Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues recognized due to changes in transaction price	[1]			$ 8,431	$ 6,705	$ 2,985
Revenue included from settlement of claims		$ 121		121
Advance billings on contracts				1,600
Unapproved change orders and claims		231		231	428
Unapproved change orders and claims in our RPO balance		60		60	130
Incentives amount included in transaction prices		218		218
Incentives amount included in our RPO balance		$ 28		$ 28
Estimated percentage of in progress as of combination date		0.00%		0.00%
Effect of changes in estimated project cost on operating results				$ 700		$ 165
Uncompleted Contracts [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 124		124	266
Cameron Liquefied Natural Gas Project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		45		45
Freeport LNG Train 3 Project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Effect of changes in estimated project cost on operating results				130
NCSA [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues recognized due to changes in transaction price				144
Effect of changes in estimated project cost on operating results				689	190
NCSA [Member] | Cameron Liquefied Natural Gas Project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 45		$ 45
Percentage of complete acquired on post combination basis		87.00%		87.00%
Percentage of complete acquired on pre combination basis		96.00%		96.00%
Effect of changes in estimated project cost on operating results				$ 180
Revenue recognized achievement of progress milestones				200
NCSA [Member] | Freeport LNG Trains 1 and 2 Project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 8		$ 8
Percentage of complete acquired on post combination basis		97.00%		97.00%
Percentage of complete acquired on pre combination basis		99.00%		99.00%
Effect of changes in estimated project cost on operating results				$ 127
Incentive revenues recognized				5
NCSA [Member] | Freeport LNG Train 3 Project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Effect of changes in estimated project cost on operating results				8
NCSA [Member] | Rota 3 pipeline project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 26		26
Effect of changes in estimated project cost on operating results		$ 78	$ 78	$ 78
Percentage of completion		66.00%		66.00%
NCSA [Member] | Asheville power plant project [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 1		$ 1
Effect of changes in estimated project cost on operating results				$ 97
Percentage of completion		98.00%		98.00%
NCSA [Member] | Line 1 and Line 10 project for Pemex [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Provisions for estimated losses		$ 1		$ 1
Effect of changes in estimated project cost on operating results				$ 32
Percentage of completion		99.00%		99.00%
APAC [Member]
Revenue Recognition Multiple Deliverable Arrangements [Line Items]
Revenues recognized due to changes in transaction price					$ 81

[1] Intercompany amounts have been eliminated in consolidation.