Segment Information - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Country	Dec. 31, 2013 Country
UNITED STATES
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	4,380	4,433
International
Segment Reporting Information [Line Items]
Long-lived assets, excluding financial instruments, deferred tax assets, goodwill and intangible assets	1,021	877
Sales Revenue, Segment | 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
Long-lived Assets, Total | 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
EMC Information Infrastructure
Segment Reporting Information [Line Items]
Number of operating segments	3