Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Goodwill by Reporting Segment (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Balance as of December 31, 2018			$ 2,654	$ 2,654
Adjustments to finalize purchase accounting estimates		$ 107	$ 61	168	[1]
Allocated to APP for disposal				(90)
Currency translation adjustments				(28)
Balance as of June 30, 2019	[2]	$ 2,704		$ 2,704

[1] Includes adjustments of $61 million and $107 million identified in the first and second quarters of 2019, respectively. See Note 3, Business Combination for further discussion.

[2] At June 30, 2019, we had approximately $2.2 billion of cumulative impairment charges recorded in conjunction with our impairment analysis performed during the fourth quarter of 2018, as further described in the 2018 Form 10-K.