Restructuring and Acquisition-Related Charges - Additional information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended				9 Months Ended	12 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 VMware	Sep. 30, 2013 VMware	Sep. 30, 2014 VMware	Sep. 30, 2013 VMware	Sep. 30, 2014 Restructuring 2014 Programs position	Jun. 30, 2014 Restructuring 2014 Programs position	Mar. 31, 2014 Restructuring 2014 Programs position	Sep. 30, 2014 Restructuring 2014 Programs VMware position	Sep. 30, 2013 Restructuring 2013 Programs position	Dec. 31, 2013 Restructuring 2013 Programs position	Sep. 30, 2013 Restructuring 2013 Programs VMware	Sep. 30, 2013 Restructuring 2013 Programs VMware	Dec. 31, 2013 Restructuring 2013 Programs VMware position
Restructuring Cost and Reserve [Line Items]
Restructuring and acquisition-related charges	$ 39	$ 40	$ 187	$ 195
Restructuring charges	31	30	175	116		1		54							1	54
Acquisition-related charges	2	4	3	8		1	5	3
Restructuring Reserve, Accrual Adjustment					6		4
Asset Impairment Charges						4		14
Restructuring and Related Cost, Number of Positions Eliminated									241	210	1,326	90	1,525	1,917			710
Lease termination costs for facilities	$ 2	$ 2	$ 10	$ 14