Equity - Non-controlling interest (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 25, 2010	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Class of Stock [Line Items]
Preferred Stock Redemption Premium		$ 0	$ 0	$ 8,147	$ 0
Farmer Mac II LLC [Member]
Class of Stock [Line Items]
Sale of Stock, Consideration Received on Transaction	$ 250,000
Farmer Mac II LLC [Member] | Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share		$ 1,000		$ 1,000
Farmer Mac II LLC [Member] | Private Placement [Member] | Preferred Stock [Member]
Class of Stock [Line Items]
Sale of Stock, Number of Shares Issued in Transaction	250,000
Non-controlling Interest - Preferred Stock [Member]
Class of Stock [Line Items]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests			$ 6,000	$ 235,853	$ 6,000