Derivative Instruments (Maturity Of The Notional Amounts Of Derivative Financial Instruments) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	$ 37,930
Remaining Life - 1 - 5 Years	24,147
Remaining Life - 6 - 10 Years	58,605
Remaining Life - 11 - 30 Years	28,947
Remaining Life Over - 30 Years	3,807
Remaining Life - Total Years	153,436
Interest rate contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	10,664	[1]
Remaining Life - 1 - 5 Years	17,545	[1]
Remaining Life - 6 - 10 Years	54,294	[1]
Remaining Life - 11 - 30 Years	27,414	[1]
Remaining Life Over - 30 Years	500	[1]
Remaining Life - Total Years	110,417	[1]
Foreign currency contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	290	[2]
Remaining Life - 1 - 5 Years	318	[2]
Remaining Life - 6 - 10 Years	863	[2]
Remaining Life - 11 - 30 Years	1,520	[2]
Remaining Life Over - 30 Years	56	[2]
Remaining Life - Total Years	3,047	[2]
Equity market contracts [Member]
Maturity of the notional amounts of derivative financial instruments
Remaining Life Less Than 1 Year	26,976
Remaining Life - 1 - 5 Years	6,284
Remaining Life - 6 - 10 Years	3,448
Remaining Life - 11 - 30 Years	13
Remaining Life Over - 30 Years	3,251
Remaining Life - Total Years	$ 39,972

[1] As of September 30, 2019, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was June 23, 2021.

[2] June 23, 2021.⁽²⁾As of September 30, 2019, the latest maturity date for which we were hedging our exposure to the variability in future cash flows for these instruments was February 20, 2050.