Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year		$ 28,605
Remaining Life - 1 - 5 Years		39,696
Remaining Life - 6 - 10 Years		21,641
Remaining Life - 11 - 30 Years		13,911
Remaining Life Over - 30 Years		1,480
Remaining Life - Total Years		105,333	$ 83,976
Interest rate contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	[1]	10,408
Remaining Life - 1 - 5 Years	[1]	32,704
Remaining Life - 6 - 10 Years	[1]	18,554
Remaining Life - 11 - 30 Years	[1]	13,485
Remaining Life Over - 30 Years	[1]	1,213
Remaining Life - Total Years	[1]	$ 76,364
Derivative maturity date		Apr. 20, 2067
Foreign currency contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	[2]	$ 104
Remaining Life - 1 - 5 Years	[2]	138
Remaining Life - 6 - 10 Years	[2]	334
Remaining Life - 11 - 30 Years	[2]	$ 408
Remaining Life Over - 30 Years	[2]
Remaining Life - Total Years	[2]	$ 984
Derivative maturity date		Dec. 10, 2045
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year		$ 18,048
Remaining Life - 1 - 5 Years		6,796
Remaining Life - 6 - 10 Years		2,753
Remaining Life - 11 - 30 Years		18
Remaining Life Over - 30 Years		267
Remaining Life - Total Years		27,882
Credit contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year		45
Remaining Life - 1 - 5 Years		$ 58
Remaining Life - 6 - 10 Years
Remaining Life - 11 - 30 Years
Remaining Life Over - 30 Years
Remaining Life - Total Years		$ 103

[1] As of December 31, 2015, 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 December 31, 2015, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was December 2045.