Pension and Postretirement Benefits - Change in Projected Benefit Obligation and Plan Assets (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in plan assets:
Fair value of plan assets at beginning of year		$ 498
Fair value of plan assets at end of year		1,153	$ 498
Pension Plans [Member] | U.S. Pension Plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year		511	505
Acquisition	[1]	16
Interest cost		18	20	$ 21
Actuarial loss (gain)	[2]	(27)	23
Benefits paid		(37)	(37)
Projected benefit obligation at end of year		481	511	505
Change in plan assets:
Fair value of plan assets at beginning of year		497	485
Acquisition	[1]	12
Actual return (loss) on plan assets		(23)	48
Company contributions		1	1
Benefits paid		(37)	(37)
Fair value of plan assets at end of year		450	497	485
Net funded status		(31)	(14)
Amounts recognized in balance sheet consist of:
Prepaid benefit cost within Other non-current assets			1
Accrued benefit cost within accrued liabilities		(2)	(1)
Accrued benefit cost within Other non-current liabilities		(29)	(14)
Net funded status recognized		(31)	(14)
Pension Plans [Member] | Non-U. S. Pension Plans [Member]
Change in projected benefit obligation:
Projected benefit obligation at beginning of year			31
Acquisition	[1]	933
Service cost		8
Interest cost		12	1	1
Actuarial loss (gain)	[2]	(7)	1
Prior service cost	[3]	5
Plan participants' contribution		2
Benefits paid		(27)	(3)
Settlements	[4]		(30)
Currency translation	[5]	(24)
Projected benefit obligation at end of year		902		31
Change in plan assets:
Fair value of plan assets at beginning of year		1	32
Acquisition	[1]	763
Actual return (loss) on plan assets		(23)	2
Company contributions		5
Plan participants' contributions		2
Benefits paid		(25)	(3)
Settlements	[4]		(30)
Currency translation	[5]	(20)
Fair value of plan assets at end of year		703	1	$ 32
Net funded status		(199)	1
Amounts recognized in balance sheet consist of:
Prepaid benefit cost within Other non-current assets		4	1
Accrued benefit cost within accrued liabilities		(2)
Accrued benefit cost within Other non-current liabilities		(201)
Net funded status recognized		(199)	$ 1
Unrecognized net prior service cost (credits)		4
Accumulated other comprehensive loss (income), before taxes	[6]	4
Other Postretirement Plans [Member]
Change in projected benefit obligation:
Acquisition	[1]	31
Interest cost		1
Actuarial loss (gain)	[2]	(1)
Prior service cost	[3]	(11)
Plan participants' contribution		1
Benefits paid		(1)
Projected benefit obligation at end of year		20
Change in plan assets:
Company contributions		1
Benefits paid		(1)
Net funded status		(20)
Amounts recognized in balance sheet consist of:
Accrued benefit cost within accrued liabilities		(2)
Accrued benefit cost within Other non-current liabilities		(18)
Net funded status recognized		(20)
Unrecognized net prior service cost (credits)		(11)
Accumulated other comprehensive loss (income), before taxes	[6]	$ (11)

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

[2] Actuarial gain for 2018 was primarily associated with an increase in discount rate assumptions for a qualified plan in the United States.

[3] Prior service cost for 2018 primarily related to plan changes for our plans in the U.K. and our U.S. retiree welfare plan. Prior service cost for plan changes is deferred to accumulated other comprehensive income and amortized into Other non-operating expense (income).

[4] In August 2017, one of our non-U.S. defined benefit plans was amended to issue lump-sum distributions of certain accrued benefits or allow transfer of such benefits into a defined contribution plan. As of December 31, 2017, all investments in the trust for the defined benefit plan were converted to cash and cash equivalents to facilitate settlements, which were substantially complete. As of December 31, 2018, total benefits remaining under the defined plan were less than $1 million.

[5] The currency translation gain for 2018 was primarily associated with the strengthening of the U.S. Dollar against the currencies associated with our international pension plans, primarily the Euro and British Pound.

[6] During 2019, we expect to recognize approximately $0.2 and $1 million of previously unrecognized net prior service costs and credits, respectively, related to our non-U.S. and other post retirement plans, respectively.