Restricted Stock and Restricted Stock Unit Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
EMC Information Infrastructure | Restricted Stock and Restricted Stock Units
Number of Shares
Outstanding shares - beginning balance	43,377,000	37,363,000	28,902,000
Granted	20,945,000	19,261,000	21,431,000
Vested	(14,832,000)	(11,062,000)	(10,951,000)
Forfeited	(3,959,000)	(2,185,000)	(2,019,000)
Outstanding shares - ending balance	45,531,000	43,377,000	37,363,000
Weighted Average Grant Date Fair Value
Outstanding - weighted average grant date fair value - at beginning of year	$ 17.20	$ 15.01	$ 15.49
Granted	$ 25.12	$ 20.31	$ 14.58
Vested	$ 16.44	$ 15.09	$ 14.83
Forfeited	$ 20.56	$ 15.82	$ 15.56
Outstanding - weighted average grant date fair value - at beginning of year	$ 21.10	$ 17.20	$ 15.01
VMware Virtual Infrastructure Within EMC
Number of Shares
Outstanding shares - beginning balance	9,752,000	9,211,000	7,626,000
Granted	4,548,000	4,933,000	5,200,000
Vested	(3,853,000)	(3,688,000)	(2,881,000)
Forfeited	(907,000)	(704,000)	(734,000)
Outstanding shares - ending balance	9,540,000	9,752,000	9,211,000
Weighted Average Grant Date Fair Value
Outstanding - weighted average grant date fair value - at beginning of year	$ 54.17	$ 33.21	$ 32.35
Granted	$ 91.51	$ 74.87	$ 33.63
Vested	$ 35.00	$ 32.38	$ 31.31
Forfeited	$ 64.70	$ 39.05	$ 34.81
Outstanding - weighted average grant date fair value - at beginning of year	$ 72.74	$ 54.17	$ 33.21