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Number of shares of equity interests issued or issuable to acquire entity.

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Percentage of voting equity interests acquired at the acquisition date in the business combination.

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Amount of liabilities incurred for goods and services received that are used in an entity's business and related party payables, assumed at the acquisition date.

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The amount by which the company's Total Capital exceeds the minimum required for capital adequacy purposes.

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The fair value of assets acquired in noncash investing or financing activities.

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The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

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Amount of increase (decrease) in the investments in and advances to affiliates.

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Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

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

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Amount of income (expense) related to nonoperating activities, classified as other.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Number of non-vested options outstanding.

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Stockholder's Equity - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions		3 Months Ended		12 Months Ended
	May 10, 2018	Jun. 30, 2017	Sep. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 18, 2017	Dec. 31, 2013	Dec. 31, 2010
Accumulated Other Comprehensive Income Loss [Line Items]
Business combination, number of McDermott's shares entitled for each share of CB&I owned				85.0
Percentage of interest acquired in subsidiary							53.00%
Decrease in noncontrolling interest					$ (8)	$ (18)
Decrease in notes payable				$ 156	(105)	102
Other non-operating expense, net				(56)	$ 5	$ 3
Berlian McDermott Sdn, Bhd, [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Percentage of interest acquired in subsidiary								30.00%
Decrease in noncontrolling interest				$ 18
Fair value of asset surrendered			$ 17
Berlian McDermott Sdn, Bhd, [Member] \| TH Heavy Engineering Berhad [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Noncontrolling interest acquired by noncontrolling owners								30.00%
North Ocean 105 [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Percentage of interest acquired in subsidiary									75.00%
Ownership percentage in Oceanteam ASA's		25.00%
Restricted Stock Units [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, unvested				3.0	2.0
Chicago Bridge & Iron Company N.V. [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Business combination, number of McDermott's shares entitled for each share of CB&I owned	84.5
Purchase of vessel, cash consideration	$ 4,565
Note payable assumed	$ 472
Chicago Bridge & Iron Company N.V. [Member] \| Restricted Stock Units [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, unvested	2.1
Chicago Bridge & Iron Company N.V. [Member] \| Restricted Stock Units [Member] \| Minimum [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, vesting period	3 years
Chicago Bridge & Iron Company N.V. [Member] \| Restricted Stock Units [Member] \| Maximum [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, vesting period	4 years
Chicago Bridge & Iron Company N.V. [Member] \| Stock Options [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, stock options, unvested	0.1
Oceanteam ASA [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Purchase of vessel, cash consideration		$ 11
Note payable assumed		5
Decrease in noncontrolling interest		9
Decrease in notes payable		5
Capital-in-excess		$ 2
THHE Fabricators Sdn. Bhd [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Percentage of interest acquired in subsidiary								30.00%
Decrease in investments in unconsolidated affiliates				$ 12
Other non-operating expense, net				$ 5