Shareholders' Equity - Accumulated Other Comprehensive Loss, Net of Tax (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ (366)	$ (239)	$ (239)
Other comprehensive income (loss) before reclassifications			(133)	63
Net losses (gains) reclassified from accumulated other comprehensive income			(34)	(22)
Net current period other comprehensive income (loss)			(167)	41
Ending balance	$ (533)	$ (198)	(533)	(198)	(366)	$ (239)
Taxes (benefits)	168	206	420	532
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(187)	(53)	(53)
Other comprehensive income (loss) before reclassifications			(137)	(57)
Net losses (gains) reclassified from accumulated other comprehensive income			0	0
Net current period other comprehensive income (loss)			(137)	(57)
Ending balance	(324)	(110)	(324)	(110)	(187)	(53)
Unrealized Net Gains on Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			49	31	31
Other comprehensive income (loss) before reclassifications			(10)	107
Net losses (gains) reclassified from accumulated other comprehensive income			(26)	(19)
Net current period other comprehensive income (loss)			(36)	88
Ending balance	13	119	13	119	49	31
Taxes (benefits)			8	72	31	18
Unrealized Net Losses on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(99)	(106)	(106)
Other comprehensive income (loss) before reclassifications			11	11
Net losses (gains) reclassified from accumulated other comprehensive income			(8)	(2)
Net current period other comprehensive income (loss)			3	9
Ending balance	(96)	(97)	(96)	(97)	(99)	(106)
Taxes (benefits)			(58)	(63)	(64)	(66)
Recognition of Actuarial Net Loss from Pension and Other Postretirement Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(126)	(110)	(110)
Other comprehensive income (loss) before reclassifications			0	2
Net losses (gains) reclassified from accumulated other comprehensive income			0	(1)
Net current period other comprehensive income (loss)			0	1
Ending balance	(126)	(109)	(126)	(109)	(126)	(110)
Taxes (benefits)			(70)	(61)	(70)	(61)
Accumulated Other Comprehensive Income Attributable to the Non-controlling Interest in VMware, Inc.
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(3)	(1)	(1)
Other comprehensive income (loss) before reclassifications			3	0
Net losses (gains) reclassified from accumulated other comprehensive income			0	0
Net current period other comprehensive income (loss)			3	0
Ending balance	$ 0	$ (1)	$ 0	$ (1)	$ (3)	$ (1)