Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Debt instrument mandatory commitment reductions and prepayments subject to reinvestment rights with respect to asset sales.

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Decrease in excess cash flow.

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Equity investment ownership percentage.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
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Debt - Additional Information (Detail)					1 Months Ended	3 Months Ended		12 Months Ended
Debt - Additional Information (Detail)	Oct. 30, 2018 USD ($)	May 10, 2018 USD ($)	Apr. 18, 2018 USD ($)	Sep. 30, 2010 USD ($) Installment	Feb. 28, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2018 USD ($)	May 08, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 18, 2017	Dec. 31, 2010
Debt Instrument [Line Items]
Senior secured long-term borrowing									$ 2,260,000,000
Letter of credit facility fee percentage								0.50%
Letter of credit outstanding fronting fee percentage								0.25%
Minimum fixed charge coverage ratio								1.50%
Maximum permitted leverage ratio								4.25%
Debt instrument covenant minimum liquidity								$ 200,000,000
Percentage of interest acquired in subsidiary											53.00%
Future maturities 2019								23,000,000
Future maturities 2020								23,000,000
JRM Mexico [Member]
Debt Instrument [Line Items]
Receivables sold								232,000,000
Factoring costs trade receivables								$ 4,000,000
Percentage of receivables sold withheld and received								10.00%
Cash received from receivables, net of fees and amounts withheld								$ 205,000,000
Loan agreement for equipment financing, term					21 months
Equipment financing amount					$ 47,000,000
Debt instrument, interest rate					5.75%
McDermott International Management [Member]
Debt Instrument [Line Items]
Description of loan agreement								JRM Mexico’s obligations in connection with this equipment financing are guaranteed by McDermott International Management, S. de RL., one of our indirect, wholly owned subsidiaries
Fiscal Quarter Ending on or Before September 30, 2019 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio								4.25%
Fiscal Quarter Ending December 31, 2019 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio								4.00%
Fiscal Quarter Ending After December 31, 2019 and on or Before December 31, 2020 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio								3.75%
Fiscal Quarter Ending After December 31, 2020 and on or Before December 31, 2021 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio								3.50%
Fiscal Quarter Ending after December 31, 2021 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio								3.25%
Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Debt Instrument [Line Items]
Interest rate derivatives									1,940,000,000
Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								4.00%
Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								2.00%
Maximum [Member] \| JRM Mexico [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								2.00%
Maximum [Member] \| Interbank Equilibrium Interest Rate [Member] \| Mexico [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								1.70%
Maximum [Member] \| Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								4.25%
Maximum [Member] \| Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								2.125%
Minimum [Member] \| JRM Mexico [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								1.40%
Minimum [Member] \| Interbank Equilibrium Interest Rate [Member] \| Mexico [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								1.40%
Minimum [Member] \| Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								3.75%
Minimum [Member] \| Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage								1.875%
Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing								$ 1,390,000,000
Available capacity under credit facility								$ 19,000,000
Facility expire month and year								2023-05
Letters of credit outstanding								$ 1,371,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing								1,000,000,000.0
Available capacity under credit facility								$ 889,000,000
Facility expire month and year								2023-05
Borrowing outstanding								$ 0
Maximum borrowing outstanding								110,000,000
Letters of credit outstanding								$ 111,000,000
Revolving Credit Facility [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								4.00%
Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								3.00%
Revolving Credit Facility [Member] \| Maximum [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								4.25%
Revolving Credit Facility [Member] \| Maximum [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								3.25%
Revolving Credit Facility [Member] \| Minimum [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								3.75%
Revolving Credit Facility [Member] \| Minimum [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								2.75%
Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letters of credit outstanding								$ 48,500,000
North Ocean 105 [Member]
Debt Instrument [Line Items]
Percentage of interest acquired in subsidiary												75.00%
Ownership percentage in Oceanteam ASA's							25.00%
Term Facility [Member] \| Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Debt Instrument [Line Items]
Interest rate derivatives									$ 1,940,000,000
Term Facility [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								5.00%
Term Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								4.00%
Term Facility [Member] \| Floor Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								1.00%
Term Facility [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount								$ 2,243,000,000
Second-lien Notes [Member]
Debt Instrument [Line Items]
Aggregate principal amount redeemed								$ 500,000,000
Debt instrument interest rate								8.00%
Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument interest rate			10.625%
Issue of second-lien seven-year senior secured notes			$ 1,300,000,000
Debt instrument maturity month and year			2024-05
Redemption price percentage			100.00%
Senior Notes [Member] \| One or More Qualified Equity Offerings [Member]
Debt Instrument [Line Items]
Redemption price percentage			110.625%
Senior Notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Redemption price percentage			35.00%
Credit Agreement [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing		$ 4,650,000,000
Fees relating to establishment of Credit Agreement		152,000,000
Credit Agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument mandatory commitment reductions and prepayments subject to reinvestment rights with respect to asset sales		500,000,000
Credit Agreement [Member] \| Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing		$ 1,390,000,000
Excess cash flow		75.00%
Decrease in excess cash flow		50.00%
Excess cash flow percentage depending on secured leverage ratio		25.00%
Credit Agreement [Member] \| Term Facility Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit facility fee percentage		3.00%
Credit Agreement [Member] \| Term Facility Letters of Credit [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing								$ 319,300,000
Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing		$ 1,000,000,000.0
Credit Agreement [Member] \| Revolving Credit Facility [Member] \| Maximum [Member] \| Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Avilable credit facility for issuance		200,000,000
Credit Agreement [Member] \| Revolving Credit Facility and Letter of Credit [Member]
Debt Instrument [Line Items]
Fees relating to establishment of Credit Agreement		58,000,000
Credit Agreement [Member] \| Term Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing		$ 2,260,000,000
Term facility maturity period		7 years
Weighted average interest rate								7.27%
Debt instrument periodic payment								$ 5,650,000
Fees relating to establishment of Credit Agreement		$ 94,000,000
Credit Agreement [Member] \| Term Facility [Member] \| Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument issued or deemed issued								276,000,000
Available capacity under credit facility								34,000,000
Credit Agreement [Member] \| Term Facility [Member] \| Financial Letters of Credit
Debt Instrument [Line Items]
Debt instrument issued or deemed issued								$ 71,000,000
Credit Agreement [Member] \| Senior Secured Credit Facility [Member] \| Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Deposited cash collateral account to secure reimbursement obligations		319,300,000
Credit Agreement [Member] \| Senior Secured Credit Facility [Member] \| Term Facility Letters of Credit [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing		$ 310,000,000.0
Credit Agreement [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Fees relating to establishment of Credit Agreement			$ 58,000,000
Debt Instrument Variable Rate Administrative Agent's Prime Rate [Member] \| Term Facility [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								1.00%
Debt Instrument Variable Rate Administrative Agent's Prime Rate [Member] \| Term Facility [Member] \| Federal Funds Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin								0.50%
Letter of Credit Agreement [Member] \| Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Avilable credit facility for issuance								$ 86,000,000
Debt instrument issued or deemed issued								144,000,000
Available capacity under credit facility	$ 230,000,000
Facility expire month and year	2021-12
Fees relating to establishment of Credit Agreement	$ 6,000,000
North Ocean Construction Financing [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount								16,000,000		$ 25,000,000
North Ocean Construction Financing [Member] \| Secured Debt [Member] \| North Ocean 105 [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount								$ 16,000,000
Percentage of interest acquired in subsidiary				75.00%
Debt instrument frequency of installments								semiannual
Number of semiannual installments of principal repayment \| Installment				17
Principal repayment				$ 4,000,000
Debt instrument date of first installment payment				Oct. 01, 2012
Principal repayment, description								The financing agreement requires principal repayment in 17 consecutive semiannual installments of approximately $4 million, which commenced on October 1, 2012.
Ownership percentage in Oceanteam ASA's							25.00%
Purchase of vessel, cash consideration							$ 11,000,000
Note payable assumed							$ 5,000,000
Future maturities 2019								$ 8,000,000
Future maturities 2020								$ 8,000,000
8.000% Second-lien Senior Notes [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount										$ 500,000,000
Aggregate principal amount redeemed						$ 500,000,000
Debt instrument, interest rate						8.00%
Make-whole fees						$ 10,000,000
Write-off of deferred debt issuance costs						$ 4,000,000