Stock-Based Compensation - Weighted Average Assumptions Used to Estimate Fair Value of Awards (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
EMC Information Infrastructure Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	34.30%	33.30%	32.90%
Risk-free interest rate	0.80%	1.60%	1.80%
Expected term (in years)	5 years 2 months 12 days	4 years 10 months 24 days	4 years 9 months 18 days
Weighted-average fair value at grant date (in usd per share)	$ 8.56	$ 8.00	$ 6.25
VMware Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	35.80%	37.70%	38.00%
Risk-free interest rate	0.30%	1.00%	1.50%
Expected term (in years)	2 years 8 months 12 days	3 years	3 years 6 months
Weighted-average fair value at grant date (in usd per share)	$ 80.45	$ 88.40	$ 18.05
EMC Employee Stock Purchase - 1989 Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
VMware | VMware Employee Stock Purchase - 2007 Plan | VMware Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%
Expected volatility	37.80%	34.90%	33.10%
Risk-free interest rate	0.10%	0.20%	0.20%
Expected term (in years)	6 months	6 months	6 months
Weighted-average fair value at grant date (in usd per share)	$ 23.36	$ 23.69	$ 15.18