Equity method investment, cash commitment.

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Equity method investment, final payment towards cash commitment.

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Investment in unconsolidated affiliate related amortization.

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- Definition

Number of liquefied natural gas.

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Number of liquefied natural gas trains.

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Schedule of equity method investments and joint ventures.

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- Definition

Amount of payable due to an entity that is affiliated with the reporting entity by means of direct or indirect ownership. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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Dividends received on equity and other investments during the current period.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Joint Venture and Consortium Arrangements - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($) Train LNG	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Investment in unconsolidated affiliate related amortization		$ 12
Dividends Received		$ 4	$ 0	$ 0
Chevron-Lummus Global [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
NET Power [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		33.30%
Final payment towards cash commitment	$ 10
Cash commitment	57
NET Power [Member] \| McDermott [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Cash commitment	$ 47
McDermott/CTCI [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
io Oil and Gas [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
Qingdao McDermott Wuchuan Offshore Engineering Company Ltd. [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
Accrued Liabilities [Member] \| McDermott/CTCI [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Advances to ventures		$ 95
Accrued Liabilities [Member] \| Proportionately Consolidated Joint Ventures [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Advances to ventures		$ 53
CTCI [Member] \| McDermott/CTCI [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
Exelon [Member] \| NET Power [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		33.30%
8 Rivers Capital [Member] \| NET Power [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		33.30%
Baker Hughes [Member] \| io Oil and Gas [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
Wuhan Wuchuan Investment Holding Co., Ltd. [Member] \| Qingdao McDermott Wuchuan Offshore Engineering Company Ltd. [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Equity method investment, percentage		50.00%
McDermott/Orano [Member] \| McDermott [Member] \| Variable Interest Entities ("VIEs") [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentange in consolidated joint ventures		52.00%
McDermott/Orano [Member] \| Orano [Member] \| Variable Interest Entities ("VIEs") [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentange in consolidated joint ventures		48.00%
McDermott/Zachry [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by parent		50.00%
Number of liquefied natural gas trains \| Train		2
McDermott/Zachry [Member] \| Zachry [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by noncontrolling owners		50.00%
McDermott/Zachry/Chiyoda [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by parent		33.30%
McDermott/Zachry/Chiyoda [Member] \| Zachry [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by noncontrolling owners		33.30%
McDermott/Zachry/Chiyoda [Member] \| Chiyoda [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by noncontrolling owners		33.30%
McDermott/Chiyoda [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by parent		50.00%
Number of Liquefied Natural Gas \| LNG		3
McDermott/Chiyoda [Member] \| Chiyoda [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by noncontrolling owners		50.00%
McDermott/CTCI [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by parent		42.50%
McDermott/CTCI [Member] \| CTCI [Member]
Schedule Of Equity Method Investments And Joint Ventures [Line Items]
Ownership percentage by noncontrolling owners		57.50%