Use of Estimates - Additional Information (Detail) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2017 USD ($)	Dec. 31, 2017 USD ($) Project	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Project
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results	$ 34		$ 91	$ 70
Effect of additional estimated project costs On Income			10
MEA and ASA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results		$ 167
AEA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results			38	27
Partial offset on estimated costs on project		1
AEA [Member] | PB Litoral project [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results			7	12
AEA [Member] | Agile Charter [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Favorable changes due to productivity improvements and cost reduction initiatives				11
AEA [Member] | Other Multiple Projects [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				4
MEA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results		$ 103	38	$ 20
Number of projects | Project		2		2
MEA [Member] | KJO Hout Project [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				$ 9
Loss position in estimated cost of project			8
MEA [Member] | Other Multiple Projects [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				7
MEA [Member] | Abu Ali cable lay project | Project One [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				24
MEA [Member] | ADMA Four GI Project [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Partial offset on estimated costs on project				20
ASA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results		$ 64	15	23
ASA [Member] | Ichthys Project [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results			34
Partial offset on estimated costs on project			31
Effect of additional estimated project costs On Income			$ 10
Benefit from project execution cost saving				5
ASA [Member] | Other Multiple Projects [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				14
ASA [Member] | Gorgon MRU Project [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results				$ 4