Supplemental Financial Statement Information (Property and Equipment) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 114,292	$ 104,207
Less: accumulated depreciation	(35,544)	(30,561)
Property and equipment, net	78,748	73,646
Land and buildings
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	44,494	39,865
Information technology assets
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	40,731	36,840
Construction in progress
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	21,948	21,036
Leasehold improvements
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	6,922	6,310
Furniture and fixtures
Property, Plant and Equipment, Net [Abstract]
Property and equipment, gross	$ 197	$ 156