Loans and Allowance for Losses and Concentrations of Credit Risk - Financing Receivables Credit Quality Indicators (Details) - USD ($) $ in Thousands		Mar. 31, 2016		Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[2]	$ 5,713,789		$ 5,725,299
Financing Receivable, Recorded Investment, Past Due	[3]	34,680	[1]	32,136	[4]
Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,480,634		5,509,463
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	127,418		111,336
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	105,737		104,500
Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,257,137		3,243,651
Financing Receivable, Recorded Investment, Past Due		12,477	[1]	5,167	[4]
Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,176,303		3,168,216
Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	43,989		46,677
Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	36,845		28,758
Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	936,290		941,411
Financing Receivable, Recorded Investment, Past Due		10,867	[1]	7,405	[4]
Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	879,814		904,373
Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	30,133		9,842
Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	26,343		27,196
Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,213,181		1,236,781
Financing Receivable, Recorded Investment, Past Due		8,195	[1]	7,059	[4]
Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,137,756		1,162,475
Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	46,380		48,438
Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	29,045		25,868
Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	238,472		211,125
Financing Receivable, Recorded Investment, Past Due		3,141	[1]	2,667	[4]
Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	220,905		192,531
Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	4,164		5,856
Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	13,403		12,738
Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	59,870		81,990
Financing Receivable, Recorded Investment, Past Due		0	[1]	9,838	[4]
Agriculture Storage and Processing [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	57,670		72,152
Agriculture Storage and Processing [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,200		0
Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		9,838
Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	8,839		10,341
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]	8,186		9,716
Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	552		523
Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	101		102
On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,022,458		2,957,975
Financing Receivable, Recorded Investment, Past Due	[3]	29,184	[1]	26,935	[4]
On-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,926,023		2,837,487
On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	39,149		63,106
On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	57,286		57,382
On-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,959,238		1,923,842
Financing Receivable, Recorded Investment, Past Due		11,785	[1]	4,656	[4]
On-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,928,285		1,888,762
On-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	9,875		22,255
On-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	21,078		12,825
On-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	461,129		454,901
Financing Receivable, Recorded Investment, Past Due		10,867	[1]	7,405	[4]
On-balance sheet [Member] | Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	440,033		431,038
On-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	1,200		2,616
On-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	19,896		21,247
On-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	459,224		450,278
Financing Receivable, Recorded Investment, Past Due		3,873	[1]	2,517	[4]
On-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	425,346		409,003
On-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	25,178		35,317
On-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	8,700		5,958
On-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	123,705		99,973
Financing Receivable, Recorded Investment, Past Due		2,659	[1]	2,519	[4]
On-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	113,197		89,541
On-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,896		2,918
On-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	7,612		7,514
On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	15,501		25,782
Financing Receivable, Recorded Investment, Past Due		0	[1]	9,838	[4]
On-balance sheet [Member] | Agriculture Storage and Processing [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	15,501		15,944
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]	0		9,838
On-balance sheet [Member] | Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,661		3,199
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]	3,661		3,199
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]	2,691,331		2,767,324
Financing Receivable, Recorded Investment, Past Due	[3]	5,496	[1]	5,201	[4]
Off-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,554,611		2,671,976
Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	88,269		48,230
Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	48,451		47,118
Off-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,297,899		1,319,809
Financing Receivable, Recorded Investment, Past Due		692	[1]	511	[4]
Off-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,248,018		1,279,454
Off-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	34,114		24,422
Off-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	15,767		15,933
Off-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	475,161		486,510
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]	439,781		473,335
Off-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	28,933		7,226
Off-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	6,447		5,949
Off-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	753,957		786,503
Financing Receivable, Recorded Investment, Past Due		4,322	[1]	4,542	[4]
Off-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	712,410		753,472
Off-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	21,202		13,121
Off-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	20,345		19,910
Off-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	114,767		111,152
Financing Receivable, Recorded Investment, Past Due		482	[1]	148	[4]
Off-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	107,708		102,990
Off-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	1,268		2,938
Off-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,791		5,224
Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	44,369		56,208
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]	42,169		56,208
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,200		0
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	0		0
Off-balance sheet [Member] | Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,178		7,142
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]	4,525		6,517
Off-balance sheet [Member] | Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	552		523
Off-balance sheet [Member] | Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	$ 101		$ 102

[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.