Information about Segments and Geographic Areas (Long-Lived Assets by Geographic Area) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 134,874	$ 123,331
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	101,405	94,907
International
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 33,469	$ 28,424