Segment Reporting and Information about Geographic Areas - Schedule of Long-Lived Assets by Geographic Area (Detail) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 21,548	$ 18,726
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	17,460	15,989
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 4,088	$ 2,737