Loans and Allowance for Losses and Concentrations of Credit Risk - Impaired Financing Receivables (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	$ 25,077			$ 24,951
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	25,257			24,733
Impaired Financing Receivable, with Related Allowance, Recorded Investment	68,163	[1]		72,116	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	66,820			70,308
Impaired Financing Receivable, Related Allowance	(2,692)			(2,696)
Impaired Financing Receivable, Recorded Investment	93,240			97,067
Impaired Financing Receivable, Unpaid Principal Balance	92,077			95,041
Financing Receivable, Recorded Investment, Nonaccrual Status	37,507	[3]		37,228	[4]
Impaired Financing Receivable, Average Recorded Investment	95,154		113,868
Impaired Financing Receivable, Interest Income, Accrual Method	562		1,064
Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	6,989			6,956
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	6,875			6,825
Impaired Financing Receivable, with Related Allowance, Recorded Investment	16,902	[1]		16,697	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	16,295			16,284
Impaired Financing Receivable, Related Allowance	(446)			(406)
Impaired Financing Receivable, Recorded Investment	23,891			23,653
Impaired Financing Receivable, Unpaid Principal Balance	23,170			23,109
Financing Receivable, Recorded Investment, Nonaccrual Status	10,926	[3]		10,812	[4]
Impaired Financing Receivable, Average Recorded Investment	23,772		31,830
Impaired Financing Receivable, Interest Income, Accrual Method	170		342
Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	9,913			9,880
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	10,010			9,877
Impaired Financing Receivable, with Related Allowance, Recorded Investment	34,077	[1]		36,146	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	33,229			34,978
Impaired Financing Receivable, Related Allowance	(1,675)			(1,702)
Impaired Financing Receivable, Recorded Investment	43,990			46,026
Impaired Financing Receivable, Unpaid Principal Balance	43,239			44,855
Financing Receivable, Recorded Investment, Nonaccrual Status	15,198	[3]		15,237	[4]
Impaired Financing Receivable, Average Recorded Investment	45,008		46,743
Impaired Financing Receivable, Interest Income, Accrual Method	194		374
Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	6,733			6,671
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	6,914			6,588
Impaired Financing Receivable, with Related Allowance, Recorded Investment	6,548	[1]		7,600	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	6,548			7,455
Impaired Financing Receivable, Related Allowance	(179)			(193)
Impaired Financing Receivable, Recorded Investment	13,281			14,271
Impaired Financing Receivable, Unpaid Principal Balance	13,462			14,043
Financing Receivable, Recorded Investment, Nonaccrual Status	5,280	[3]		5,344	[4]
Impaired Financing Receivable, Average Recorded Investment	13,776		17,906
Impaired Financing Receivable, Interest Income, Accrual Method	76		154
Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	1,442			1,444
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	1,458			1,443
Impaired Financing Receivable, with Related Allowance, Recorded Investment	10,636	[1]		11,554	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	10,748			11,476
Impaired Financing Receivable, Related Allowance	(392)			(392)
Impaired Financing Receivable, Recorded Investment	12,078			12,998
Impaired Financing Receivable, Unpaid Principal Balance	12,206			12,919
Financing Receivable, Recorded Investment, Nonaccrual Status	6,103	[3]		5,835	[4]
Impaired Financing Receivable, Average Recorded Investment	12,538		14,197
Impaired Financing Receivable, Interest Income, Accrual Method	122		194
Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0			0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0			0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]		0	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0			0
Impaired Financing Receivable, Related Allowance	0			0
Impaired Financing Receivable, Recorded Investment	0			0
Impaired Financing Receivable, Unpaid Principal Balance	0			0
Financing Receivable, Recorded Investment, Nonaccrual Status	0	[3]		0	[4]
Impaired Financing Receivable, Average Recorded Investment	0		2,169
Impaired Financing Receivable, Interest Income, Accrual Method	0		0
Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, with No Related Allowance, Recorded Investment	0			0
Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance	0			0
Impaired Financing Receivable, with Related Allowance, Recorded Investment	0	[1]		119	[2]
Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance	0			115
Impaired Financing Receivable, Related Allowance	0			(3)
Impaired Financing Receivable, Recorded Investment	0			119
Impaired Financing Receivable, Unpaid Principal Balance	0			115
Financing Receivable, Recorded Investment, Nonaccrual Status	0	[3]		0	[4]
Impaired Financing Receivable, Average Recorded Investment	60		1,023
Impaired Financing Receivable, Interest Income, Accrual Method	0		0
Less than 90 days past due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	9,100	[3]		9,600	[4]
Collateral Dependent Not Individually Analyzed [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired Financing Receivable, Related Allowance	(1,300)			(1,300)
Impaired Financing Receivable, Recorded Investment	$ 60,700			$ 65,100
Impaired Financing Receivable, Impairment analysis performed percent	65.00%	[1]		67.00%

[1] Impairment analysis was performed in the aggregate in consideration of similar risk characteristics of the assets and historical statistics on $60.7 million (65 percent) of impaired loans as of March 31, 2014, which resulted in a specific reserve of $1.3 million.

[2] Impairment analysis was performed in the aggregate in consideration of similar risk characteristics of the assets and historical statistics on $65.1 million (67 percent) of impaired loans as of December 31, 2012, which resulted in a specific reserve of $1.3 million.

[3] Includes $9.1 million of loans that are less than 90 days delinquent but which have not met Farmer Mac's performance criteria for returning to accrual status.

[4] Includes $9.6 million of loans that are less than 90 days delinquent but which have not met Farmer Mac's performance criteria for returning to accrual status.