Accounting Policies - Cash and Cash Equivalents and Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Non-cash activity:
Proceeds from sale of Farmer Mac Guaranteed Securities			$ 457,369	$ 231,242
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			402,841	231,242
Purchases of securities - traded, not yet settled			25,000	15,000
Issuance Costs on the retirement of Farmer Mac II LLC Preferred Stock	$ 0	$ 0	0	8,147
Unsettled Class C Common Stock Repurchases			$ 0	$ 796