Basis of Presentation Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation Basis of Presentation (Policies)	Sep. 30, 2012
Accounting Policies [Abstract]
General	General The accompanying interim consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. These consolidated financial statements include the accounts of EMC, its wholly owned subsidiaries and VMware, a company majority-owned by EMC. All intercompany transactions have been eliminated. Certain information and footnote disclosures normally included in our annual consolidated financial statements have been condensed or omitted. Accordingly, these interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2011 which are contained in our Annual Report on Form 10-K filed with the Securities and Exchange Commission on February 24, 2012. The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for any future period or the entire fiscal year. The interim consolidated financial statements, in the opinion of management, reflect all adjustments necessary to fairly state the results as of and for the three- and nine-month periods ended September 30, 2012 and 2011.
Net Income Per Share	Net Income Per Share Basic net income per weighted average share has been computed using the weighted average number of shares of common stock outstanding during the period. Diluted net income per weighted average share is computed using the weighted average number of common and dilutive common equivalent shares outstanding during the period. Common equivalent shares consist of stock options, restricted stock and restricted stock units, our $1.725 billion 1.75% convertible senior notes due 2013 and associated warrants. Additionally, for purposes of calculating diluted net income per weighted average share, net income is adjusted for the difference between VMware’s reported diluted and basic net income per weighted average share, if any, multiplied by the number of shares of VMware held by EMC.
Adjustments for Immaterial Prior Period Accounting Error	Adjustments for Immaterial Prior Period Accounting Error During the second quarter of 2012, we determined that since VMware’s public offering in 2007, we have incorrectly recorded deferred tax liabilities on the gains and losses associated with changes in the non-controlling interest. These deferred tax liabilities were recorded as a reduction to additional paid-in capital and therefore had no impact on our previously reported consolidated income statements. The error resulted in an overstatement of our deferred tax liability and an understatement of our additional paid-in capital of $352.6 million in our December 31, 2011 consolidated balance sheet and an understatement of additional paid-in capital of $357.2 million in our statement of shareholders’ equity for the nine months ended September 30, 2011. These corrections are reflected in the consolidated balance sheets as of December 31, 2011 and in the statement of shareholders’ equity for the nine months ended September 30, 2011 and are not material to the consolidated balance sheets or statements of shareholders’ equity for the years ended December 31, 2011, 2010, 2009, 2008 or 2007 or any related interim periods. In addition, the error resulted in an overstatement of our deferred tax liability and an understatement of our additional paid-in capital of $467.1 million in our December 31, 2010 consolidated balance sheet and statement of shareholders’ equity and an understatement of additional paid-in capital of $499.6 million in our statement of shareholders’ equity at December 31, 2009. These adjusted prior-period balances will be reflected in our future filings.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In July 2012, the Financial Accounting Standards Board (“FASB”) issued new guidance intended to simplify the impairment testing of indefinite-lived intangible assets other than goodwill. Under this guidance, an entity is allowed to perform a qualitative assessment about the likelihood of impairment of an indefinite-lived intangible asset to determine whether further impairment testing is necessary, similar in approach to the goodwill impairment test. This new guidance is effective for fiscal years beginning after September 15, 2012. We do not believe the adoption of the new guidance will have an impact on our consolidated financial position, results of operations or cash flows. In May 2011, the FASB issued new guidance to achieve common fair value measurement and disclosure requirements between GAAP and International Financial Reporting Standards. This new guidance amends current fair value measurement and disclosure guidance to include increased disclosures regarding valuation inputs and investment categorization. The adoption of this new accounting guidance in 2012 did not have a material impact on our consolidated financial position, results of operations or cash flows.

Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.

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