Stockholders' Equity - Additional Information (Detail) $ / shares in Units, shares in Thousands, $ in Millions			1 Months Ended	12 Months Ended
		May 10, 2018 USD ($) shares	Jan. 31, 2019 USD ($)	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 $ / shares shares	Dec. 31, 2002 USD ($) Installment
Accumulated Other Comprehensive Income Loss [Line Items]
Business combination, number of McDermott's shares entitled for each share of CB&I owned	[1]				85,000
Common stock, shares issued				196,000	183,000
Common stock, par value | $ / shares				$ 1.00	$ 1.00
P.T. Sarana Interfab Mandiri [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Percentage of participating interest acquired in subsidiary						25.00%
Option to sell interest | $						$ 5
Series B Warrants [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Warrant issued				90
Series A Preferred Stock [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Preferred stock, shares issued				560
Preferred stock par value | $ / shares				$ 0.001
RSUs [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, unvested				3,000	3,000
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		84,500
Business combination, consideration | $		$ 2,870
Payment during period | $		$ 4,565
Chicago Bridge & Iron Company N.V. [Member] | RSUs [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Stock-settled equity-based awards, restricted stock units, unvested		2,100
Chicago Bridge & Iron Company N.V. [Member] | RSUs [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] | RSUs [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		100
PT McDermott Indonesia [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Common stock, shares issued				11,000
Common stock, par value | $ / shares				$ 1.00
Stock purchase price per share | $ / shares				$ 0.01
Business combination, consideration | $			$ 29
Number of installments payable | Installment						2
Payment during period | $				$ 15
Remaining liability | $				$ 14

[1] As discussed in Note 3, Business Combination, in May 2018, we issued 84.5 million shares of McDermott common stock to the former CB&I shareholders. Additionally, effective as of the Combination Date, unvested and unexercised stock-settled equity-based awards (which included 2.1 million of CB&I restricted stock units and stock options to purchase 0.1 million shares of CB&I’s common stock) were canceled and converted into comparable McDermott stock-settled awards with generally the same terms and conditions as those prior to the Combination Date. The restricted stock units generally vest over a period ranging from three to four years from the original grant date.