Segment Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012 segment	Sep. 30, 2011	Sep. 30, 2012 segment	Sep. 30, 2011	Dec. 31, 2011
Segment Reporting Information [Line Items]
Number of broad categories	2		2
Number of countries other than the US that accounted for 10% or more of total revenues	0	0	0	0
Number of countries other than the US that accounted for 10% or more of total assets			0		0
EMC Information Infrastructure
Segment Reporting Information [Line Items]
Number of operating segments			3
United States
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	3,851.6		3,851.6		3,622.8
International
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	626.8		626.8		616.5