Segment Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Country	Dec. 31, 2011 Country	Dec. 31, 2010 Country
Segment Reporting Information [Line Items]
Number of broad categories	2
United States
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	3,993.6	3,622.8
International
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	697.9	616.5
Revenues | Geographic risk
Segment Reporting Information [Line Items]
Number of countries, other than United States, that accounted for 10% or more of total revenue	0	0	0
EMC Information Infrastructure
Segment Reporting Information [Line Items]
Number of operating segments	3