Restructuring and Acquisition-Related Charges - Additional information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013 position
Restructuring Cost and Reserve [Line Items]
Restructuring and acquisition-related charges	$ 135	$ 119
Restructuring charges	111	114
Acquisition-related charges	1
Lease termination costs for facilities	6	5
VMware
Restructuring Cost and Reserve [Line Items]
Restructuring charges	22
Acquisition-related charges	1	5
Restructuring 2015 Programs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated		1,320
Restructuring 2015 Programs [Member] | VMware
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 22
Restructuring and Related Cost, Number of Positions Eliminated	350
Restructuring 2014 Programs
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated			1,326