Off-Balance Sheet Guarantees and Long Term Standby Purchase Commitments - Off-Balance Sheet Guaranteed Securities (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Farmer Mac Guaranteed Securities [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Farmer Mac Guaranteed Securities [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Sep. 30, 2014 Farmer Mac Guaranteed Securities [Member] Farm & Ranch [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Farmer Mac Guaranteed Securities [Member] Farm & Ranch [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Sep. 30, 2014 Farmer Mac Guaranteed Securities [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Farmer Mac Guaranteed Securities [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Sep. 30, 2014 Farmer Mac Guaranteed Securities [Member] Institutional Credit [Member] Variable Interest Entity, Not Primary Beneficiary [Member]	Dec. 31, 2013 Farmer Mac Guaranteed Securities [Member] Institutional Credit [Member] Variable Interest Entity, Not Primary Beneficiary [Member]
Long-term Purchase Commitment [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted		$ 1,680,694	$ 1,766,982	$ 677,814	$ 765,751	$ 14,693	$ 20,222	$ 988,187	$ 981,009
Loans and Leases Receivable, Impaired, Loans Past Due Period, Minimum	90 days