Farmer Mac Guaranteed Securities and USDA Guaranteed Securities - Schedule of Held-to-maturity Securities (Details) (Farmer Mac Guarantee [Member], Farmer Mac Guaranteed Securities [Member], USD $) In Thousands, unless otherwise specified	Jun. 30, 2014
Held-to-maturity Securities, Amortized Cost
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount	$ 501
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	1,655,953
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	1,656,454
Held-to-maturity Securities [Member]
Held-to-maturity Securities, Fair Value
Held-to-maturity Securities, Debt Maturities, Next Twelve Months, Fair Value	501
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	1,659,547
Held-to-maturity Securities, Fair Value	$ 1,660,048
Held to Maturity Securities Weighted Average Yield
Held-to-Maturity Securities, Debt Maturities, Next Twelve Months, Weighted-Average Yield	5.75%
Held-to-Maturity Securities, Debt Maturities, Year Two Through Five, Weighted-Average Yield	2.45%
Held-to-Maturity Securities, Debt Maturities, Weighted-Average Yield	2.45%