Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 14,136
Remaining Life - 1 - 5 Years	25,059
Remaining Life - 6 - 10 Years	18,341
Remaining Life - 11 - 30 Years	9,740
Remaining Life Over - 30 Years	1,214
Remaining Life - Total Years	68,490
Interest Rate Contract [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	3,174	[1]
Remaining Life - 1 - 5 Years	20,682	[1]
Remaining Life - 6 - 10 Years	12,917	[1]
Remaining Life - 11 - 30 Years	9,592	[1]
Remaining Life Over - 30 Years	1,213	[1]
Remaining Life - Total Years	47,578	[1]
Derivative maturity date	Jun. 01, 2042
Foreign Exchange Contract [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	255	[2]
Remaining Life - 1 - 5 Years	180	[2]
Remaining Life - 6 - 10 Years	200	[2]
Remaining Life - 11 - 30 Years	127	[2]
Remaining Life - Total Years	762	[2]
Derivative maturity date	Apr. 01, 2028
Equity Market Contract [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	10,707
Remaining Life - 1 - 5 Years	4,049
Remaining Life - 6 - 10 Years	5,224
Remaining Life - 11 - 30 Years	21
Remaining Life Over - 30 Years	1
Remaining Life - Total Years	20,002
Credit Risk Contract [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life - 1 - 5 Years	148
Remaining Life - Total Years	$ 148

[1] As of March 31, 2013, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was June 2042.

[2] As of March 31, 2013, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was April 2028.