Loans and Allowance for Losses and Concentrations of Credit Risk - Financing Receivables Credit Quality Indicators (Details) - USD ($) $ in Thousands		Dec. 31, 2016		Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[2]	$ 6,139,304		$ 5,725,299
Financing Receivable, Recorded Investment, Past Due	[3]	21,038	[1]	32,136	[4]
Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	5,845,308		5,509,463
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	128,803		111,336
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	165,193		104,500
Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,410,498		3,243,651
Financing Receivable, Recorded Investment, Past Due		13,822	[1]	5,167	[4]
Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,281,371		3,168,216
Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	55,645		46,677
Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	73,482		28,758
Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,037,440		941,411
Financing Receivable, Recorded Investment, Past Due		3,652	[1]	7,405	[4]
Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	971,477		904,373
Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	18,020		9,842
Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	47,943		27,196
Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,305,844		1,236,781
Financing Receivable, Recorded Investment, Past Due		707	[1]	7,059	[4]
Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,228,840		1,162,475
Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	48,416		48,438
Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	28,588		25,868
Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	324,074		211,125
Financing Receivable, Recorded Investment, Past Due		2,857	[1]	2,667	[4]
Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	304,728		192,531
Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	6,716		5,856
Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	12,630		12,738
Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	48,051		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]	46,082		72,152
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]	1,969		9,838
Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	13,397		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]	12,810		9,716
Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	6		523
Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	581		102
On-balance sheet [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,514,454		2,957,975
Financing Receivable, Recorded Investment, Past Due	[3]	19,757	[1]	26,935	[4]
On-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	3,352,959		2,837,487
On-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	73,809		63,106
On-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	87,686		57,382
On-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,157,098		1,923,842
Financing Receivable, Recorded Investment, Past Due		13,449	[1]	4,656	[4]
On-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,080,227		1,888,762
On-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	35,223		22,255
On-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	41,648		12,825
On-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	597,130		454,901
Financing Receivable, Recorded Investment, Past Due		3,245	[1]	7,405	[4]
On-balance sheet [Member] | Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	568,221		431,038
On-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	1,139		2,616
On-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	27,770		21,247
On-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	548,517		450,278
Financing Receivable, Recorded Investment, Past Due		669	[1]	2,517	[4]
On-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	504,784		409,003
On-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	33,075		35,317
On-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	10,658		5,958
On-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	191,270		99,973
Financing Receivable, Recorded Investment, Past Due		2,394	[1]	2,519	[4]
On-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	179,288		89,541
On-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	4,372		2,918
On-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	7,610		7,514
On-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	11,545		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]	11,545		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]	8,894		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]	8,894		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]	2,624,850		2,767,324
Financing Receivable, Recorded Investment, Past Due	[3]	1,281	[1]	5,201	[4]
Off-balance sheet [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	2,492,349		2,671,976
Off-balance sheet [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	54,994		48,230
Off-balance sheet [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	77,507		47,118
Off-balance sheet [Member] | Crops [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,253,400		1,319,809
Financing Receivable, Recorded Investment, Past Due		373	[1]	511	[4]
Off-balance sheet [Member] | Crops [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	1,201,144		1,279,454
Off-balance sheet [Member] | Crops [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	20,422		24,422
Off-balance sheet [Member] | Crops [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	31,834		15,933
Off-balance sheet [Member] | Permanent Plantings [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	440,310		486,510
Financing Receivable, Recorded Investment, Past Due		407	[1]	0	[4]
Off-balance sheet [Member] | Permanent Plantings [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	403,256		473,335
Off-balance sheet [Member] | Permanent Plantings [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	16,881		7,226
Off-balance sheet [Member] | Permanent Plantings [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	20,173		5,949
Off-balance sheet [Member] | Livestock [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	757,327		786,503
Financing Receivable, Recorded Investment, Past Due		38	[1]	4,542	[4]
Off-balance sheet [Member] | Livestock [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	724,056		753,472
Off-balance sheet [Member] | Livestock [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	15,341		13,121
Off-balance sheet [Member] | Livestock [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	17,930		19,910
Off-balance sheet [Member] | Part-Time Farm [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	132,804		111,152
Financing Receivable, Recorded Investment, Past Due		463	[1]	148	[4]
Off-balance sheet [Member] | Part-Time Farm [Member] | Acceptable [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	125,440		102,990
Off-balance sheet [Member] | Part-Time Farm [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	2,344		2,938
Off-balance sheet [Member] | Part-Time Farm [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	5,020		5,224
Off-balance sheet [Member] | Agriculture Storage and Processing [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	36,506		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]	34,537		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]	0		0
Off-balance sheet [Member] | Agriculture Storage and Processing [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	1,969		0
Off-balance sheet [Member] | Other Commodity [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1]	4,503		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]	3,916		6,517
Off-balance sheet [Member] | Other Commodity [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[5]	6		523
Off-balance sheet [Member] | Other Commodity [Member] | Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	[1],[6]	$ 581		$ 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 with at least one missed payment, 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.