Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year		$ 39,153
Remaining Life - 1 - 5 Years		61,441
Remaining Life - 6 - 10 Years		25,671
Remaining Life - 11 - 30 Years		31,042
Remaining Life Over - 30 Years		6,008
Remaining Life - Total Years		163,315	$ 137,497
Interest Rate Contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	[1]	11,341
Remaining Life - 1 - 5 Years	[1]	53,011
Remaining Life - 6 - 10 Years	[1]	20,948
Remaining Life - 11 - 30 Years	[1]	29,556
Remaining Life Over - 30 Years	[1]	1,713
Remaining Life - Total Years	[1]	$ 116,569
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]	$ 218
Remaining Life - 1 - 5 Years	[2]	383
Remaining Life - 6 - 10 Years	[2]	961
Remaining Life - 11 - 30 Years	[2]	1,473
Remaining Life Over - 30 Years	[2]	101
Remaining Life - Total Years	[2]	$ 3,136
Derivative maturity date		Feb. 26, 2050
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year		$ 27,594
Remaining Life - 1 - 5 Years		7,992
Remaining Life - 6 - 10 Years		3,762
Remaining Life - 11 - 30 Years		13
Remaining Life Over - 30 Years		4,194
Remaining Life - Total Years		43,555
Credit contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life - 1 - 5 Years		55
Remaining Life - Total Years		$ 55

[1] As of December 31, 2019, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was April 20, 2067.

[2] As of December 31, 2019, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was February 26, 2050.