Business Segment Reporting - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Total interest income	$ 49,180	$ 62,975	$ 61,745	$ 61,498	$ 56,151	$ 63,810	$ 71,578	$ 73,131	$ 235,398	[1]	$ 264,670	$ 274,687
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									0		0	0
Interest Expense	(35,777)	(34,787)	(33,584)	(33,128)	(33,358)	(33,448)	(36,961)	(38,923)	(137,276)	[2]	(142,690)	(153,382)
Net interest income	13,403	28,188	28,161	28,370	22,793	30,362	34,617	34,208	98,122		121,980	121,305
Guaranty Fee Income	6,768	6,819	6,759	6,612	6,568	6,401	6,064	5,930	26,958		24,963	24,821
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									38,813	[3]	(21,228)	(72,210)
Non-interest Income/(loss)	17,022	9,821	26,483	12,445	8,374	8,464	(27,281)	14,178	65,771		3,735	(47,389)
(Release of/(provision for) loan losses	(117)	499	529	(430)	(4,354)	(137)	1,220	(420)	481		(3,691)	(610)
Provision for/(release of) losses									(929)		1,816	2,957
Noninterest Expense, Excluding Loan, Lease and Other Losses									(32,178)		(32,724)	(31,616)
Noninterest Expense	(7,621)	(8,441)	(7,964)	(9,081)	(6,109)	(7,748)	(9,209)	(7,842)	(33,107)	[4]	(30,908)	(28,659)
Income/(loss) before income taxes	22,687	30,067	47,209	31,304	20,704	30,941	(653)	40,124	131,267		91,116	44,647
Income tax (benefit)/expense	(3,774)	(8,226)	(13,036)	(8,716)	(4,837)	(8,294)	2,629	(11,654)	(33,752)		(22,156)	(5,797)
Net income	18,913	21,841	34,173	22,588	15,867	22,647	1,976	28,470	97,515		68,960	38,850
Preferred stock dividends	(882)	(881)	(881)	(851)	(720)	(719)	(720)	(720)	(3,495)		(2,879)	(2,879)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	(5,546)	(5,547)	(5,547)	(5,547)	(5,546)	(5,547)	(5,547)	(5,547)	(22,187)		(22,187)	(22,187)
Net Income (Loss) Available to Common Stockholders, Basic	12,485	15,413	27,745	16,190	9,601	16,381	(4,291)	22,203	71,833		43,894	13,784
Total assets at carrying value	13,361,780				12,622,201				13,361,780		12,622,201	11,883,508
On and Off Balance Sheet Program Assets, At Principal Balance	13,950,312				13,015,188				13,950,312		13,015,188	11,913,302
Farm & Ranch [Member]
Segment Reporting Information [Line Items]
Segment interest and dividend income operating									121,570	[1]	131,714	146,653
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									(964)		(1,659)	(3,269)
Segment interest expense									(53,978)	[2]	(65,460)	(92,155)
Segment net effective spread									66,628		64,595	51,229
Segment guarantee fee income									23,690		22,095	22,525
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									2,244	[3]	2,427	3,201
Segment non interest income									25,934		24,522	25,726
(Release of/(provision for) loan losses									481		(3,691)	(610)
Provision for/(release of) losses									(929)		1,816	2,957
Noninterest Expense, Excluding Loan, Lease and Other Losses									(15,292)		(15,066)	(15,768)
Noninterest Expense									(16,221)	[4]	(13,250)	(12,811)
Segment core earnings before income taxes									76,822		72,176	63,534
Income tax (benefit)/expense									(26,888)		(25,261)	(22,237)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends									49,934		46,915	41,297
Preferred stock dividends									0		0	0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends									0		0	0
Segment core earnings									49,934		46,915	41,297
Total assets at carrying value	5,821,292				5,190,136				5,821,292		5,190,136	4,840,519
On and Off Balance Sheet Program Assets, At Principal Balance	9,672,730				9,056,489				9,672,730		9,056,489	8,057,027
USDA Guarantees [Member]
Segment Reporting Information [Line Items]
Segment interest and dividend income operating									53,384	[1]	56,815	56,726
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									0		0	0
Segment interest expense									(42,174)	[2]	(45,560)	(45,937)
Segment net effective spread									11,210		11,255	10,789
Segment guarantee fee income									132		163	204
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									791	[3]	599	283
Segment non interest income									923		762	487
(Release of/(provision for) loan losses									0		0	0
Provision for/(release of) losses									0		0	0
Noninterest Expense, Excluding Loan, Lease and Other Losses									(3,161)		(3,065)	(2,752)
Noninterest Expense									(3,161)	[4]	(3,065)	(2,752)
Segment core earnings before income taxes									8,972		8,952	8,524
Income tax (benefit)/expense									(3,140)		(3,134)	(2,983)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends									5,832		5,818	5,541
Preferred stock dividends									0		0	0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends									0		0	0
Segment core earnings									5,832		5,818	5,541
Total assets at carrying value	1,656,688				1,641,030				1,656,688		1,641,030	1,552,105
On and Off Balance Sheet Program Assets, At Principal Balance	1,687,117				1,615,579				1,687,117		1,615,579	1,513,177
Rural Utilities [Member]
Segment Reporting Information [Line Items]
Segment interest and dividend income operating									58,921	[1]	63,243	53,237
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									0		0	0
Segment interest expense									(47,842)	[2]	(50,796)	(40,950)
Segment net effective spread									11,079		12,447	12,287
Segment guarantee fee income									4,100		4,364	5,361
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									0	[3]	466	0
Segment non interest income									4,100		4,830	5,361
(Release of/(provision for) loan losses									0		0	0
Provision for/(release of) losses									0		0	0
Noninterest Expense, Excluding Loan, Lease and Other Losses									(5,465)		(5,809)	(4,923)
Noninterest Expense									(5,465)	[4]	(5,809)	(4,923)
Segment core earnings before income taxes									9,714		11,468	12,725
Income tax (benefit)/expense									(3,400)		(4,013)	(4,454)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends									6,314		7,455	8,271
Preferred stock dividends									0		0	0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends									0		0	0
Segment core earnings									6,314		7,455	8,271
Total assets at carrying value	2,566,896				2,398,809				2,566,896		2,398,809	2,421,904
On and Off Balance Sheet Program Assets, At Principal Balance	2,590,465				2,343,120				2,590,465		2,343,120	2,343,098
Corporate [Member]
Segment Reporting Information [Line Items]
Segment interest and dividend income operating									21,940	[1]	24,729	28,117
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									0		0	0
Segment interest expense									(5,606)	[2]	(6,469)	(13,003)
Segment net effective spread									16,334		18,260	15,114
Segment guarantee fee income									0		0	0
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									1,622	[3]	(2,113)	(2,272)
Segment non interest income									1,622		(2,113)	(2,272)
(Release of/(provision for) loan losses									0		0	0
Provision for/(release of) losses									0		0	0
Noninterest Expense, Excluding Loan, Lease and Other Losses									(8,260)		(8,784)	(8,173)
Noninterest Expense									(8,260)	[4]	(8,784)	(8,173)
Segment core earnings before income taxes									9,696		7,363	4,669
Income tax (benefit)/expense									8,798		7,157	8,195
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends									18,494		14,520	12,864
Preferred stock dividends									(3,495)		(2,879)	(2,879)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends									(22,187)		(22,187)	(22,187)
Segment core earnings									(7,188)		(10,546)	(12,202)
Total assets at carrying value	3,316,904				3,392,226				3,316,904		3,392,226	3,068,980
On and Off Balance Sheet Program Assets, At Principal Balance	0				0				0		0	0
Reconciling Adjustments [Member]
Segment Reporting Information [Line Items]
Segment interest and dividend income operating									(20,417)	[1]	(11,831)	(10,046)
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income									964		1,659	3,269
Segment interest expense									12,324	[2]	25,595	38,663
Segment net effective spread									(7,129)		15,423	31,886
Segment guarantee fee income									(964)		(1,659)	(3,269)
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees									34,156	[3]	(22,607)	(73,422)
Segment non interest income									33,192		(24,266)	(76,691)
(Release of/(provision for) loan losses									0		0	0
Provision for/(release of) losses									0		0	0
Noninterest Expense, Excluding Loan, Lease and Other Losses									0		0	0
Noninterest Expense									0	[4]	0	0
Segment core earnings before income taxes									26,063	[5]	(8,843)	(44,805)
Income tax (benefit)/expense									(9,122)		3,095	15,682
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends									16,941	[5]	(5,748)	(29,123)
Preferred stock dividends									0		0	0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends									0		0	0
Segment core earnings									16,941	[5]	(5,748)	(29,123)
Total assets at carrying value	0				0				0		0	0
On and Off Balance Sheet Program Assets, At Principal Balance	$ 0				$ 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.

[2] 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 "Gains/(losses) on financial derivatives and hedging activities" on the consolidated financial statements.

[3] 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.

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

[5] 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.