Investment Securities (Contractual Maturity Distribution Of Debt Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Schedule of Investments [Line Items]
Amortized Cost	$ 20,351	$ 22,045
Fair Value	17,415	$ 19,012
Debt securities
Schedule of Investments [Line Items]
Available-for-sale, Within one year, Amortized Cost	356
Available-for-sale, After one year through five years, Amortized Cost	1,681
Available-for-sale, After five years through ten years, Amortized Cost	5,427
Available-for-sale, After ten years, Amortized Cost	12,887
Amortized Cost	20,351
Available-for-sale, Within one year, Fair Value	344
Available-for-sale, After one year through five years, Fair Value	1,559
Available-for-sale, After five years through ten years, Fair Value	4,848
Available-for-sale, After ten years, Fair Value	10,664
Fair Value	$ 17,415