Derivative Financial Instruments (Schedule Of Outstanding Hedges: (Notional Amount)) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	$ 3,153		$ 3,872
Swap Agreements And Forwards [Member] | Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	1,578	[1]	238,008	[1]
Options And Caps Purchased [Member] | Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	68	[1]	1,431	[1]
Options And Caps Written [Member] | Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	68	[1]	1,324	[1]
Futures [Member] | Interest rate contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	1,910	[1]	66,620	[1]
Forward, Swap And Spot [Member] | Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	897,354		1,033,045
Options Purchased [Member] | Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	9,454		11,215
Options Written [Member] | Foreign exchange contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	8,734		12,342
Credit Default Swap Agreements [Member] | Credit Derivative Contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	27		105
Stable Value Contracts [Member] | Other Contracts [Member] | Derivatives not designated as hedging instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	33,512		40,963
Swap Agreements [Member] | Interest rate contracts [Member] | Derivatives Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	3,153		3,872
Forwards [Member] | Foreign exchange contracts [Member] | Derivatives Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of derivatives	$ 3,477		$ 2,613

[1] Decline in notional amount compared to December 31, 2011 was associated with our withdrawal from our fixed-income trading initiative.