Farmer Mac Guaranteed Securities and USDA Guaranteed Securities - Narrative (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-Sale Continuous Unrealized Loss Position more than 12 months, Aggregate Losses	$ 12,452	$ 15,430
Institutional Credit [Member] | Farmer Mac Guaranteed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure [Abstract]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions In Loss Position Greater than Twelve Months	17
Available-for-Sale Continuous Unrealized Loss Position more than 12 months, Aggregate Losses	$ 15,200