Farmer Mac Guaranteed Securities and USDA Guaranteed Securities - Farmer Mac Guaranteed Securities and USDA Securities (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended
Mar. 30, 2015	Dec. 31, 2014	Mar. 31, 2015
Farmer Mac Guaranteed Securities and USDA Securities [Member]
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Unpaid Principal Balance		$ 5,370,717	$ 5,548,607
Available-for-sale Securities, Amortized Cost Basis		5,373,437	5,550,942
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		48,529	104,510
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		31,463	18,399
Available-for-sale, at fair value		5,390,503	5,637,053
Farmer Mac Guaranteed Securities [Member]
Held-to-Maturity Securities [Abstract]
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment			1,767,096
Held-to-maturity Securities, Fair Value			1,783,076
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Unpaid Principal Balance		3,652,904	3,805,333
Available-for-sale Securities, Amortized Cost Basis		3,652,462	3,804,972
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		36,679	55,581
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		29,860	18,344
Available-for-sale, at fair value		3,659,281	3,842,209
USDA Securities [Member]
Available-for-sale Securities [Abstract]
Available-for-sale, at fair value		1,731,222	1,794,844
Trading Securities [Abstract]
Trading, at fair value		40,310	37,593
Available-for-sale Securities [Member] \| Farmer Mac Guaranteed Securities and USDA Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		2,720	2,335
Available-for-sale Securities [Member] \| Farmer Mac Guaranteed Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		(442)	(361)
Institutional Credit [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		2,400	2,400
Institutional Credit [Member] \| Farmer Mac Guaranteed Securities [Member]
Held-to-Maturity Securities [Abstract]
Held-to-Maturity Unpaid Principal Balance		1,785,340	1,761,169
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment		1,794,620	1,767,096
Held to Maturity; Unrealized Holding Gains		6,211	15,980
Held to Maturity - Unrealized Holding Loss		(255)	0
Held-to-maturity Securities, Fair Value		1,800,576	1,783,076
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Unpaid Principal Balance		3,625,073	3,782,235
Available-for-sale Securities, Amortized Cost Basis		3,625,073	3,782,235
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		36,442	54,813
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		29,853	18,344
Available-for-sale, at fair value		3,631,662	3,818,704
Institutional Credit [Member] \| Held-to-maturity Securities [Member] \| Farmer Mac Guaranteed Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		9,280	5,927
Institutional Credit [Member] \| Available-for-sale Securities [Member] \| Farmer Mac Guaranteed Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		0	0
USDA Guarantees [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		(200)	400
USDA Guarantees [Member] \| Farmer Mac Guaranteed Securities [Member]
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Unpaid Principal Balance		27,831	23,098
Available-for-sale Securities, Amortized Cost Basis		27,389	22,737
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		237	768
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		7	0
Available-for-sale, at fair value		27,619	23,505
USDA Guarantees [Member] \| USDA Securities [Member]
Available-for-sale Securities [Abstract]
Available-for-Sale Securities Unpaid Principal Balance		1,717,813	1,743,274
Available-for-sale Securities, Amortized Cost Basis		1,720,975	1,745,970
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax		11,850	48,929
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		1,603	55
Available-for-sale, at fair value		1,731,222	1,794,844
Trading Securities [Abstract]
Trading Securities Unpaid Principal Balance		38,412	35,699
Trading Securities, Debt, Amortized Cost		41,160	38,277
Trading Securities, Unrealized Gains	120	114
Trading Securities, Unrealized Holding Loss	804	964
Trading, at fair value		40,310	37,593
USDA Guarantees [Member] \| Available-for-sale Securities [Member] \| Farmer Mac Guaranteed Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		(442)	(361)
USDA Guarantees [Member] \| Available-for-sale Securities [Member] \| USDA Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		3,162	2,696
USDA Guarantees [Member] \| Trading Securities [Member] \| USDA Securities [Member]
Schedule of Held-to-Maturity, Available-for-sale, and Trading Securities [Line Items]
Unamortized Premium/(Discount)		$ 2,748	$ 2,578

Available-for-Sale Securities Unpaid Principal Balance

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Held-to-Maturity Unpaid Principal Balance

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Trading Securities Unpaid Principal Balance

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

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Amount before other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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Amortized cost of investments in debt securities classified as trading.

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Amount of unrealized holding gain before loss recognized in the income statement for investments in trading securities.

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