Project Changes in Estimates - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) Project	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results		$ 165	$ 91
NCSA, MENA and APAC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results	$ 29
NCSA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results	190		38
MENA [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results	$ 163	103	38
Number of projects | Project	3
APAC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Effect of changes in estimated project cost on operating results	$ 56	$ 62	$ 17
Number of projects | Project	2