Investment Securities (Summary Of Investment Securities In Unrealized Loss Positions) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 3,075	$ 8,504
Less than 12 Months, Unrealized Losses	246	771
12 months or more, Fair Value	14,340	10,506
12 Months or more, Unrealized Losses	2,690	2,262
Total, Fair Value	17,415	19,010
Total, Unrealized Losses	2,936	3,033
U.S. Treasury securities
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	996
Less than 12 Months, Unrealized Losses	0	5
12 months or more, Fair Value	1,672	1,668
12 Months or more, Unrealized Losses	123	141
Total, Fair Value	1,672	2,664
Total, Unrealized Losses	123	146
Residential mortgage-backed securities
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	537	3,500
Less than 12 Months, Unrealized Losses	41	361
12 months or more, Fair Value	10,525	8,153
12 Months or more, Unrealized Losses	2,201	1,967
Total, Fair Value	11,062	11,653
Total, Unrealized Losses	2,242	2,328
Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	2,538	4,008
Less than 12 Months, Unrealized Losses	205	405
12 months or more, Fair Value	2,143	685
12 Months or more, Unrealized Losses	366	154
Total, Fair Value	4,681	4,693
Total, Unrealized Losses	$ 571	$ 559