Acquisitions - Aggregate Allocation of the Purchase Price of Acquisitions to Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 379
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	9 years
All 2014 Acquisitions, excluding Airwatch
Business Acquisition [Line Items]
Intangible assets		$ 484
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		6 years
All 2015 Acquisitions, excluding Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 39
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	3 years 8 months
All 2013 Acquisitions
Business Acquisition [Line Items]
Intangible assets			$ 182
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life			4 years
Purchased technology | Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 302
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	8 years 7 months
Purchased technology | All 2014 Acquisitions, excluding Airwatch
Business Acquisition [Line Items]
Intangible assets		$ 460
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		6 years
Purchased technology | All 2015 Acquisitions, excluding Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 37
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	3 years 8 months
Purchased technology | All 2013 Acquisitions
Business Acquisition [Line Items]
Intangible assets			$ 138
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life			5 years
Customer relationships | All 2014 Acquisitions, excluding Airwatch
Business Acquisition [Line Items]
Intangible assets		$ 10
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		5 years
Customer relationships | All 2013 Acquisitions
Business Acquisition [Line Items]
Intangible assets			$ 34
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life			4 years
Customer relationships and customer lists | Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 50
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	12 years 3 months
Tradename and trademark | Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 27
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	7 years 7 months
Tradename and trademark | All 2014 Acquisitions, excluding Airwatch
Business Acquisition [Line Items]
Intangible assets		$ 14
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		4 years
In-process research and development | All 2013 Acquisitions
Business Acquisition [Line Items]
Intangible assets			$ 10
Noncompete Agreements | All 2015 Acquisitions, excluding Virtustream
Business Acquisition [Line Items]
Intangible assets	$ 2
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life	2 years 1 month
VMware | AirWatch
Business Acquisition [Line Items]
Intangible assets		$ 250
VMware | Purchased technology | AirWatch
Business Acquisition [Line Items]
Intangible assets		$ 118
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		6 years
VMware | Customer relationships and customer lists | AirWatch
Business Acquisition [Line Items]
Intangible assets		$ 78
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		8 years
VMware | Tradename and trademark | AirWatch
Business Acquisition [Line Items]
Intangible assets		$ 40
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		8 years
VMware | Other | AirWatch
Business Acquisition [Line Items]
Intangible assets		$ 14
Finite-Lived Intangible Assets, Net [Abstract]
Weighted-average useful life		3 years