Accumulated Other Comprehensive Loss (Schedule Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Investment securities, Balance at beginning of period, net of tax		$ (99)	$ 211
Net unrealized losses arising during the period		(1,826)	(184)
Investment securities, Less: Benefit for income taxes		(430)	(43)
Investment securities, Change in net unrealized (losses) gains on investment securities, net of tax		(1,396)	(141)
Investment securities, Balance at end of period, net of tax		(1,495)	70
Cash flow hedges, Balance at beginning of period, net of tax		55	155
Cash flow hedges, Net losses arising during the period		(408)	(16)
Cash flow hedges, Less: Benefit for income taxes		(96)	(4)
Change in net cash flow hedge (losses) gains arising during the period, net of tax		(312)	(12)
Net cash flow hedge gains included in interest and fees on loans		47	48
Cash flow hedges, Less: Provision for income taxes		11	11
Cash flow hedges, reclassification adjustment for net cash flow hedge gains included in net income, net of tax		36	37
Change in net cash flow hedge (losses) gains, net of tax		(348)	(49)
Cash flow hedges, Balance at end of period, net of tax	[1]	(293)	106
Benefit plans, Balance at beginning of period, net of tax		(168)	(302)
Benefit plans, Amortization of actuarial net loss		14	20
Benefit plans, Amortization of prior service credit		(12)	(12)
Benefit plans, Amounts recognized in other noninterest expenses		2	8
Benefit plans, Less: Provision for income taxes		0	2
Benefit plans, Adjustment for amounts recognized as components of net periodic benefit cost during the period, net of tax		2	6
Benefit plans, Change in defined benefit pension and other postretirement plans adjustment, net of tax		2	6
Benefit plans, Balance at end of period, net of tax		(166)	(296)
Total accumulated other comprehensive loss income at end of period, net of tax		$ (1,954)	$ (120)	$ (212)

[1] The Corporation expects to reclassify $112 million of losses, net of tax, from accumulated other comprehensive loss to earnings over the next twelve months if interest yield curves and notional amounts remain at June 30, 2022 levels.