Acquisitions, Goodwill, and Acquired Intangible Assets Expected Future Amortization Expense of Acquired Intangible Assets (Detail) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Business Combinations [Abstract]
2017		$ 264
2018		203
2019		170
2020		103
2021		38
Thereafter		76
Acquired Intangibles, Net	[1],[2]	$ 854	$ 992

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

[2] Intangible assets have estimated useful lives of between one and twenty years.