Goodwill and Intangible Assets - Intangible Assets (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Total intangible assets, gross	$ 4,547		$ 4,547		$ 4,523
Total intangible assets, net	2,702		2,702		3,246
Amortization expense	195	$ 180	$ 568	$ 539
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			4 years 8 months 13 days
Gross Carrying Amount	4,547		$ 4,547		4,463
Accumulated Amortization	(1,845)		(1,845)		(1,277)
Net Carrying Amount	2,702		2,702		3,186
In-process research and development (IPR&D)
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	0		$ 0		60
Acquired users
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			5 years
Gross Carrying Amount	2,056		$ 2,056		2,056
Accumulated Amortization	(604)		(604)		(382)
Net Carrying Amount	1,452		$ 1,452		1,674
Acquired technology
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			3 years 9 months 19 days
Gross Carrying Amount	915		$ 915		831
Accumulated Amortization	(462)		(462)		(310)
Net Carrying Amount	453		$ 453		521
Acquired patents
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			6 years 1 month 6 days
Gross Carrying Amount	785		$ 785		785
Accumulated Amortization	(399)		(399)		(333)
Net Carrying Amount	386		$ 386		452
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			3 years 4 months 23 days
Gross Carrying Amount	629		$ 629		629
Accumulated Amortization	(265)		(265)		(163)
Net Carrying Amount	364		$ 364		466
Other
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Useful Life (in years)			3 years 6 months 1 day
Gross Carrying Amount	162		$ 162		162
Accumulated Amortization	(115)		(115)		(89)
Net Carrying Amount	$ 47		$ 47		$ 73