Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance at beginning of period, net of tax	$ (2,319)	$ (99)	$ 211
Net unrealized gains (losses) arising during the period	361	(2,903)	(406)
Investment Securities, Less: Provision (benefit) for income taxes	85	(683)	(96)
Investment securities, Change in net unrealized losses on investment securities, net of tax	276	(2,220)	(310)
Balance at end of period, net of tax	(2,043)	(2,319)	(99)
Cash Flow Hedges, Balance at beginning of period, net of tax	(942)	55	155
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net	34	(1,329)	(35)
Reclassification of loss related to de-designation of derivatives to other noninterest income	(195)	0	0
Cash flow hedges, Less: Benefit for income taxes	(38)	(313)	(8)
Change in net cash flow hedge (losses) gains arising during the period, net of tax	(123)	(1,016)	(27)
Net cash flow hedge (losses) gains recognized in interest and fees on loans before taxes	(576)	(25)	95
Amortization of unrealized losses related to de-designated derivatives	(26)	0	0
Benefit plans, Less: (Benefit) provision for income taxes	(142)	(6)	22
Reclassification adjustment for net cash flow hedge (losses) gains included in net income, net of tax	(460)	(19)	73
Change in net cash flow hedges gains, net of tax	337	(997)	(100)
Cash Flow Hedges, Balance at end of period, net of tax	(605)	(942)	55
Benefit plans, Balance at beginning of period, net of tax	(481)	(168)	(302)
Benefit plans, Actuarial gain (loss) arising during the period	96	(415)	159
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	0	0	1
Benefit plans, Actuarial loss arising during the period	96	(415)	160
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax	25	(98)	38
Benefit plans, Net defined benefit pension and other postretirement adjustment arising during the period, net of tax	71	(317)	122
Benefit plans, Amortization of actuarial net loss	36	28	40
Benefit plans, Amortization of prior service (credit) cost	(23)	(23)	(25)
Benefit plans, Total amounts recognized in employee benefits expense	13	5	15
Benefit plans, Less: Provision for income taxes	3	1	3
Benefit plans, Adjustment for amounts recognized as components of net periodic benefit cost during the period, net of tax	10	4	12
Benefit plans, Change in defined benefit pension and other postretirement plans adjustment, net of tax	81	(313)	134
Benefit plans, Balance at end of period, net of tax	(400)	(481)	(168)
Total accumulated other comprehensive loss at end of period, net of tax	$ (3,048)	$ (3,742)	$ (212)