Premises and Equipment Summary of Premises and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Land	$ 86	$ 85
Buildings and improvements	818	842
Furniture and equipment	513	492
Total cost	1,417	1,419
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(960)	(944)
Premises and equipment	$ 457	$ 475

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation of building structures held for productive use including addition, improvement, or renovation to the structure, including, but not limited to, interior masonry, interior flooring, electrical, and plumbing.

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Amount before accumulated depreciation of equipment commonly used in offices and stores that have no permanent connection to the structure of a building or utilities. Examples include, but are not limited to, desks, chairs, tables, and bookcases.

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Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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