Off-Balance Sheet Guarantees and Long Term Standby Purchase Commitments - Cash Flows from Off-balance sheet Guaranteed Securities (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Guarantor Obligations [Line Items]
Proceeds from sale of Farmer Mac Guaranteed Securities	$ 175,754,000	$ 150,417,000	$ 38,063,000
Proceeds from Fees Received	4,612,000us-gaap_ProceedsFromFeesReceived	5,182,000us-gaap_ProceedsFromFeesReceived	5,197,000us-gaap_ProceedsFromFeesReceived
Payments to Acquire Loans and Leases Held-for-investment	0	6,667,000	8,933,000
Farmer Mac Guaranteed Securities [Member]
Guarantor Obligations [Line Items]
Weighted average remaining maturity, Loans underlying guarantees not held by transferor	12 years 0 months 0 days	12 years 9 months 18 days
Farmer Mac Guaranteed Securities [Member] \| Variable Interest Entity, Not Primary Beneficiary [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 11,100,000	$ 13,400,000
Institutional Credit [Member] \| Farmer Mac Guaranteed Securities [Member]
Guarantor Obligations [Line Items]
Weighted average remaining maturity, Loans underlying guarantees not held by transferor	2 years 5 months 5 days	3 years 4 months 20 days

Weighted average remaining maturity, Loans underlying guarantees not held by transferor

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

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- Definition

The cash outflow from (a) purchases of loans held-for-investment, (b) purchases of leases held-for-investment, and (c) both.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

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- Definition

Cash received for fees during the current period. This element excludes cash proceeds from license fees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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- Definition

The cash inflow associated with the sale of other investments not otherwise defined in the taxonomy.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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