Derivative Financial Instruments (Schedule Of Outstanding Hedges: (Notional Amount)) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	$ 3,872	$ 1,886
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	238,008	52,383
Swap Agreements [Member] | Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	3,872	1,886
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	1,431	140
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	1,324	130
Futures [Member] | Interest-Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	66,620	25,253
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	1,033,045	637,847
Forwards [Member] | Foreign Exchange Contracts [Member] | Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	2,613
Options Purchased [Member] | Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	11,215	14,299
Options Written [Member] | Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	12,342	14,587
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	105	155
Stable Value Contracts [Member] | Other Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount of Derivatives	$ 40,963	$ 46,758