Post-Employment and Other Long-Term Employees Benefits - Changes in Benefit Obligation and Plan Assets (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets:
Plan assets at fair value at beginning of year	$ 527
Foreign currency translation adjustments	0	$ 0
Plan assets at fair value at end of year	597	527
Pension Benefits [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	911	936
Service cost	27	27	$ 27
Interest cost	24	24	23
Employee contributions	3	3
Plan amendments	1	1
Benefits paid	(15)	(20)
Effect of curtailment		(1)
Effect of settlement	(36)	(4)
Actuarial (gain) loss	117	(29)
Foreign currency translation adjustment	4	(26)
Benefit obligation at end of year	1,036	911	936
Change in plan assets:
Plan assets at fair value at beginning of year	527	552
Actual return on plan assets	81	(28)
Employer contributions	21	26
Employee contributions	3	3
Benefits paid	(5)	(10)
Effect of settlement	(36)	(4)
Foreign currency translation adjustments	6	(12)
Plan assets at fair value at end of year	597	527	552
Funded status	(439)	(384)
Net amount recognized in the balance sheet consisted of the following:
Non-current assets	4	4
Current liabilities	(10)	(12)
Long-term liabilities	(433)	(376)
Net amount recognized	(439)	(384)
Other Long-Term Benefit [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	81	81
Service cost	5	6	3
Interest cost	1	1	2
Benefits paid	(4)	(3)
Actuarial (gain) loss	6	1
Foreign currency translation adjustment	(1)	(5)
Benefit obligation at end of year	88	81	$ 81
Change in plan assets:
Funded status	(88)	(81)
Net amount recognized in the balance sheet consisted of the following:
Current liabilities	(7)	(6)
Long-term liabilities	(81)	(75)
Net amount recognized	$ (88)	$ (81)

Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.

Name:	us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.