Revenue Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 21,470	$ 17,652	$ 57,893	$ 49,615
United States and Canada
Disaggregation of Revenue [Line Items]
Revenue	9,229	8,026	25,534	22,435
Europe
Disaggregation of Revenue [Line Items]
Revenue	5,055	4,053	13,453	11,774
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue	5,311	3,958	13,893	10,923
Rest of World
Disaggregation of Revenue [Line Items]
Revenue	1,875	1,615	5,013	4,483
United States
Disaggregation of Revenue [Line Items]
Revenue	8,710	7,540	24,100	21,050
Advertising
Disaggregation of Revenue [Line Items]
Revenue	21,221	17,383	56,981	48,919
Other revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 249	$ 269	$ 912	$ 696