CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net Income (Loss)	$ (146,137)		$ 53,929		$ (121,819)		$ 119,353
Other comprehensive income (loss), net of tax:
Amortization of benefit plan costs	3,215		2,681		6,870		5,726
Unrealized gain on investments	40		431		441		1,128
Translation adjustments	(6,734)		3,326		480		6,439
Unrealized gain (loss) on derivatives	(55,578)		(18,216)		(71,040)		(24,103)
Realized loss on derivatives	3,066		1,107		962		2,401
Other comprehensive income (loss), net of tax	(55,991)	[1]	(10,671)	[1]	(62,287)	[1]	(8,409)	[1]
Total Comprehensive Income (Loss)	(202,128)		43,258		(184,106)		110,944
Less: Comprehensive Income Attributable to Noncontrolling Interests.	3,271		1,138		7,024		3,957
Comprehensive Income (Loss) Attributable to McDermott International, Inc.	$ (205,399)		$ 42,120		$ (191,130)		$ 106,987

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