Summary of Property and Equipment (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Land and land improvements	$ 1,959	$ 1,934
Buildings and leasehold improvements	13,609	13,529
Furniture and equipment	2,383	2,357
Construction in progress	179	106
Property, Plant and Equipment, Gross, Total	18,130	17,926
Less accumulated depreciation and amortization	(8,355)	(8,234)
Property and equipment, net	$ 9,775	$ 9,692

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 of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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Amount before accumulated depreciation of fixtures and equipment. Includes, but is not limited to, machinery, equipment, and engines.

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Amount before accumulated deprecation and depletion of real estate held for productive use and additions or improvements to real estate held for productive use, examples include, but are not limited to, walkways, driveways, fences, and parking lots. Excludes 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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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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