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
	Jun. 30, 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	$ 3,437,556	$ 5,091,600
USDA Securities [Member]
Schedule of Available-for-sale and Trading Securities [Line Items]
Available-for-sale, at fair value	1,636,930	1,553,669
Trading, at fair value	46,099	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	5,060,382	6,678,377
Available-for-sale Securities, Amortized Cost Basis	5,064,292	6,682,569
Available-for-Sale Gross Unrealized Gains	44,053	67,473
Available-for-sale Securities, Unrealized Losses	(33,859)	(104,773)
Available-for-sale, at fair value	5,074,486	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	1,640,650
Available-for-Sale Securities Unpaid Principal Balance	3,431,068	5,087,944
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	1,656,454
Available-for-sale Securities, Amortized Cost Basis	3,430,601	5,087,551
Available-for-Sale Gross Unrealized Gains	38,337	64,720
Available-for-sale Securities, Unrealized Losses	(31,382)	(60,671)
Available-for-sale, at fair value	3,437,556	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	3,410,393	5,066,855
Available-for-sale Securities, Amortized Cost Basis	3,410,393	5,066,980
Available-for-Sale Gross Unrealized Gains	37,497	64,051
Available-for-sale Securities, Unrealized Losses	(31,378)	(60,665)
Available-for-sale, at fair value	3,416,512	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	20,675	21,089
Available-for-sale Securities, Amortized Cost Basis	20,208	20,571
Available-for-Sale Gross Unrealized Gains	840	669
Available-for-sale Securities, Unrealized Losses	(4)	(6)
Available-for-sale, at fair value	21,044	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	1,629,314	1,590,433
Available-for-sale Securities, Amortized Cost Basis	1,633,691	1,595,018
Available-for-Sale Gross Unrealized Gains	5,716	2,753
Available-for-sale Securities, Unrealized Losses	(2,477)	(44,102)
Available-for-sale, at fair value	1,636,930	1,553,669
Trading Securities Unpaid Principal Balance	43,684	55,373
Trading Securities Amortized Cost	47,881	60,345
Trading Securities, Unrealized Gains	147	193
Trading Securities, Unrealized Losses	(1,929)	(2,194)
Trading, at fair value	46,099	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]
Held-to-Maturity Securities, Debt Maturities, Next Twelve Months, Weighted-Average Yield	5.75%
Debt Instrument, Unamortized Discount (Premium), Net	15,804
Held-to-maturity Securities, Unrecognized Holding Gain	4,161
Held-to-maturity Securities, Unrecognized Holding Loss	(567)
Held-to-maturity Securities, Fair Value	1,660,048
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	3,910	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	(467)	(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	(467)	(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	4,377	4,585
Trading Securities [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	$ 4,197	$ 4,972