Accounting Policies - Cash and Cash Equivalents and Statements of Cash Flows (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash paid during the period for: [Abstract]
Interest	$ 36,535,000	$ 33,068,000
Income taxes	0	0
Non-cash activity:
Real estate owned acquired through loan liquidation	0	1,034,000
Loans acquired and securitized as Farmer Mac Guaranteed Securities	62,751,000	25,042,000
Purchases of investment securities traded, not yet settled	0	325,000,000
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	62,751,000	25,042,000
Transfers of loans held for sale to loans held for investment	0	673,991,000
Transfer of Farmer Mac Guaranteed Securities - Available-for-sale to Held-to-maturity	$ 1,589,775,000	$ 0
Maximum [Member]
Supplemental Cash and Non-cash Transactions [Line Items]
Cash equivalent maturity period	3 months