Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($)
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 30,674
Remaining Life - 1 - 5 Years	41,426
Remaining Life - 6 - 10 Years	25,885
Remaining Life - 11 - 30 Years	16,074
Remaining Life Over - 30 Years	1,497
Remaining Life - Total Years	115,556
Interest rate contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	10,685	[1]
Remaining Life - 1 - 5 Years	33,426	[1]
Remaining Life - 6 - 10 Years	23,461	[1]
Remaining Life - 11 - 30 Years	15,608	[1]
Remaining Life Over - 30 Years	1,213	[1]
Remaining Life - Total Years	$ 84,393	[1]
Derivative maturity date	Apr. 01, 2067
Foreign currency contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 120	[2]
Remaining Life - 1 - 5 Years	120	[2]
Remaining Life - 6 - 10 Years	327	[2]
Remaining Life - 11 - 30 Years	$ 449	[2]
Remaining Life Over - 30 Years		[2]
Remaining Life - Total Years	$ 1,016	[2]
Derivative maturity date	Dec. 01, 2045
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 19,766
Remaining Life - 1 - 5 Years	7,880
Remaining Life - 6 - 10 Years	2,097
Remaining Life - 11 - 30 Years	17
Remaining Life Over - 30 Years	284
Remaining Life - Total Years	30,044
Credit contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 103
Remaining Life - 1 - 5 Years
Remaining Life - 6 - 10 Years
Remaining Life - 11 - 30 Years
Remaining Life Over - 30 Years
Remaining Life - Total Years	$ 103

[1] As of March 31, 2016, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was April 2067.

[2] As of March 31, 2016, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was December 2045.