Stock-Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended					12 Months Ended				12 Months Ended						12 Months Ended							12 Months Ended				12 Months Ended											12 Months Ended						1 Months Ended			12 Months Ended				12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Nov. 30, 2006	Dec. 31, 2011 EMC Information Infrastructure	Dec. 31, 2010 EMC Information Infrastructure	Dec. 31, 2009 EMC Information Infrastructure	Dec. 31, 2008 EMC Information Infrastructure	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Option	Dec. 31, 2010 EMC Information Infrastructure Employee Stock Option	Dec. 31, 2009 EMC Information Infrastructure Employee Stock Option	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock and Restricted Stock Units Performance Based Vesting Condition	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock and Restricted Stock Units If certain performance conditions are achieved	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock and Restricted Stock Units Accelerate upon achieving performance conditions	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock Awards Pro Rata Vesting Minimum	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock Awards Pro Rata Vesting Maximum	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock Awards Cliff Vesting Minimum	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock Awards Cliff Vesting Maximum	May 31, 2007 EMC Information Infrastructure Employee Stock Plan, 2003 Plan	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Maximum	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Employee Stock Option Minimum	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Employee Stock Option Maximum	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Incentive Stock Option Maximum	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Restricted Stock and Restricted Stock Units	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Plan, 2003 Plan Restricted Stock and Restricted Stock Units Minimum	Dec. 31, 2011 EMC Information Infrastructure Employee Stock Purchase Plan, 1989 Plan	Dec. 31, 2011 EMC Information Infrastructure Restricted Stock and Restricted Stock Units	Dec. 31, 2010 EMC Information Infrastructure Restricted Stock and Restricted Stock Units	Dec. 31, 2009 EMC Information Infrastructure Restricted Stock and Restricted Stock Units	Dec. 31, 2008 EMC Information Infrastructure Restricted Stock and Restricted Stock Units	Dec. 31, 2011 EMC Information Infrastructure Stock Incentive Plan 2007	May 31, 2009 EMC Information Infrastructure Stock Incentive Plan 2007	Dec. 31, 2011 VMware	Dec. 31, 2010 VMware	Dec. 31, 2009 VMware	Dec. 31, 2011 VMware Employee Stock Option	Dec. 31, 2010 VMware Employee Stock Option	Dec. 31, 2009 VMware Employee Stock Option	Dec. 31, 2011 VMware Restricted Stock Awards Pro Rata Vesting Minimum	Dec. 31, 2011 VMware Restricted Stock Awards Pro Rata Vesting Maximum	Dec. 31, 2011 VMware Restricted Stock Units and Other Restricted Stock	Jun. 30, 2007 VMware Employee Stock Purchase Plan, 2007 Plan	Dec. 31, 2011 VMware Employee Stock Purchase Plan, 2007 Plan	Dec. 31, 2010 VMware Employee Stock Purchase Plan, 2007 Plan	Dec. 31, 2011 VMware Stock Repurchase Plan	Dec. 31, 2010 VMware Stock Repurchase Plan	Feb. 28, 2011 VMware Stock Repurchase Plan Maximum	Mar. 31, 2010 VMware Stock Repurchase Plan Maximum	Dec. 31, 2011 VMware Stock Incentive Plan 2007 Employee Stock Option	Dec. 31, 2011 VMware Stock Incentive Plan 2007 Employee Stock Option Minimum	Dec. 31, 2011 VMware Stock Incentive Plan 2007 Employee Stock Option Maximum	Dec. 31, 2011 VMware Stock Incentive Plan 2007 Restricted Stock Awards Minimum	Dec. 31, 2011 VMware Stock Incentive Plan 2007 Restricted Stock Awards Maximum	Dec. 31, 2011 VMware Restricted Stock Restricted Stock Units and Other Restricted Stock Restricted Stock Awards	Dec. 31, 2010 VMware Restricted Stock Restricted Stock Units and Other Restricted Stock Restricted Stock Awards	Dec. 31, 2009 VMware Restricted Stock Restricted Stock Units and Other Restricted Stock Restricted Stock Awards	Dec. 31, 2011 VMware Restricted Stock Restricted Stock Units and Other Restricted Stock Restricted Stock Units and Other Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of exercise price compared to fair market value of our common stock																							100.00%					85.00%																85.00%								100.00%
Outstanding shares																													45,531,000	43,377,000	37,363,000	28,902,000																											9,500,000
Percentage of options granted under the plan that vest after the first year																																																			25.00%
Increase in the number of shares available for issuance																																		20,000,000
Common stock reserved for issuance						922,400,000																						153,000,000																6,400,000
Outstanding and unvested, aggregate intrinsic value																													$ 980.7																														$ 793.6
Total number of plans						5
Percentage of exercise price compared to fair market value of our common stock at the time of exercise																																												85.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period																3 years	4 years	3 years	5 years				3 years	5 years			3 years		vest through 2016												3 years	4 years	Scheduled to vest through 2015.								3 years			3 years	4 years
Withholding taxes																																													31.5	24.8
Period in which the option expires																								10 years	10 years																											6 years	7 years
Shares available for grant																					84,200,000	360,000,000											100,000,000
Number of shares converted for every one share issued																										2
Number of plans in addition to the 2003 Plan which the company consolidated into the 2003 Plan																				4
Exercisable, weighted-average remaining contractual term										4.3																												2.5
Exercisable, aggregate intrinsic value										649.5																												508.5
Vested and expected to vest, weighted-average remaining contractual term										5.1																												3.0
Vested and expected to vest, aggregate intrinsic value										868.9																												772.3
Closing stock price					$ 12.61					$ 21.54																												$ 83.19
Cash proceeds from the exercise of stock options										532.4	660.0	251.1																										280.6	386.1	209.4
Pre-tax intrinsic values of options exercised										619.2	470.2	191.6																										647.8	678.8	132.6
Tax benefits realized from the exercise of stock options										126.7	75.3	30.9
Vested total intrinsic values																													371.1	203.7	138.4																									356.1	258.0	88.8
Expected to vest													40,200,000	5,300,000	10,300,000
Options, exercise price per share						$ 13.69	$ 15.23	$ 18.31	$ 19.14
Purchased shares authorized				250,000,000																																													550,000,000	400,000,000
Shares of common stock repurchased	195,800,000																																														6,000,000	4,900,000
Aggregate purchase price	3.7																																														526.2	338.5
Authorized amount remaining for repurchase																																															85.3
Shares of common stock purchased, weighted average purchase price per share						$ 20.44	$ 17.37	$ 11.17																											$ 69.81	$ 29.90	$ 20.14										$ 88.37	$ 68.96
Unrecognized compensation expense	1,059.2
Unrecognized compensation expense recognition period	will be recognized through 2016
Unrecognized compensation expense, weighted average remaining period	1.5
ESPP expense	$ 43.6	$ 34.9	$ 46.9