Business Combinations, Intangibles and Goodwill - Goodwill (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Goodwill [Roll Forward]
Balance, beginning of the period	$ 14,424
Goodwill resulting from acquisitions	1,442
Finalization of purchase price allocations and other, net	(7)
Goodwill transferred in acquisition of Pivotal businesses	0
Balance, end of the period	15,859
Information Storage
Goodwill [Roll Forward]
Balance, beginning of the period	7,486
Goodwill resulting from acquisitions	526
Finalization of purchase price allocations and other, net	2
Goodwill transferred in acquisition of Pivotal businesses	6
Balance, end of the period	8,020
Information Intelligence Group
Goodwill [Roll Forward]
Balance, beginning of the period	1,487
Goodwill resulting from acquisitions	0
Finalization of purchase price allocations and other, net	(1)
Goodwill transferred in acquisition of Pivotal businesses	0
Balance, end of the period	1,486
RSA Information Security
Goodwill [Roll Forward]
Balance, beginning of the period	2,203
Goodwill resulting from acquisitions	0
Finalization of purchase price allocations and other, net	0
Goodwill transferred in acquisition of Pivotal businesses	0
Balance, end of the period	2,203
Pivotal
Goodwill [Roll Forward]
Balance, beginning of the period	177
Goodwill resulting from acquisitions	0
Finalization of purchase price allocations and other, net	0
Goodwill transferred in acquisition of Pivotal businesses	(6)
Balance, end of the period	171
VMware Virtual Infrastructure within EMC
Goodwill [Roll Forward]
Balance, beginning of the period	3,071
Goodwill resulting from acquisitions	916
Finalization of purchase price allocations and other, net	(8)
Goodwill transferred in acquisition of Pivotal businesses	0
Balance, end of the period	$ 3,979