Shareholders' Equity (Summary Of Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 7,463	$ 7,886	$ 7,353
Other comprehensive loss before reclassifications, net of tax	(3,053)	(359)
Amounts reclassified from AOCI, net of tax	21	(46)
Other comprehensive income (loss), net of tax	(3,032)	(405)	282
Ending balance	4,893	7,463	7,886
Income tax benefit included in other comprehensive loss	(989)	(131)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(80)	325	43
Ending balance	(3,112)	(80)	325
Net unrealized gains (losses) on investment securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(78)	258
Other comprehensive loss before reclassifications, net of tax	(2,722)	(336)
Amounts reclassified from AOCI, net of tax	0	0
Other comprehensive income (loss), net of tax	(2,722)	(336)
Ending balance	(2,800)	(78)	258
Income tax benefit included in other comprehensive loss	(888)	(109)
Net unrealized gains (losses) on derivatives and other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0	69
Other comprehensive loss before reclassifications, net of tax	(332)	(23)
Amounts reclassified from AOCI, net of tax	21	(46)
Other comprehensive income (loss), net of tax	(311)	(69)
Ending balance	(311)	0	69
Income tax benefit included in other comprehensive loss	(101)	(22)
Pension and post-retirement
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2)	(2)
Other comprehensive loss before reclassifications, net of tax	1	0
Amounts reclassified from AOCI, net of tax	0	0
Other comprehensive income (loss), net of tax	1	0
Ending balance	(1)	(2)	$ (2)
Income tax benefit included in other comprehensive loss	$ 0	$ 0