Revenue Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 18,687	$ 16,886	$ 36,423	$ 31,963
United States and Canada
Disaggregation of Revenue [Line Items]
Revenue	8,292	7,632	16,304	14,409
Europe
Disaggregation of Revenue [Line Items]
Revenue	4,249	4,097	8,398	7,721
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue	4,611	3,628	8,582	6,965
Rest of World
Disaggregation of Revenue [Line Items]
Revenue	1,535	1,529	3,139	2,868
United States
Disaggregation of Revenue [Line Items]
Revenue	7,830	7,140	15,380	13,510
Advertising
Disaggregation of Revenue [Line Items]
Revenue	18,321	16,624	35,760	31,536
Other revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 366	$ 262	$ 663	$ 427