Property and Equipment - Components (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Gross property and equipment	$ 68,573	$ 42,441
Total accumulated depreciation	19,707	13,327
Total property and equipment, net	48,866	29,114	$ 21,838
Internal-use software	1,100	1,400
Land and buildings
Property, Plant and Equipment [Line Items]
Gross property and equipment	23,718	13,998
Equipment and internal-use software
Property, Plant and Equipment [Line Items]
Gross property and equipment	38,387	25,989
Other corporate assets
Property, Plant and Equipment [Line Items]
Gross property and equipment	2,390	649
Construction in progress
Property, Plant and Equipment [Line Items]
Gross property and equipment	$ 4,078	$ 1,805