Segment Reporting and Information about Geographic Areas - Schedule of Revenues by Geographic Area (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 10,744	$ 8,771	$ 6,036	$ 5,985	$ 7,384	$ 6,303	$ 6,350	$ 4,541	$ 31,536	$ 24,578	$ 21,461
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									15,207	12,653	14,872
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									6,662	2,979	1,757
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 9,667	$ 8,946	$ 4,832