616,431	8,440,123
Reported Value Measurement [Member] \| Long-term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable:	6,300,750	5,222,977
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	313,641	265,229
Loans	4,663,885	4,481,019
Financial derivatives	2,674	23,182
Debt securities of consolidated trusts held by third parties	1,199,226	1,107,513
Derivative Liability	32,054	58,152
Estimate of Fair Value Measurement [Member] \| Investment Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	2,479,244	2,515,851
Estimate of Fair Value Measurement [Member] \| Farmer Mac Guaranteed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	6,321,194	6,006,694
Estimate of Fair Value Measurement [Member] \| USDA Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable Securities	1,978,216	1,934,023
Estimate of Fair Value Measurement [Member] \| Long-Term Standby Purchase Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Guarantee and commitment fees receivable:	34,137	34,720
Guarantee and commitment obligation	33,300	33,860
Estimate of Fair Value Measurement [Member] \| Farmer Mac Guaranteed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Guarantee and commitment fees receivable:	5,791	6,197
Guarantee and commitment obligation	4,682	5,467
Estimate of Fair Value Measurement [Member] \| Due within one year [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable:	7,613,484	8,439,515
Estimate of Fair Value Measurement [Member] \| Long-term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes payable:	$ 6,345,661	$ 5,260,497

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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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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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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