Stockholders' Equity - Reconciliation from Basic To Diluted Earnings Per Share for both Numerators and Denominators (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Numerator:
Net income attributable to EMC Corporation	$ 1,147	$ 587	$ 589	$ 392	$ 1,022	$ 586	$ 701	$ 580	$ 2,714	$ 2,889	$ 2,733
Incremental dilution from VMware									7	8	10
Net income – dilution attributable to EMC Corporation									$ 2,707	$ 2,881	$ 2,723
Denominator:
Weighted average shares, basic									2,028	2,074	2,093
Weighted common stock equivalents (in shares)									26	28	40
Assumed conversion of the 2013 Notes and associated warrants (in shares)									5	58	73
Weighted average shares, diluted (in shares)									2,059	2,160	2,206