Business Segment Reporting - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]
Total interest income	$ 61,775	[1]	$ 61,745	[2]	$ 111,493	[1]	$ 123,243	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0		0		0
Interest Expense	(42,502)	[3]	(33,584)	[4]	(77,228)	[3]	(66,712)	[4]
Net interest income	19,273		28,161		34,265		56,531
Guaranty Fee Income	6,403		6,759		12,921		13,371
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	2,561	[5]	19,724	[6]	(4,258)	[5]	25,557	[6]
Non-interest Income/(loss)	8,964		26,483		8,663		38,928
Provision for loan losses	1,583		529		1,010		99
Provision for/(release of) losses	974		175		873		(571)
Noninterest Expense, Excluding Loan, Lease and Other Losses	(8,830)		(8,139)		(16,676)		(16,474)
Noninterest Expense	(7,856)	[7]	(7,964)	[7]	(15,803)	[7]	(17,045)	[7]
Income/(loss) before income taxes	21,964		47,209		28,135		78,513
Income tax (benefit)/expense	6,368		(13,036)		7,509		(21,752)
Net income	28,332		34,173		35,644		56,761
Preferred stock dividends	(2,308)		(881)		(3,260)		(1,732)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	(5,819)		(5,547)		(11,366)		(11,094)
Net Income (Loss) Available to Common Stockholders, Basic	20,205		27,745		21,018		43,935
Total assets at carrying value	14,670,102		12,935,951		14,670,102		12,935,951		13,361,780
On and Off Balance Sheet Program Assets, At Principal Balance	14,072,542		13,595,518		14,072,542		13,595,518
Farm & Ranch [Member]
Segment Reporting Information [Line Items]
Total interest income	19,598	[1]	16,046	[2]	37,936	[1]	31,462	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	(513)		(195)		(1,044)		(375)
Interest Expense	(11,265)	[3]	(7,623)	[4]	(21,958)	[3]	(14,776)	[4]
Net interest income	7,820		8,228		14,934		16,311
Guaranty Fee Income	3,807		3,703		7,716		7,374
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	242	[5]	1,299	[6]	373	[5]	1,894	[6]
Non-interest Income/(loss)	4,049		5,002		8,089		9,268
Provision for loan losses	1,583		529		1,010		99
Provision for/(release of) losses	974		175		873		(571)
Noninterest Expense, Excluding Loan, Lease and Other Losses	(3,914)		(3,795)		(7,466)		(7,599)
Noninterest Expense	(2,940)	[7]	(3,620)	[7]	(6,593)	[7]	(8,170)	[7]
Segment core earnings before income taxes	10,512		10,139		17,440		17,508
Income tax (benefit)/expense	(3,679)		(3,549)		(6,103)		(6,128)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	6,833		6,590		11,337		11,380
Preferred stock dividends	0		0		0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0		0		0
Segment core earnings	6,833		6,590		11,337		11,380
Total assets at carrying value	2,387,899		1,925,419		2,387,899		1,925,419
On and Off Balance Sheet Program Assets, At Principal Balance	5,310,664		4,917,489		5,310,664		4,917,489
USDA Guarantees [Member]
Segment Reporting Information [Line Items]
Total interest income	13,307	[1]	13,157	[2]	26,266	[1]	26,498	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0				0		0
Interest Expense	(9,148)	[3]	(8,649)	[4]	(18,323)	[3]	(17,296)	[4]
Net interest income	4,159		4,508		7,943		9,202
Guaranty Fee Income	23		42		49		75
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	9	[5]	317	[6]	36	[5]	517	[6]
Non-interest Income/(loss)	32		359		85		592
Provision for loan losses	0		0		0		0
Provision for/(release of) losses	0				0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(764)		(708)		(1,495)		(1,457)
Noninterest Expense	(764)	[7]	(708)	[7]	(1,495)	[7]	(1,457)	[7]
Segment core earnings before income taxes	3,427		4,159		6,533		8,337
Income tax (benefit)/expense	(1,200)		(1,456)		(2,288)		(2,918)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	2,227		2,703		4,245		5,419
Preferred stock dividends	0		0		0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0		0		0
Segment core earnings	2,227		2,703		4,245		5,419
Total assets at carrying value	1,721,003		1,659,134		1,721,003		1,659,134
On and Off Balance Sheet Program Assets, At Principal Balance	1,710,335		1,667,170		1,710,335		1,667,170
Rural Utilities [Member]
Segment Reporting Information [Line Items]
Total interest income	6,782	[1]	8,981	[2]	14,525	[1]	17,970	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0				0		0
Interest Expense	(3,829)	[3]	(5,925)	[4]	(9,582)	[3]	(11,731)	[4]
Net interest income	2,953		3,056		4,943		6,239
Guaranty Fee Income	0		0		0		948
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	0	[5]	0	[6]	0	[5]	0	[6]
Non-interest Income/(loss)	0		0		0		948
Provision for loan losses	0		0		0		0
Provision for/(release of) losses	0				0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(830)		(771)		(1,607)		(1,573)
Noninterest Expense	(830)	[7]	(771)	[7]	(1,607)	[7]	(1,573)	[7]
Segment core earnings before income taxes	2,123		2,285		3,336		5,614
Income tax (benefit)/expense	(743)		(800)		(1,168)		(1,965)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	1,380		1,485		2,168		3,649
Preferred stock dividends	0		0		0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0		0		0
Segment core earnings	1,380		1,485		2,168		3,649
Total assets at carrying value	1,022,421		1,091,561		1,022,421		1,091,561
On and Off Balance Sheet Program Assets, At Principal Balance	1,012,313		1,049,920		1,012,313		1,049,920
Institutional Credit [Member] [Member]
Segment Reporting Information [Line Items]
Total interest income	17,373	[1]	19,329	[1],[2]	35,021	[1]	38,627	[1],[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0				0		0
Interest Expense	(10,116)	[3]	(13,352)	[3],[4]	(21,092)	[3]	(26,787)	[3],[4]
Net interest income	7,257		5,977		13,929		11,840
Guaranty Fee Income	3,086		3,209		6,200		5,349
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	0	[5]	0	[5],[6]	0	[5]	0	[5],[6]
Non-interest Income/(loss)	3,086		3,209		6,200		5,349
Provision for loan losses	0		0		0		0
Provision for/(release of) losses	0				0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(492)		(441)		(937)		(900)
Noninterest Expense	(492)	[7]	(441)	[7]	(937)	[7]	(900)	[7]
Segment core earnings before income taxes	9,851		8,745		19,192		16,289
Income tax (benefit)/expense	(3,447)		(3,061)		(6,717)		(5,701)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	6,404		5,684		12,475		10,588
Preferred stock dividends	0		0		0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0		0		0
Segment core earnings	6,404		5,684		12,475		10,588
Total assets at carrying value	5,115,147		5,083,860		5,115,147		5,083,860
On and Off Balance Sheet Program Assets, At Principal Balance	6,039,230		5,960,939		6,039,230		5,960,939
Corporate [Member]
Segment Reporting Information [Line Items]
Total interest income	5,185	[1]	5,471	[2]	10,420	[1]	11,205	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0				0		0
Interest Expense	(1,025)	[3]	(1,177)	[4]	(2,118)	[3]	(2,471)	[4]
Net interest income	4,160		4,294		8,302		8,734
Guaranty Fee Income	0		0		0		0
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	(603)	[5]	2,782	[6]	(1,174)	[5]	2,220	[6]
Non-interest Income/(loss)	(603)		2,782		(1,174)		2,220
Provision for loan losses	0		0		0		0
Provision for/(release of) losses	0				0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(2,830)		(2,424)		(5,171)		(4,945)
Noninterest Expense	(2,830)	[7]	(2,424)	[7]	(5,171)	[7]	(4,945)	[7]
Segment core earnings before income taxes	727		4,652		1,957		6,009
Income tax (benefit)/expense	13,803		1,859		16,676		3,624
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	14,530		6,511		18,633		9,633
Preferred stock dividends	(2,308)		(881)		(3,260)		(1,732)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	(5,819)		(5,547)		(11,366)		(11,094)
Segment core earnings	6,403		83		4,007		(3,193)
Total assets at carrying value	4,423,632		3,175,977		4,423,632		3,175,977
On and Off Balance Sheet Program Assets, At Principal Balance
Reconciling Adjustments [Member]
Segment Reporting Information [Line Items]
Total interest income	(470)	[1]	(1,239)	[2]	(12,675)	[1]	(2,519)	[2]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	513		195		1,044		375
Interest Expense	(7,119)	[3]	3,142	[4]	(4,155)	[3]	6,349	[4]
Net interest income	(7,076)		2,098		(15,786)		4,205
Guaranty Fee Income	(513)		(195)		(1,044)		(375)
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	2,913	[5]	15,326	[6]	(3,493)	[5]	20,926	[6]
Non-interest Income/(loss)	2,400		15,131		(4,537)		20,551
Provision for loan losses	0		0		0		0
Provision for/(release of) losses	0		0		0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	0		0		0		0
Noninterest Expense	0	[7]	0	[7]	0	[7]	0	[7]
Segment core earnings before income taxes	(4,676)	[8]	17,229	[8]	(20,323)	[8]	24,756	[8]
Income tax (benefit)/expense	1,634		(6,029)		7,109		(8,664)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	(3,042)	[8]	11,200	[8]	(13,214)	[8]	16,092	[8]
Preferred stock dividends	0		0		0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0		0		0
Segment core earnings	(3,042)	[8]	11,200	[8]	(13,214)	[8]	16,092	[8]
Total assets at carrying value	0		0		0		0
On and Off Balance Sheet Program Assets, At Principal Balance	$ 0		$ 0		$ 0		$ 0

[1] Includes reconciling adjustments for the amortization of premiums and discounts on assets consolidated at fair value to reflect core earnings amounts and interest income related to securities purchased under agreements to resell.

[2] Includes reconciling adjustments for the amortization of premiums and discounts on assets consolidated at fair value to reflect core earnings amounts.

[3] Based on effective funding cost determined for each operating segment, including expenses related to interest rate swaps not designated as hedges, which are included in "(Losses)/gains on financial derivatives and hedging activities" on the consolidated financial statements. Includes reconciling adjustments for interest expense related to securities sold, not yet purchased.

[4] Based on effective funding cost determined for each operating segment, including expenses related to interest rate swaps not designated as hedges, which are included in "(Losses)/gains on financial derivatives and hedging activities" on the consolidated financial statements.

[5] Includes interest income and interest expense related to securities purchased under agreements to resell and securities sold, not yet purchased, respectively; reconciling adjustments for the reclassification of expenses related to interest rate swaps not designated as hedges and fair value adjustments on financial derivatives and trading assets; and a reconciling adjustment related to the recognition of deferred gains over the estimated lives of certain Farmer Mac Guaranteed Securities and USDA Securities.

[6] Includes reconciling adjustments for the reclassification of expenses related to interest rate swaps not designated as hedges and fair value adjustments on financial derivatives and trading assets. Also includes a reconciling adjustment related to the recognition of deferred gains over the estimated lives of certain Farmer Mac Guaranteed Securities and USDA Securities.

[7] Includes directly attributable costs and an allocation of indirectly attributable costs based on headcount.

[8] Net adjustments to reconcile core earnings before income taxes; core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends; and segment core earnings to corresponding income measures: income before income taxes, net income, and net income attributable to common stockholders, respectively.