Equity - Non-Controlling Interest (Details) - Farmer Mac II LLC [Member] - USD ($) $ / shares in Units, $ in Millions	Jan. 25, 2010	Dec. 31, 2014
Class of Stock [Line Items]
Sale of Stock, Consideration Received on Transaction	$ 250.0
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share		$ 1,000
Private Placement [Member] | Preferred Stock [Member]
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	250,000