Revenue Recognition - Summary of Revenue by Product Offering, Contract Types and Revenue Recognition Methodology (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	$ 2,289	$ 959	$ 4,632	$ 2,267
Downstream [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1],[2]	860		1,356
Power [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	328		532
Offshore and subsea [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	548	959	1,809	2,267
LNG [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	553		935
Fixed priced [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	1,797	947	3,693	2,209
Hybrid [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	10		134
Reimbursable [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	411		680
Unit-basis and other [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	71	12	125	58
Over time [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	2,249	$ 959	4,564	$ 2,267
At a point in time [Member]
Disaggregation Of Revenue [Line Items]
Revenue Disaggregation	[1]	$ 40		$ 68

[1] Includes the results of our Technology operating group.

[2] Intercompany amounts have been eliminated in consolidation.