Supplemental Financial Statement Information (Property and Equipment) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 85,258	$ 82,507
Less: accumulated depreciation	(24,730)	(22,788)
Property and equipment, net	60,528	59,719
Land and buildings
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	30,824	30,179
Information technology assets
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	31,551	30,119
Construction in progress
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	17,203	16,838
Leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	5,604	5,310
Furniture and fixtures
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	76	61
Information Technology Assets Held Under Finance Leases
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 835	$ 648

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, 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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