Accounting Policies - Cash and Cash Equivalents and Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Non-cash activity:
Proceeds from sale of Farmer Mac Guaranteed Securities	$ 139,561	$ 49,487
Consolidation of Farm & Ranch Guaranteed Securities from off-balance sheet to loans held for investment in consolidated trusts and to debt securities of consolidated trusts held by third parties	135,913	49,487
Purchases of securities - traded, not yet settled	0	14,915
Issuance Costs on the retirement of Farmer Mac II LLC Preferred Stock	$ 0	$ 8,147