Pension and Postretirement Benefits - Change in Projected 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:
Fair value of plan assets at beginning of year		$ 1,153
Fair value of plan assets at end of year		1,267	$ 1,153
Pension Plans [Member] | U.S. Pension Plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year		481	511
Acquisition	[1]		16
Interest cost		19	18	$ 20
Actuarial loss (gain)		40	(27)
Benefits paid		(37)	(37)
Projected benefit obligation at end of year		503	481	511
Change in plan assets:
Fair value of plan assets at beginning of year		450	497
Acquisition	[1]		12
Actual return (loss) on plan assets		78	(23)
Company contributions		1	1
Benefits paid		(37)	(37)
Fair value of plan assets at end of year		492	450	497
Net funded status		(11)	(31)
Amounts recognized in balance sheet consist of:
Prepaid benefit cost within Other non-current assets		9
Accrued benefit cost within accrued liabilities		(1)	(2)
Accrued benefit cost within Other non-current liabilities		(19)	(29)
Net funded status recognized		(11)	(31)
Pension Plans [Member] | Non-U. S. Pension Plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year		902
Acquisition	[1]		933
Service cost		11	8
Interest cost		18	12	1
Actuarial loss (gain)		96	(7)
Prior service cost	[2]		5
Plan participants' contribution		3	2
Benefits paid		(38)	(27)
Currency translation			(24)
Projected benefit obligation at end of year		992	902
Change in plan assets:
Fair value of plan assets at beginning of year		703	1
Acquisition	[1]		763
Actual return (loss) on plan assets		90	(23)
Company contributions		14	5
Plan participants' contributions		3	2
Benefits paid		(38)	(25)
Currency translation		3	(20)
Fair value of plan assets at end of year		775	703	$ 1
Net funded status		(217)	(199)
Amounts recognized in balance sheet consist of:
Prepaid benefit cost within Other non-current assets		9	4
Accrued benefit cost within accrued liabilities		(2)	(2)
Accrued benefit cost within Other non-current liabilities		(224)	(201)
Net funded status recognized		(217)	(199)
Unrecognized net prior service cost (credits)		4	4
Accumulated other comprehensive loss (income), before taxes		4	4
Other Postretirement Plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year		20
Acquisition	[1]		31
Interest cost		1	1
Actuarial loss (gain)		(2)	(1)
Prior service cost	[2]		(11)
Plan participants' contribution			1
Benefits paid		(1)	(1)
Projected benefit obligation at end of year		18	20
Change in plan assets:
Company contributions		1	1
Benefits paid		(1)	(1)
Net funded status		(18)	(20)
Amounts recognized in balance sheet consist of:
Accrued benefit cost within accrued liabilities		(2)	(2)
Accrued benefit cost within Other non-current liabilities		(16)	(18)
Net funded status recognized		(18)	(20)
Unrecognized net prior service cost (credits)		(10)	(11)
Accumulated other comprehensive loss (income), before taxes		$ (10)	$ (11)

[1] Acquisition amounts include the benefit obligation and plan assets at the Combination Date associated with acquired CB&I pension plans.

[2] Prior service cost for 2018 primarily related to plan changes for our plans in the United Kingdom and our U.S. retiree welfare plan. Prior service cost for plan changes is deferred to AOCI and amortized into Other non-operating expense (income).