Acquisitions (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 16,731	$ 16,468
Other acquisitions
Business Acquisition [Line Items]
Total consideration	312
Cash acquired	12
Acquired intangible assets	111
Goodwill	205
Net liabilities assumed	16
Amount of goodwill expected to be deductible for tax purposes	$ 24
Other acquisitions | Patents and developed technology
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful life	3 years 11 months
Other acquisitions | Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful life	3 years 1 month
Other acquisitions | Trade names and other
Business Acquisition [Line Items]
Acquired intangible assets, weighted-average useful life	8 years 10 months