Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 25,008
Remaining Life - 1 - 5 Years	42,654
Remaining Life - 6 - 10 Years	22,235
Remaining Life - 11 - 30 Years	13,640
Remaining Life Over - 30 Years	1,928
Remaining Life - Total Years	105,465
Interest rate contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	5,230	[1]
Remaining Life - 1 - 5 Years	33,709	[1]
Remaining Life - 6 - 10 Years	19,936	[1]
Remaining Life - 11 - 30 Years	13,109	[1]
Remaining Life Over - 30 Years	1,638	[1]
Remaining Life - Total Years	$ 73,622	[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	$ 329	[2]
Remaining Life - 1 - 5 Years	120	[2]
Remaining Life - 6 - 10 Years	327	[2]
Remaining Life - 11 - 30 Years	514	[2]
Remaining Life Over - 30 Years		[2]
Remaining Life - Total Years	$ 1,290	[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	$ 19,346
Remaining Life - 1 - 5 Years	8,825
Remaining Life - 6 - 10 Years	1,972
Remaining Life - 11 - 30 Years	17
Remaining Life Over - 30 Years	290
Remaining Life - Total Years	30,450
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 June 30, 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 June 30, 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.