Loans and Allowance for Losses and Concentrations of Credit Risk - Financing Receivables Credit Quality Indicators (Details) - USD ($) $ in Thousands		Dec. 31, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[2]	$ 5,725,299		$ 5,417,174
Financing Receivable, Recorded Investment, Past Due	[3]	32,136	[1]	18,917	[4]
Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,509,463		5,172,691
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	111,336		111,888
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	104,500		132,595
Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,243,651		2,941,266
Financing Receivable, Recorded Investment, Past Due		5,167	[1]	4,175	[4]
Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,168,216		2,887,319
Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	46,677		30,417
Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	28,758		23,530
Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	941,411		920,195
Financing Receivable, Recorded Investment, Past Due		7,405	[1]	6,869	[4]
Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	904,373		856,901
Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	9,842		18,180
Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	27,196		45,114
Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,236,781		1,260,618
Financing Receivable, Recorded Investment, Past Due		7,059	[1]	5,045	[4]
Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,162,475		1,174,057
Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	48,438		61,320
Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	25,868		25,241
Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	211,125		173,954
Financing Receivable, Recorded Investment, Past Due		2,667	[1]	2,828	[4]
Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	192,531		154,931
Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	5,856		1,963
Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	12,738		17,060
Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	81,990		114,360
Financing Receivable, Recorded Investment, Past Due		9,838	[1]	0	[4]
Agriculture Storage and Processing [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	72,152		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]	9,838		20,994
Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	10,341		6,781
Financing Receivable, Recorded Investment, Past Due		0	[1]	0	[4]
Other Commodity [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	9,716		6,117
Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	523		8
Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	102		656
On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,957,975		2,540,222
Financing Receivable, Recorded Investment, Past Due	[3]	26,935	[1]	18,427	[4]
On-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,837,487		2,419,285
On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	63,106		54,495
On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	57,382		66,442
On-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,923,842		1,633,667
Financing Receivable, Recorded Investment, Past Due		4,656	[1]	4,175	[4]
On-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,888,762		1,604,546
On-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	22,255		16,814
On-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	12,825		12,307
On-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	454,901		395,421
Financing Receivable, Recorded Investment, Past Due		7,405	[1]	6,869	[4]
On-balance sheet [Member] | Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	431,038		353,487
On-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,616		6,030
On-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	21,247		35,904
On-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	450,278		412,620
Financing Receivable, Recorded Investment, Past Due		2,517	[1]	4,555	[4]
On-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	409,003		375,010
On-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	35,317		31,039
On-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,958		6,571
On-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	99,973		69,511
Financing Receivable, Recorded Investment, Past Due		2,519	[1]	2,828	[4]
On-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	89,541		57,239
On-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,918		612
On-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	7,514		11,660
On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	25,782		29,003
Financing Receivable, Recorded Investment, Past Due		9,838	[1]	0	[4]
On-balance sheet [Member] | Agriculture Storage and Processing [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	15,944		29,003
On-balance sheet [Member] | Agriculture Storage and Processing [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
On-balance sheet [Member] | Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	9,838		0
On-balance sheet [Member] | Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,199		0
Financing Receivable, Recorded Investment, Past Due		0	[1]	0	[4]
On-balance sheet [Member] | Other Commodity [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,199		0
On-balance sheet [Member] | Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
On-balance sheet [Member] | Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		0
Off-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,767,324		2,876,952
Financing Receivable, Recorded Investment, Past Due	[3]	5,201	[1]	490	[4]
Off-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,671,976		2,753,406
Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	48,230		57,393
Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	47,118		66,153
Off-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,319,809		1,307,599
Financing Receivable, Recorded Investment, Past Due		511	[1]	0	[4]
Off-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,279,454		1,282,773
Off-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	24,422		13,603
Off-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	15,933		11,223
Off-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	486,510		524,774
Financing Receivable, Recorded Investment, Past Due		0	[1]	0	[4]
Off-balance sheet [Member] | Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	473,335		503,414
Off-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	7,226		12,150
Off-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,949		9,210
Off-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	786,503		847,998
Financing Receivable, Recorded Investment, Past Due		4,542	[1]	490	[4]
Off-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	753,472		799,047
Off-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	13,121		30,281
Off-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	19,910		18,670
Off-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	111,152		104,443
Financing Receivable, Recorded Investment, Past Due		148	[1]	0	[4]
Off-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	102,990		97,692
Off-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,938		1,351
Off-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,224		5,400
Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	56,208		85,357
Financing Receivable, Recorded Investment, Past Due		0	[1]	0	[4]
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	56,208		64,363
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	0		0
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		20,994
Off-balance sheet [Member] | Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	7,142		6,781
Financing Receivable, Recorded Investment, Past Due		0	[1]	0	[4]
Off-balance sheet [Member] | Other Commodity [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	6,517		6,117
Off-balance sheet [Member] | Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	523		8
Off-balance sheet [Member] | Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	$ 102		$ 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] 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.