Business Segment Reporting - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]
Total interest income	$ 49,718	[1]	$ 61,498
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0
Interest Expense	(34,726)	[2]	(33,128)
Net interest income	14,992		28,370
Guaranty Fee Income	6,518		6,612
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	(6,819)	[3]	5,833
Non-interest Income/(loss)	(301)		12,445
Provision for loan losses	(573)		(430)
Provision for/(release of) losses	(101)		(746)
Noninterest Expense, Excluding Loan, Lease and Other Losses	(7,846)		(8,335)
Noninterest Expense	(7,947)	[4]	(9,081)
Income/(loss) before income taxes	6,171		31,304
Income tax (benefit)/expense	1,141		(8,716)
Net income	7,312		22,588
Preferred stock dividends	(952)		(851)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	(5,547)		(5,547)
Net Income (Loss) Available to Common Stockholders, Basic	813		16,190
Total assets at carrying value	13,554,353		12,892,672		13,361,780
On and Off Balance Sheet Program Assets, At Principal Balance	14,108,203		13,437,862
Farm & Ranch [Member]
Segment Reporting Information [Line Items]
Total interest income	18,339	[1]	15,416
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	(531)		(180)
Interest Expense	(10,230)	[2]	(7,153)
Net interest income	7,578		8,083
Guaranty Fee Income	3,909		3,671
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	130	[3]	595
Non-interest Income/(loss)	4,039		4,266
Provision for loan losses	(573)		(430)
Provision for/(release of) losses	(101)		(746)
Noninterest Expense, Excluding Loan, Lease and Other Losses	(3,552)		(3,804)
Noninterest Expense	(3,653)	[4]	(4,550)
Segment core earnings before income taxes	7,391		7,369
Income tax (benefit)/expense	(2,587)		(2,579)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	4,804		4,790
Preferred stock dividends	0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0
Segment core earnings	4,804		4,790
Total assets at carrying value	2,272,643		1,762,977
On and Off Balance Sheet Program Assets, At Principal Balance	5,293,975		4,782,609
USDA Guarantees [Member]
Segment Reporting Information [Line Items]
Total interest income	12,959	[1]	13,341
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0
Interest Expense	(9,603)	[2]	(8,647)
Net interest income	3,356		4,694
Guaranty Fee Income	26		33
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	28	[3]	200
Non-interest Income/(loss)	54		233
Provision for loan losses	0		0
Provision for/(release of) losses	0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(731)		(749)
Noninterest Expense	(731)	[4]	(749)
Segment core earnings before income taxes	2,679		4,178
Income tax (benefit)/expense	(938)		(1,462)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	1,741		2,716
Preferred stock dividends	0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0
Segment core earnings	1,741		2,716
Total assets at carrying value	1,691,056		1,701,413
On and Off Balance Sheet Program Assets, At Principal Balance	1,686,696		1,648,105
Rural Utilities [Member]
Segment Reporting Information [Line Items]
Total interest income	7,744	[1]	8,989
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0
Interest Expense	(5,543)	[2]	(5,806)
Net interest income	2,201		3,183
Guaranty Fee Income	877		948
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	0	[3]	0
Non-interest Income/(loss)	877		948
Provision for loan losses	0		0
Provision for/(release of) losses	0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(777)		(802)
Noninterest Expense	(777)	[4]	(802)
Segment core earnings before income taxes	2,301		3,329
Income tax (benefit)/expense	(805)		(1,165)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	1,496		2,164
Preferred stock dividends	0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0
Segment core earnings	1,496		2,164
Total assets at carrying value	1,030,422		1,072,494
On and Off Balance Sheet Program Assets, At Principal Balance	1,027,246		1,039,698
Institutional Credit [Member] [Member]
Segment Reporting Information [Line Items]
Total interest income	17,646	[1]	19,298	[1]
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0
Interest Expense	(11,315)	[2]	(13,435)	[2]
Net interest income	6,331		5,863
Guaranty Fee Income	2,237		2,140
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	0	[3]	0	[3]
Non-interest Income/(loss)	2,237		2,140
Provision for loan losses	0		0
Provision for/(release of) losses	0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(445)		(459)
Noninterest Expense	(445)	[4]	(459)	[4]
Segment core earnings before income taxes	8,123		7,544
Income tax (benefit)/expense	(2,843)		(2,640)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	5,280		4,904
Preferred stock dividends	0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0
Segment core earnings	5,280		4,904
Total assets at carrying value	5,157,887		5,093,825
On and Off Balance Sheet Program Assets, At Principal Balance	6,100,286		5,967,450
Corporate [Member]
Segment Reporting Information [Line Items]
Total interest income	5,235	[1]	5,734
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	0		0
Interest Expense	(999)	[2]	(1,294)
Net interest income	4,236		4,440
Guaranty Fee Income	0		0
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	(571)	[3]	(562)
Non-interest Income/(loss)	(571)		(562)
Provision for loan losses	0		0
Provision for/(release of) losses	0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	(2,341)		(2,521)
Noninterest Expense	(2,341)	[4]	(2,521)
Segment core earnings before income taxes	1,324		1,357
Income tax (benefit)/expense	2,839		1,765
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	4,163		3,122
Preferred stock dividends	(952)		(851)
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	(5,547)		(5,547)
Segment core earnings	(2,336)		(3,276)
Total assets at carrying value	3,402,345		3,261,963
On and Off Balance Sheet Program Assets, At Principal Balance
Reconciling Adjustments [Member]
Segment Reporting Information [Line Items]
Total interest income	(12,205)	[1]	(1,280)
Interest income related to consolidated trusts owned by third parties reclassified to guarantee fee income	531		180
Interest Expense	2,964	[2]	3,207
Net interest income	(8,710)		2,107
Guaranty Fee Income	(531)		(180)
Other Non-Interest Income (Expense), Excluding Guarantee and Commitment Fees	(6,406)	[3]	5,600
Non-interest Income/(loss)	(6,937)		5,420
Provision for loan losses	0		0
Provision for/(release of) losses	0		0
Noninterest Expense, Excluding Loan, Lease and Other Losses	0		0
Noninterest Expense	0	[4]	0
Segment core earnings before income taxes	(15,647)	[5]	7,527
Income tax (benefit)/expense	5,475		(2,635)
Segment core earnings before preferred stock dividends and attribution of income to non-controlling interest - preferred stock dividends	(10,172)	[5]	4,892
Preferred stock dividends	0		0
Less: Net Income attributable to non-controlling Interest - preferred stock dividends	0		0
Segment core earnings	(10,172)	[5]	4,892
Total assets at carrying value	0		0
On and Off Balance Sheet Program Assets, At Principal Balance	$ 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 "(Losses)/gains 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.