Information about Segments and Geographic Areas (Long-Lived Assets by Geographic Area) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 62,089	$ 57,347
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	47,383	43,686
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 14,706	$ 13,661