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

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Debt instrument covenant minimum liquidity.

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

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Debt instrument maturity month and year.

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Decrease in excess cash flow.

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Equity investment ownership percentage.

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Excess cash flow percentage.

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Excess cash flow percentage depending on secured leverage ratio.

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Extinguishment of debt make-whole fees.

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Factoring costs trade receivables.

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Letter of credit outstanding fronting fee percentage.

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Letter of credit participation fee percentage.

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Line of credit facility, expiration month and year.

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Long term debt term.

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Maximum permitted leverage ratio.

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Minimum fixed charge coverage ratio.

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Number of semiannual installments of principal repayment.

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Receivables sold.

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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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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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Amount of minimum lease payments for capital leases due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for capital leases due in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Carrying amount as of the balance sheet date of cash collateral held for borrowed securities, for which the cash is restricted as to withdrawal or usage.

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

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Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format.

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

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Description of the frequency of periodic payments (monthly, quarterly, annual).

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The average effective interest rate during the reporting period.

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

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

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Amount of the required periodic payments including both interest and principal payments.

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Amount of the required periodic payments applied to principal.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average interest rate of debt outstanding.

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Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Gross amount of debt extinguished.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Description of long-term debt arrangements, which are debt arrangements that originally require full repayment more than twelve months after issuance or greater than the normal operating cycle of the company, if longer, and disclosures pertaining to the underlying arrangements, including repayment terms, conversion features, interest rates, restrictions on assets and activities, debt covenants, and other matters important to users of the financial statements. Types of long-term debt arrangements include borrowing under notes payable, bonds payable, debentures, term loans, and other contractual obligations for payment.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Debt - Additional Information (Detail)				1 Months Ended	3 Months Ended		6 Months Ended
Debt - Additional Information (Detail)	May 10, 2018 USD ($)	Apr. 18, 2018 USD ($)	Sep. 30, 2010 USD ($) Installment	Feb. 28, 2017 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($)	May 31, 2018 USD ($)	May 08, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 18, 2017
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%		0.25%
Minimum fixed charge coverage ratio							1.50%
Debt instrument covenant minimum liquidity					$ 200,000,000		$ 200,000,000
Percentage of interest acquired in subsidiary											53.00%
Future maturities remainder of 2018					11,000,000		11,000,000
Future maturities 2019					23,000,000		23,000,000
Future maturities 2020					23,000,000		23,000,000
Capital lease					22,000,000		22,000,000	$ 21,000,000		$ 1,000,000
Remainder of 2018					600,000		600,000
2019					1,300,000		1,300,000
2020					1,400,000		1,400,000
2021					1,500,000		1,500,000
2022					1,600,000		1,600,000
Thereafter					$ 14,000,000		14,000,000
JRM Mexico [Member]
Debt Instrument [Line Items]
Base rate and applicable margin					2.00%
Receivables sold					$ 138,700,000
Factoring costs trade receivables					1,900,000
Loan agreement for equipment financing, term				21 months
Equipment financing amount				$ 47,000,000
Debt instrument, interest rate				5.75%
Borrowing outstanding					$ 10,000,000		$ 10,000,000
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%		4.25%
Fiscal Quarter Ending December 31, 2019 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio					4.00%		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%		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%		3.50%
Fiscal Quarter Ending after December 31, 2021 [Member]
Debt Instrument [Line Items]
Maximum permitted leverage ratio					3.25%		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					4.25%		4.25%
Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage					2.125%		2.125%
Maximum [Member] \| Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage					4.25%		4.25%
Maximum [Member] \| Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage					2.125%		2.125%
Minimum [Member] \| Financial Letters of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage					3.75%		3.75%
Minimum [Member] \| Performance Stand By Letters Of Credit [Member]
Debt Instrument [Line Items]
Letter of credit participation fee percentage					1.875%		1.875%
Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing					$ 1,390,000,000		$ 1,390,000,000
Facility expire month and year							2023-05
Letters of credit outstanding					1,377,000,000		$ 1,377,000,000
Available capacity under credit facility					13,000,000,000		13,000,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing					1,000,000,000		$ 1,000,000,000
Facility expire month and year							2023-05
Letters of credit outstanding					121,000,000		$ 121,000,000
Available capacity under credit facility					879,000,000		$ 879,000,000
Revolving Credit Facility [Member] \| Eurodollar Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin							4.25%
Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Base rate and applicable margin							3.25%
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					$ 60,000		$ 60,000
Term Facility [Member]
Debt Instrument [Line Items]
Weighted average interest rate					7.09%		7.09%
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					$ 2,254,000,000		$ 2,254,000,000
Term facility maturity period							7 years
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	150,000,000
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					319,600,000		$ 319,600,000
Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing	$ 1,000,000,000
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	57,000,000
Credit Agreement [Member] \| Term Facility [Member]
Debt Instrument [Line Items]
Senior secured long-term borrowing	2,260,000,000
Debt instrument periodic payment							5,650,000
Fees relating to establishment of Credit Agreement	93,000,000
Credit Agreement [Member] \| Term Facility [Member] \| Letter of Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument issued or deemed issued					308,000,000		$ 308,000,000
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
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%
North Ocean Construction Financing [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount					21,000,000		$ 21,000,000			25,000,000
North Ocean Construction Financing [Member] \| Secured Debt [Member] \| North Ocean 105 [Member]
Debt Instrument [Line Items]
Term facility, borrowings outstanding Amount					21,000,000		$ 21,000,000
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			$ 4,100,000
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 $4.1 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 remainder of 2018					4,000,000		$ 4,000,000
Future maturities 2019					8,000,000		8,000,000
Future maturities 2020					$ 8,000,000		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%		8.00%
Make-whole fees							$ 10,000,000
Write-off of deferred debt issuance costs							$ 4,000,000