Loans and Allowance for Losses and Concentrations of Credit Risk - Financing Receivables Credit Quality Indicators (Details) - USD ($) $ in Thousands		Jun. 30, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[2]	$ 5,485,570		$ 5,417,174
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[3]	31,852	[1]	18,917	[4]
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,234,064		5,172,691
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	115,084		111,888
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	136,422		132,595
On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,710,493		2,540,222
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[3]	26,140	[1]	18,427	[4]
On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,585,642		2,419,285
On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	50,210		54,495
On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	74,641		66,442
Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,775,077		2,876,952
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due	[3]	5,712	[1]	490	[4]
Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,648,422		2,753,406
Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	64,874		57,393
Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	61,781		66,153
Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,036,565		2,941,266
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		4,185	[1]	4,175	[4]
Crops [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,956,536		2,887,319
Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	48,030		30,417
Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	31,999		23,530
Crops [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,768,682		1,633,667
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		1,296	[1]	4,175	[4]
Crops [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,735,454		1,604,546
Crops [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	12,856		16,814
Crops [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	20,372		12,307
Crops [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,267,883		1,307,599
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		2,889	[1]	0	[4]
Crops [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,221,082		1,282,773
Crops [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	35,174		13,603
Crops [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	11,627		11,223
Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	948,128		920,195
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		21,214	[1]	6,869	[4]
Permanent Plantings [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	891,918		856,901
Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	10,185		18,180
Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	46,025		45,114
Permanent Plantings [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	416,206		395,421
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		20,606	[1]	6,869	[4]
Permanent Plantings [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	377,534		353,487
Permanent Plantings [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		6,030
Permanent Plantings [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	38,672		35,904
Permanent Plantings [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	531,922		524,774
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		608	[1]	0	[4]
Permanent Plantings [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	514,384		503,414
Permanent Plantings [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	10,185		12,150
Permanent Plantings [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	7,353		9,210
Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,216,229		1,260,618
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		3,916	[1]	5,045	[4]
Livestock [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,139,620		1,174,057
Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	53,218		61,320
Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	23,391		25,241
Livestock [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	423,122		412,620
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		1,802	[1]	4,555	[4]
Livestock [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	382,150		375,010
Livestock [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	34,854		31,039
Livestock [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	6,118		6,571
Livestock [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	793,107		847,998
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		2,114	[1]	490	[4]
Livestock [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	757,470		799,047
Livestock [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	18,364		30,281
Livestock [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	17,273		18,670
Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	181,555		173,954
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		2,537	[1]	2,828	[4]
Part-Time Farm [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	163,175		154,931
Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	3,643		1,963
Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	14,737		17,060
Part-Time Farm [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	77,332		69,511
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		2,436	[1]	2,828	[4]
Part-Time Farm [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	65,353		57,239
Part-Time Farm [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,500		612
Part-Time Farm [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	9,479		11,660
Part-Time Farm [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	104,223		104,443
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		101	[1]	0	[4]
Part-Time Farm [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	97,822		97,692
Part-Time Farm [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	1,143		1,351
Part-Time Farm [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,258		5,400
Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	97,004		114,360
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Agriculture Storage and Processing [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	77,370		93,366
Agriculture Storage and Processing [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	19,634		20,994
Agriculture Storage and Processing [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	25,071		29,003
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Agriculture Storage and Processing [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	25,071		29,003
Agriculture Storage and Processing [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
Agriculture Storage and Processing [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		0
Agriculture Storage and Processing [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	71,933		85,357
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Agriculture Storage and Processing [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	52,299		64,363
Agriculture Storage and Processing [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
Agriculture Storage and Processing [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	19,634		20,994
Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	6,089		6,781
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Other Commodity [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,445		6,117
Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	8		8
Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	636		656
Other Commodity [Member] | On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	80		0
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Other Commodity [Member] | On-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	80		0
Other Commodity [Member] | On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
Other Commodity [Member] | On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		0
Other Commodity [Member] | Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	6,009		6,781
Financing Receivable, Recorded Investment, Equal to Greater than 90 Days Past Due		0	[1]	0	[4]
Other Commodity [Member] | Off-balance sheet [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,365		6,117
Other Commodity [Member] | Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	8		8
Other Commodity [Member] | Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	$ 636		$ 656

[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] Geographic regions: Northwest (AK, ID, MT, OR, WA, WY); Southwest (AZ, CA, CO, HI, NM, NV, UT); Mid-North (IA, IL, IN, MI, MN, NE, ND, SD, WI); Mid-South (AR, KS, LA, MO, OK, TX); Northeast (CT, DE, KY, MA, MD, ME, NH, NJ, NY, OH, PA, RI, VA, VT, WV); Southeast (AL, FL, GA, MS, NC, SC, TN).

[3] Includes loans and loans underlying off-balance sheet Farm & Ranch Guaranteed Securities and LTSPCs that are 90 days or more past due, in foreclosure, or in bankruptcy, excluding loans performing under either their original loan terms or a court-approved bankruptcy plan.

[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.

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

[6] 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.