Loans and Allowance for Losses and Concentrations of Credit Risk - Financing Receivables Credit Quality Indicators (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 5,293,975	[1]	$ 5,163,080	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	29,437	[1]	28,296	[2]
Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,761,595	[1]	2,666,857	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	8,718	[1]	8,256	[2]
Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	908,046	[1]	907,824	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	11,820	[1]	11,841	[2]
Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,281,827	[1]	1,246,105	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	5,721	[1]	4,462	[2]
Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	157,794	[1]	162,743	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	3,178	[1]	3,618	[2]
Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	175,525	[1]	170,918	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	0	[2]
Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	9,188	[1]	8,633	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	119	[2]
On-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,222,958	[1]	2,135,467	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	28,373	[1]	27,580	[2]
On-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,415,131	[1]	1,385,008	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	8,529	[1]	8,036	[2]
On-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	346,430	[1]	336,478	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	11,415	[1]	11,841	[2]
On-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	368,826	[1]	330,509	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	5,251	[1]	4,462	[2]
On-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	49,529	[1]	50,362	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	3,178	[1]	3,122	[2]
On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	41,717	[1]	32,636	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	0	[2]
On-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,325	[1]	474	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	119	[2]
Off-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	3,071,017	[1]	3,027,613	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	1,064	[1]	716	[2]
Off-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,346,464	[1]	1,281,849	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	189	[1]	220	[2]
Off-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	561,616	[1]	571,346	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	405	[1]	0	[2]
Off-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	913,001	[1]	915,596	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	470	[1]	0	[2]
Off-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	108,265	[1]	112,381	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	496	[2]
Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	133,808	[1]	138,282	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	0	[2]
Off-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	7,863	[1]	8,159	[1]
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	0	[1]	0	[2]
Special Mention [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	122,727	[1],[3]	122,830	[1],[3]
Special Mention [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	24,457	[1],[3]	26,633	[1],[3]
Special Mention [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	17,872	[1],[3]	20,594	[1],[3]
Special Mention [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	50,458	[1],[3]	55,912	[1],[3]
Special Mention [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,459	[1],[3]	1,835	[1],[3]
Special Mention [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	26,910	[1],[3]	17,278	[1],[3]
Special Mention [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	571	[1],[3]	578	[1],[3]
Special Mention [Member] | On-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	39,162	[1],[3]	47,171	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	11,985	[1],[3]	15,656	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	4,371	[1],[3]	4,973	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	13,303	[1],[3]	19,357	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,407	[1],[3]	918	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	8,096	[1],[3]	6,267	[1],[3]
Special Mention [Member] | On-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	0	[1],[3]	0	[1],[3]
Special Mention [Member] | Off-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	83,565	[1],[3]	75,659	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	12,472	[1],[3]	10,977	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	13,501	[1],[3]	15,621	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	37,155	[1],[3]	36,555	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,052	[1],[3]	917	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	18,814	[1],[3]	11,011	[1],[3]
Special Mention [Member] | Off-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	571	[1],[3]	578	[1],[3]
Pass [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	4,988,712	[1]	4,845,302	[1]
Pass [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,698,043	[1]	2,600,039	[1]
Pass [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	840,952	[1]	838,318	[1]
Pass [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,187,929	[1]	1,144,438	[1]
Pass [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	139,318	[1]	144,611	[1]
Pass [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	113,955	[1]	110,059	[1]
Pass [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	8,515	[1]	7,837	[1]
Pass [Member] | On-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,090,415	[1]	1,988,945	[1]
Pass [Member] | On-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,383,292	[1]	1,348,205	[1]
Pass [Member] | On-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	302,195	[1]	290,064	[1]
Pass [Member] | On-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	346,330	[1]	300,308	[1]
Pass [Member] | On-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	37,198	[1]	39,022	[1]
Pass [Member] | On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	20,075	[1]	10,987	[1]
Pass [Member] | On-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,325	[1]	359	[1]
Pass [Member] | Off-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,898,297	[1]	2,856,357	[1]
Pass [Member] | Off-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,314,751	[1]	1,251,834	[1]
Pass [Member] | Off-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	538,757	[1]	548,254	[1]
Pass [Member] | Off-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	841,599	[1]	844,130	[1]
Pass [Member] | Off-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	102,120	[1]	105,589	[1]
Pass [Member] | Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	93,880	[1]	99,072	[1]
Pass [Member] | Off-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	7,190	[1]	7,478	[1]
Substandard [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	182,536	[1],[4]	194,948	[1],[4]
Substandard [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	39,095	[1],[4]	40,185	[1],[4]
Substandard [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	49,222	[1],[4]	48,912	[1],[4]
Substandard [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	43,440	[1],[4]	45,755	[1],[4]
Substandard [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	16,017	[1],[4]	16,297	[1],[4]
Substandard [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	34,660	[1],[4]	43,581	[1],[4]
Substandard [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	102	[1],[4]	218	[1],[4]
Substandard [Member] | On-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	93,381	[1],[4]	99,351	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	19,854	[1],[4]	21,147	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	39,864	[1],[4]	41,441	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	9,193	[1],[4]	10,844	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	10,924	[1],[4]	10,422	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	13,546	[1],[4]	15,382	[1],[4]
Substandard [Member] | On-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	0	[1],[4]	115	[1],[4]
Substandard [Member] | Off-balance sheet [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	89,155	[1],[4]	95,597	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Crops [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	19,241	[1],[4]	19,038	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Permanent Plantings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	9,358	[1],[4]	7,471	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Livestock [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	34,247	[1],[4]	34,911	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Part-Time Farm [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	5,093	[1],[4]	5,875	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	21,114	[1],[4]	28,199	[1],[4]
Substandard [Member] | Off-balance sheet [Member] | Other Commodity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 102	[1],[4]	$ 103	[1],[4]

[1] Amounts represent unpaid principal balance of risk-rated loans, which is the basis Farmer Mac uses to analyze its portfolio, and recorded investment of past due loans.

[2] (1)Amounts represent unpaid principal balance of risk-rated loans, which is the basis Farmer Mac uses to analyze its portfolio, and recorded investment of past due loans.

[3] Assets in the Special mention category generally have potential weaknesses due to performance issues but are currently considered to be adequately secured.

[4] Substandard assets have a well-defined weakness or weaknesses and there is a distinct possibility that some loss will be sustained if deficiencies are not corrected.