Loans and Allowance for Losses and Concentrations of Credit Risk - Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for loan losses	$ (573,000)	$ (430,000)
Total Allowance for Losses	13,979,000	14,252,000	13,334,000	16,890,000
Provision for/(release of) losses	101,000	746,000
Eligible Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for loan losses	(573,000)	(430,000)
Allowance for Loan Losses - Charge-offs	29,000	3,814,000
Long-Term Standby Purchase Commitments and Farmer Mac Guaranteed Securities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for/(release of) losses	101,000	746,000
Financing Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Modifications, Pre-Modification Recorded Investment	600,000	200,000
Financing Receivable, Modifications, Post-Modification Recorded Investment	600,000	300,000
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	3
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		1,300,000
Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Allowance for Losses	7,715,000	6,971,000	7,292,000	9,661,000
Agriculture Storage and Processing [Member] | Eligible Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for Loan Losses - Charge-offs		$ 3,600,000