Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 46,057
Remaining Life - 1 - 5 Years	62,910
Remaining Life - 6 - 10 Years	30,552
Remaining Life - 11 - 30 Years	34,818
Remaining Life Over - 30 Years	8,167
Remaining Life - Total Years	182,504
Interest Rate Contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	15,089
Remaining Life - 1 - 5 Years	48,226
Remaining Life - 6 - 10 Years	24,802
Remaining Life - 11 - 30 Years	33,300
Remaining Life Over - 30 Years	1,831
Remaining Life - Total Years	$ 123,248
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	$ 146
Remaining Life - 1 - 5 Years	370
Remaining Life - 6 - 10 Years	1,013
Remaining Life - 11 - 30 Years	1,507
Remaining Life Over - 30 Years	42
Remaining Life - Total Years	$ 3,078
Derivative maturity date	Jun. 17, 2050
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 30,822
Remaining Life - 1 - 5 Years	14,314
Remaining Life - 6 - 10 Years	4,343
Remaining Life - 11 - 30 Years	11
Remaining Life Over - 30 Years	6,294
Remaining Life - Total Years	55,784
Credit contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life - 6 - 10 Years	394
Remaining Life - Total Years	$ 394