Derivative Instruments Derivatives 2 - FV Gains and Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									$ 3,280		$ (3,626)		$ (6,562)
Accrual of periodic settlements	4,851	5,582	5,667	6,304	5,559	5,317	5,428	5,197	22,404		21,501		19,281
Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									2,779		(1,938)		(6,139)
Mortgage commitment derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									501		(1,688)		(423)
Pay-fixed Swap [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									14,393		(2,254)		(12,633)
Accrual of periodic settlements									(4,463)		(4,427)		(5,407)
Receive-fixed Swap [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									(10,721)		1,102		4,784
Accrual of periodic settlements									3,632		2,950		3,155
Basis Swap [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									(115)		78		60
Accrual of periodic settlements									44		21		26
Foreign Currency Swap [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									(101)		59		120
Accrual of periodic settlements									16		16		36
Pay-fixed Swaption [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									(238)		132		860
Receive-fixed Swaption [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									307		410		2,932
Other [Member] | Risk management derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative fair value gains (losses), net									21	[1]	(35)	[1]	(75)	[1]
Accrual of periodic settlements									$ 4	[1]	$ 10	[1]	$ 3	[1]

[1] Includes interest rate caps, futures, swap credit enhancements and mortgage insurance contracts.