Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) $ in Millions	Sep. 30, 2020 USD ($)
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 49,465
Remaining Life - 1 - 5 Years	76,335
Remaining Life - 6 - 10 Years	34,126
Remaining Life - 11 - 30 Years	37,471
Remaining Life Over - 30 Years	8,231
Remaining Life - Total Years	205,628
Interest rate contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	14,583
Remaining Life - 1 - 5 Years	55,297
Remaining Life - 6 - 10 Years	27,601
Remaining Life - 11 - 30 Years	35,879
Remaining Life Over - 30 Years	377
Remaining Life - Total Years	133,737
Foreign currency contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	176
Remaining Life - 1 - 5 Years	387
Remaining Life - 6 - 10 Years	967
Remaining Life - 11 - 30 Years	1,580
Remaining Life Over - 30 Years
Remaining Life - Total Years	3,110
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	34,706
Remaining Life - 1 - 5 Years	20,651
Remaining Life - 6 - 10 Years	5,504
Remaining Life - 11 - 30 Years	12
Remaining Life Over - 30 Years	7,854
Remaining Life - Total Years	68,727
Credit contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life - 6 - 10 Years	54
Remaining Life - Total Years	$ 54