Information about Segments and Geographic Areas (Long-Lived Assets by Geographic Area) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 96,960	$ 84,587
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	69,315	63,102
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 27,645	$ 21,485