Summary of Funded Status of Pension Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Benefit Obligation	$ 453	$ 720
Assets for Plan Benefits, Defined Benefit Plan	(24)	0
Liability, Defined Benefit Plan, Current	(3)	(1)
Liability, Defined Benefit Plan, Noncurrent	(186)	(196)
Employee Benefit Plans [Abstract]
Benefit obligation at end of prior year	720	656
Service cost	5	4	$ 5
Interest cost	19	21	22
Actuarial loss	15	115
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	44	(53)
Benefit obligation at end of current year	779	720	656
Fair value of assets at end of prior year	523	527
Actual return on plan assets	59	60
Employer contributions	24	12
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	32	(53)
Net benefits paid	(24)	(23)
Fair value of assets at end of current year	614	523	527
Total unfunded status at end of year (recognized in other non-current liabilities in the Consolidated Balance Sheets)	(165)	(197)
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	264	523
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	30	27	31
Defined Benefit Plan Amortization Of Unrecognized Amounts	8	5	5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	2	3	$ 1
Defined Benefit Plan, Benefit Obligation, Benefits Paid	$ 24	$ 23