Goodwill and Other Intangible Assets (Schedule Of Goodwill) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 1,027	$ 1,027
Core deposits and other intangibles, net of accumulated amortization	32	38
Goodwill and intangibles	1,059	1,065
Amegy
Goodwill [Line Items]
Goodwill	615	615
CB&T
Goodwill [Line Items]
Goodwill	379	379
Zions Bank
Goodwill [Line Items]
Goodwill	20	20
Nevada State Bank
Goodwill [Line Items]
Goodwill	$ 13	$ 13