Segment Reporting - Operating Information about Revenues by Geography (Detail) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	[1]	Jun. 30, 2018	[1]	Mar. 31, 2018	[1]	Dec. 31, 2017	[2]	Sep. 30, 2017	[3]	Jun. 30, 2017	[4]	Mar. 31, 2017	[5]	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues	$ 2,073		$ 2,289		$ 1,735		$ 608		$ 718		$ 959		$ 789		$ 519		$ 6,705	$ 2,985	$ 2,636
United States [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	3,695	102	96
Saudi Arabia [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	1,304	1,965	767
Australia [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	253	344	882
Mexico [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	191	143	113
Qatar [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	173	149	420
India [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	144	201	56
United Arab Emirates [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	130	5	54
Denmark [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	118
Oman [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	103
Other countries [Member]
Segment Reporting Revenue Reconciling Item [Line Items]
Revenues																	$ 594	$ 76	$ 248

[1] Results in the second, third and fourth quarters of 2018 reflect impacts of the Combination from the Combination Date.

[2] Operating results for the fourth quarter of 2017 were primarily driven by higher fabrication and marine activity in the MENA segment and installation progress on the Inpex Ichthys project.

[3] Operating results for the third quarter of 2017 reflect high quality operational performance, while operating with peak levels of utilization in the MENA segment and progressing on the Inpex Ichthys project.

[4] Operating results for the second quarter of 2017 continued to reflect efficient project execution and higher engineering, fabrication and marine activity and improved productivity on multiple projects primarily in our MENA segment.

[5] The first quarter of 2017 operating results improvement was driven by strong cost management, with significantly lower project costs in our MENA and APAC segments, and improvements in our selling, general and administrative expenses.