Acquisitions, Goodwill, and Acquired Intangible Assets Acquired Intangible Assets (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangibles weighted average life remaining	[1]	3 years 11 months
Acquired Intangibles, Gross	[1],[2]	$ 1,477	$ 1,534
Accumulated Amortization	[1],[2]	(715)	(770)
Acquired Intangibles, Net	[1]	$ 762	764
Marketing-related
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangibles weighted average life remaining		4 years 5 months
Acquired Intangibles, Gross	[2]	$ 457	457
Accumulated Amortization	[2]	(250)	(199)
Acquired Intangibles, Net		$ 207	258
Contract-based
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangibles weighted average life remaining		2 years 1 month
Acquired Intangibles, Gross	[2]	$ 130	172
Accumulated Amortization	[2]	(99)	(125)
Acquired Intangibles, Net		$ 31	47
Technology-based
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangibles weighted average life remaining		3 years 11 months
Acquired Intangibles, Gross	[2]	$ 559	370
Accumulated Amortization	[2]	(205)	(129)
Acquired Intangibles, Net		$ 354	241
Customer-related
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangibles weighted average life remaining		3 years 7 months
Acquired Intangibles, Gross	[2]	$ 331	535
Accumulated Amortization	[2]	(161)	(317)
Acquired Intangibles, Net		$ 170	$ 218
Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		1 year
Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets, estimated useful life		10 years

[1] Intangible assets have estimated useful lives of between one and ten years.

[2] Excludes the original cost and accumulated amortization of fully-amortized intangibles.