Common stock dividend yield.

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Defined contribution plan matching percent of compensation.

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Share based compensation arrangement by share based payment award, fair value of awards vested.

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Share based compensation arrangements by share based payment award percentage of market price at eligible employees granted options to purchase shares.

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Share based compensation arrangement share based payment award additional shares authorized.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Percentage employer matches of the employee's percentage contribution matched.

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Unrecognized cost of unvested share-based compensation awards.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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-Glossary Financing Activities

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Number of share instruments newly issued under a share-based compensation plan.

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Stock-Based Compensation - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 11, 2002	May 31, 2014	Nov. 12, 1991
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation charges	$ 18,565,000	$ 21,100,000	$ 15,369,000
Unrecognized estimated compensation expense for nonvested awards	26,800,000
Tax benefits realized related to stock options exercised	0	0	0
Tax benefits realized related to restricted stock and restricted stock units	0	0
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized estimated compensation expense for nonvested awards	1,457,000
Common stock dividend yield	0.00%
Total intrinsic value of stock options exercised	900,000	500,000	1,900,000
Cash received from exercise of stock options	600,000	300,000	1,400,000
Weighted-average fair value of stock options granted		$ 4.78	$ 6.93
Fair value of shares vested	4,400,000	3,700,000	3,600,000
2014 McDermott International, Inc. Long-Term Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares authorized for issuance					6,600,000
2009 McDermott International, Inc. Long-Term Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares authorized for issuance	9,000,000
Options to purchase shares, maximum expiration term	7 years
2001 Directors and Officers Long-Term Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options to purchase shares, maximum expiration term	10 years
Percentage of fair market value that options to purchase are granted, minimum	100.00%
Thrift Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares authorized for issuance						15,000,000
Additional shares authorized for issuance				15,000,000
Matching employer contributions percentage of the first 6% of compensation	50.00%
Defined contribution plan matching percent of compensation	6.00%
Common stock issued	0	0	0
Severance and Related Restructuring Costs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation charges	$ 2,000,000