Contractual Amounts Due under Leases (Detail) (USD $)	Sep. 30, 2011	Sep. 30, 2010
Leases Disclosure [Line Items]
Due within one year	$ 106,198,000
Due within two years	90,288,000
Due within three years	74,466,000
Thereafter	2,302,000
Total	273,254,000	221,400,000
Less amounts representing interest	(6,362,000)
Present Value	266,892,000
Current portion (included in accounts and notes receivable)	94,111,000
Long-term portion (included in other assets, net)	$ 172,781,000

Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Current

Name:	emc_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPaymentsCurrent
Namespace Prefix:	emc
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Noncurrent

Name:	emc_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPaymentsNoncurrent
Namespace Prefix:	emc
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	emc_LeasesDisclosureLineItems
Namespace Prefix:	emc
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The total of contractually required rental payments on leases meeting the criteria for capitalization.