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. 31, 2014	Dec. 31, 2013
Farmer Mac Guaranteed Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-sale, at fair value	$ 3,489,263	$ 5,091,600
USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-sale, at fair value	1,600,659	1,553,669
Trading, at fair value	51,102	58,344
Payment Guarantee [Member] | Farmer Mac Guaranteed Securities and USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-Sale Securities Unpaid Principal Balance	5,089,787	6,678,377
Available-for-sale Securities, Amortized Cost Basis	5,093,884	6,682,569
Available-for-Sale Gross Unrealized Gains	44,121	67,473
Available-for-sale Securities, Unrealized Losses	(48,083)	(104,773)
Available-for-sale, at fair value	5,089,922	6,645,269
Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Held-to-Maturity Unpaid Principal Balance	1,641,150
Available-for-Sale Securities Unpaid Principal Balance	3,491,831	5,087,944
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	1,660,270
Available-for-sale Securities, Amortized Cost Basis	3,491,337	5,087,551
Available-for-Sale Gross Unrealized Gains	36,775	64,720
Available-for-sale Securities, Unrealized Losses	(38,849)	(60,671)
Available-for-sale, at fair value	3,489,263	5,091,600
Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed Securities AgVantage [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-Sale Securities Unpaid Principal Balance	3,470,937	5,066,855
Available-for-sale Securities, Amortized Cost Basis	3,470,937	5,066,980
Available-for-Sale Gross Unrealized Gains	35,565	64,051
Available-for-sale Securities, Unrealized Losses	(38,847)	(60,665)
Available-for-sale, at fair value	3,467,655	5,070,366
Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-Sale Securities Unpaid Principal Balance	20,894	21,089
Available-for-sale Securities, Amortized Cost Basis	20,400	20,571
Available-for-Sale Gross Unrealized Gains	1,210	669
Available-for-sale Securities, Unrealized Losses	(2)	(6)
Available-for-sale, at fair value	21,608	21,234
USDA Guarantee [Member] | USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-Sale Securities Unpaid Principal Balance	1,597,956	1,590,433
Available-for-sale Securities, Amortized Cost Basis	1,602,547	1,595,018
Available-for-Sale Gross Unrealized Gains	7,346	2,753
Available-for-sale Securities, Unrealized Losses	(9,234)	(44,102)
Available-for-sale, at fair value	1,600,659	1,553,669
Trading Securities Unpaid Principal Balance	48,283	55,373
Trading Securities Amortized Cost	52,724	60,345
Trading Securities, Unrealized Gains	151	193
Trading Securities, Unrealized Losses	(1,773)	(2,194)
Trading, at fair value	51,102	58,344
Held-to-maturity Securities [Member] | Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	19,120
Available-for-sale Securities [Member] | Payment Guarantee [Member] | Farmer Mac Guaranteed Securities and USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	4,097	4,192
Available-for-sale Securities [Member] | Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	(494)	(393)
Available-for-sale Securities [Member] | Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed Securities AgVantage [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	0	125
Available-for-sale Securities [Member] | Farmer Mac Guarantee [Member] | Farmer Mac Guaranteed USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	(494)	(518)
Available-for-sale Securities [Member] | USDA Guarantee [Member] | USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	4,591	4,585
Trading Account Assets [Member] | USDA Guarantee [Member] | Trading Securities, USDA Guaranteed Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net	$ 4,441	$ 4,972