Pension And Other Retirement Benefits - Summary of Changes in Benefit Obligations and Fair Value of Plan Assets for Post-Retirement Plans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in benefit obligation:
Interest cost	$ (22)	$ (19)	$ (20)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits liability – current	(7)	(6)
Pension and retirement benefits liability – non current	(299)	(249)
U.S. Plans | Pension Plans
Change in benefit obligation:
Benefit obligation, beginning of the period	(508)	(518)
Service cost	(17)	(19)	(18)
Interest cost	(21)	(17)	(19)
Plan participants’ contributions	0	0
Benefits paid	21	11
Actuarial loss	(3)	0
Assumption changes	(61)	35
Benefit obligation, end of the period	(589)	(508)	(518)
Change in plan assets:
Fair value of plan assets, beginning of the period	348	357
Actual return on plan assets	60	(18)
Benefits paid	(21)	(11)
Employer contributions	8	20
Plan participants’ contributions	0	0
Fair value of plan assets, end of the period	395	348	357
Funded Status of the plans	(194)	(160)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits liability – current	(6)	(5)
Pension and retirement benefits liability – non current	(188)	(155)
Net amount recognized	(194)	(160)
Accumulated benefit obligation, end of the period	(529)	(458)
U.S. Plans | Other Retirement Plans
Change in benefit obligation:
Benefit obligation, beginning of the period	(32)	(31)
Service cost	(3)	(3)	(2)
Interest cost	(1)	(1)	(1)
Plan participants’ contributions	(1)	(1)
Benefits paid	1	1
Actuarial loss	0	0
Assumption changes	(6)	3
Benefit obligation, end of the period	(42)	(32)	(31)
Change in plan assets:
Fair value of plan assets, beginning of the period	0	0
Actual return on plan assets	0	0
Benefits paid	(1)	(1)
Employer contributions	0	0
Plan participants’ contributions	1	1
Fair value of plan assets, end of the period	0	0	$ 0
Funded Status of the plans	(42)	(32)
Amounts recorded on the consolidated balance sheets:
Pension and retirement benefits liability – current	(1)	(1)
Pension and retirement benefits liability – non current	(41)	(31)
Net amount recognized	$ (42)	$ (32)