Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Accumulated net unrealized losses on investment securities:
Balance at beginning of period, net of tax	$ (2,319)	$ (99)
Net unrealized holding gains (losses) arising during the period	97	(1,826)
Less: Provision (benefit) for income taxes	24	(430)
Change in net unrealized losses on investment securities, net of tax	73	(1,396)
Balance at end of period, net of tax	(2,246)	(1,495)
Accumulated net losses on cash flow hedges:
Balance at beginning of period, net of tax	(942)	55
Net cash flow hedge losses arising during the period	(389)	(408)
Less: Benefit for income taxes	(91)	(96)
Change in net cash flow hedge losses arising during the period, net of tax	(298)	(312)
Net cash flow (losses) gains included in interest and fees on loans	(269)	47
Less: (Benefit) provision for income taxes	(63)	11
Reclassification adjustment for net cash flow hedge (losses) gains included in net income, net of tax	(206)	36
Change in net cash flow hedge losses, net of tax	(92)	(348)
Balance at end of period, net of tax	(1,034)	(293)
Accumulated defined benefit pension and other postretirement plans adjustment:
Balance at beginning of period, net of tax	(481)	(168)
Amortization of actuarial net loss	18	14
Amortization of prior service credit	(11)	(12)
Total amounts recognized in other noninterest expenses	7	2
Less: Provision for income taxes	2	0
Adjustment for amounts recognized as components of net periodic benefit credit during the period, net of tax	5	2
Change in defined benefit pension and other postretirement plans adjustment, net of tax	5	2
Balance at end of period, net of tax	(476)	(166)
Total accumulated other comprehensive loss at end of period, net of tax	(3,756)	$ (1,954)	$ (3,742)
Cash flow hedge loss to be reclassified within 12 months	$ 496