Revenues (Revenue by Geographic Location) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 46,173	$ 40,499	$ 125,629	$ 115,782
Hedging gains (losses)	(22)	119	178	364
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	21,442	18,711	58,311	53,106
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	13,924	12,565	38,132	36,546
APAC
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	8,458	6,814	22,641	19,446
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 2,371	$ 2,290	$ 6,367	$ 6,320
Geographic Concentration Risk | Revenue Benchmark
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of total revenue	100.00%	100.00%	100.00%	100.00%
Geographic Concentration Risk | Revenue Benchmark | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of total revenue	47.00%	46.00%	47.00%	46.00%
Geographic Concentration Risk | Revenue Benchmark | EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of total revenue	30.00%	31.00%	30.00%	32.00%
Geographic Concentration Risk | Revenue Benchmark | APAC
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of total revenue	18.00%	17.00%	18.00%	17.00%
Geographic Concentration Risk | Revenue Benchmark | Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of total revenue	5.00%	6.00%	5.00%	5.00%