Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 39	$ 41	$ 36
Changes due to the Combination	14
Changes due to exchange rate fluctuations	(1)	1
Increases based on tax positions taken in the current year	2	1	2
Increases based on tax positions taken in prior years	9	4	8
Decreases based on tax positions taken in prior years	(5)	(2)	(5)
Decreases due to settlements		(6)
Balance at end of period	$ 58	$ 39	$ 41