Stock-Based Compensation - Employee Stock Purchase Plan Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
EMC Employee Stock Purchase - 1989 Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash Proceeds	$ 153,698	$ 141,023	$ 120,694
Common shares purchased	7,101	6,899	6,949
Weighted-average price per share	$ 21.65	$ 20.44	$ 17.37
VMware | VMware Employee Stock Purchase - 2007 Plan | VMware Class A common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Cash Proceeds	$ 69,372	$ 56,964	$ 45,162
Common shares purchased	897	816	1,510
Weighted-average price per share	$ 77.34	$ 69.81	$ 29.90