Restructuring and Acquisition-Related Charges - Additional information (Detail) $ in Millions	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2015 USD ($) position	Mar. 31, 2015 position	Jun. 30, 2014 USD ($) position	Mar. 31, 2014 position	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 position
Restructuring Cost and Reserve [Line Items]
Restructuring and acquisition-related charges	$ 23		$ 30		$ 158	$ 149
Restructuring charges	23		29		133	144
Acquisition-related charges	2		2		3	2
Lease termination costs for facilities	10		4		16	8
VMware
Restructuring Cost and Reserve [Line Items]
Restructuring charges					21
Acquisition-related charges					$ 1	4
Restructuring Reserve, Accrual Adjustment	$ 2		$ 1			$ 1
Restructuring 2015 Programs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated | position	160	1,320
Restructuring 2015 Programs [Member] | VMware
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment	$ (2)
Restructuring and Related Cost, Number of Positions Eliminated | position	350
Restructuring 2014 Programs
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated | position			210	1,320			2,100