Fair Value Disclosures - Unobservable Input Reconciliation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended						3 Months Ended		0 Months Ended		3 Months Ended								3 Months Ended				3 Months Ended								3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended				3 Months Ended
	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Available-for-sale Securities [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Available-for-sale Securities [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Available-for-sale Securities [Member]	Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Available-for-sale Securities [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]	Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Investment Securities [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Investment Securities [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Investment Securities [Member]	Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member] Investment Securities [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Floating Interest Rate [Member] Auction-rate certificates backed by Government guaranteed student loans [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Floating Interest Rate [Member] Auction-rate certificates backed by Government guaranteed student loans [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Floating Interest Rate [Member] Auction-rate certificates backed by Government guaranteed student loans [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Floating Interest Rate [Member] Auction-rate certificates backed by Government guaranteed student loans [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Floating Interest Rate [Member] Government/GSE Guaranteed Mortgage Backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Floating Interest Rate [Member] Government/GSE Guaranteed Mortgage Backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Floating Interest Rate [Member] Asset-backed Securities [Member]	Dec. 31, 2013 Floating Interest Rate [Member] Asset-backed Securities [Member]	Mar. 31, 2014 Floating Interest Rate [Member] Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]		Mar. 31, 2013 Floating Interest Rate [Member] Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]		Dec. 31, 2013 Floating Interest Rate [Member] Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]		Dec. 31, 2012 Floating Interest Rate [Member] Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member] Trading Account Assets [Member]		Mar. 31, 2014 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Mar. 31, 2014 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Asset-backed Securities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Farmer Mac Guaranteed Securities AgVantage [Member] Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Farmer Mac Guaranteed Securities AgVantage [Member] Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Farmer Mac Guaranteed Securities AgVantage [Member] Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Farmer Mac Guaranteed Securities AgVantage [Member] Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2013 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2013 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Farmer Mac Guarantee [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Mar. 31, 2014 Derivative Financial Instruments, Liabilities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Mar. 31, 2013 Derivative Financial Instruments, Liabilities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2013 Derivative Financial Instruments, Liabilities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2012 Derivative Financial Instruments, Liabilities [Member] Level 3 [Member] Fair Value, Measurements, Recurring [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 5,207,113	$ 6,823,086	$ 6,770,031	$ 6,421,447	$ 65,166	$ 65,446	$ 65,490	$ 63,159	$ 923	$ 1,129	$ 928	$ 1,247	$ 66,089	$ 66,575	$ 66,418	$ 64,406			$ 64,963	$ 65,213	$ 65,285	$ 63,159	$ 203	$ 205			$ 923	[1]	$ 1,129	[2]	$ 928	[1]	$ 1,247	[2]	$ 3,489,263	$ 5,100,080	$ 5,091,600	$ 4,766,258	$ 51,102	[3]	$ 87,271	[4]	$ 58,344	[3]	$ 104,188	[4]	$ 1,651,761	$ 1,656,431	$ 1,612,013	$ 1,590,783	$ 1,600,659	$ 1,569,160	$ 1,553,669	$ 1,486,595	$ 3,467,655	$ 5,072,882	$ 5,070,366	$ 4,739,577	$ 21,608	$ 27,198	$ 21,234	$ 26,681
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	237,984	547,420			0	233			0	0			0	233					0	0			0				0	[1]	0	[2]					170,000	425,000			0	[3]	0	[4]					67,984	122,187			67,984	122,187			170,000	425,000			0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	0	0			0	0			0	0			0	0					0	0			0				0	[1]	0	[2]					0	0			0	[3]	0	[4]					0	0			0	0			0	0			0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	244,801	164,763			4	0			283	314			287	314					0	0			4				283	[1]	314	[2]					176,440	78,316			7,619	[3]	16,931	[4]					68,074	86,133			60,455	69,202			176,269	77,933			171	383
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	3,405	(2,928)			0	0			278	196			278	196					0	0			0				278	[1]	196	[2]					2,750	(3,138)			377	[3]	14	[4]					377	14			0	0			2,750	(3,138)			0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	52,580	21,910			(320)	2,054			0	0			(320)	2,054					(322)	2,054			2				0	[1]	0	[2]					13,439	(9,724)			0	[3]	0	[4]					39,461	29,580			39,461	29,580			12,894	(10,624)			545	900
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	1,612,086				0				0				0						0				0				0								1,612,086				0								0				0				1,612,086				0
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	161	532	235	691																																																											161	[5]	532	[6]	235	[5]	691	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	0	0																																																													0	[5]	0	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales	0	0																																																													0	[5]	0	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	0	0																																																													0	[5]	0	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	74	159																																																													74	[5]	159	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0																																																													0	[5]	0	[6]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3	0																																																														0
Trading Securities, Unrealized Holding Loss																	$ 700	$ 100							$ 2,347	$ 2,625

[1] Unrealized gains are attributable to assets still held as of March 31, 2014 and are recorded in "Gains on trading assets."

[2] Unrealized gains are attributable to assets still held as of March 31, 2013 and are recorded in "Gains on trading assets."

[3] Includes unrealized gains of $0.7 million attributable to assets still held as of March 31, 2014 that are recorded in "Gains on trading assets."

[4] Includes unrealized losses of $0.1 million attributable to assets still held as of March 31, 2013 that are recorded in "Gains on trading assets."

[5] Unrealized gains are attributable to liabilities still held as of March 31, 2014 and are recorded in "(Losses)/gains on financial derivatives and hedging activities."

[6] Unrealized gains are attributable to liabilities still held as of March 31, 2013 and are recorded in "(Losses)/gains on financial derivatives and hedging activities."