Investment Securities (Proceeds and Gross Realized Gains And Losses from Sales of Securities Available for Sale) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023		Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Proceeds	$ 1,849	$ 3,949	$ 2,900	[1]	$ 13,470	[1]
Gross realized gains	0	25	0		140
Gross realized losses	$ 11	$ 20	$ 20		$ 123

[1] Certain prior period amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.