Business Combinations, Intangibles and Goodwill - Goodwill (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Goodwill [Roll Forward]
Balance, beginning of the period	$ 13,840	$ 12,155
Goodwill resulting from acquisitions	172	1,724
Finalization of purchase price allocations and other, net	(18)	(10)
Goodwill transferred in formation of Pivotal	0
Goodwill de-recognized in divestiture of business		(29)
Balance, end of the period	13,994	13,840
Information Storage
Goodwill [Roll Forward]
Balance, beginning of the period	7,442	7,034
Goodwill resulting from acquisitions	9	438
Finalization of purchase price allocations and other, net	(1)	(1)
Goodwill transferred in formation of Pivotal	(112)
Goodwill de-recognized in divestiture of business		(29)
Balance, end of the period	7,338	7,442
Information Intelligence Group
Goodwill [Roll Forward]
Balance, beginning of the period	1,484	1,469
Goodwill resulting from acquisitions	1	15
Finalization of purchase price allocations and other, net	0	0
Goodwill transferred in formation of Pivotal	0
Goodwill de-recognized in divestiture of business		0
Balance, end of the period	1,485	1,484
RSA Information Security
Goodwill [Roll Forward]
Balance, beginning of the period	2,022	1,849
Goodwill resulting from acquisitions	0	179
Finalization of purchase price allocations and other, net	(1)	(6)
Goodwill transferred in formation of Pivotal	0
Goodwill de-recognized in divestiture of business		0
Balance, end of the period	2,021	2,022
Pivotal
Goodwill [Roll Forward]
Balance, beginning of the period	0	0
Goodwill resulting from acquisitions	0	0
Finalization of purchase price allocations and other, net	0	0
Goodwill transferred in formation of Pivotal	140
Goodwill de-recognized in divestiture of business		0
Balance, end of the period	140	0
VMware Virtual Infrastructure Within EMC
Goodwill [Roll Forward]
Balance, beginning of the period	2,892	1,803
Goodwill resulting from acquisitions	162	1,092
Finalization of purchase price allocations and other, net	(16)	(3)
Goodwill transferred in formation of Pivotal	(28)
Goodwill de-recognized in divestiture of business		0
Balance, end of the period	$ 3,010	$ 2,892