CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net Loss	$ (29,378)		$ (59,047)		$ (87,926)		$ (180,866)
Other comprehensive income (loss), net of tax:
Amortization of benefit plan costs	3,432		3,438		10,298		10,308
Unrealized gain on investments	(7)		158				599
Translation adjustments	(1,455)		(1,245)		(2,714)		(765)
Gain (loss) on derivatives	(32,930)		25,090		(17,664)		(44,988)
Other comprehensive income (loss), net of tax	(30,960)	[1]	27,441	[1]	(10,080)	[1]	(34,846)	[1]
Total Comprehensive Loss	(60,338)		(31,606)		(98,006)		(215,712)
Less: Comprehensive Income Attributable to Non-controlling Interests	4,290		5,026		6,494		12,050
Comprehensive Loss Attributable to McDermott International, Inc.	$ (64,628)		$ (36,632)		$ (104,500)		$ (227,762)

[1] The tax impacts on amounts presented in other comprehensive income are not significant.