CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Net Income (Loss)	$ (59,047)		$ 54,291		$ (180,866)		$ 173,644
Other comprehensive income (loss), net of tax:
Amortization of benefit plan costs	3,438		2,864		10,308		8,590
Unrealized gain on investments	158		580		599		1,708
Translation adjustments	(1,245)		4,286		(765)		10,725
Unrealized gain (loss) on derivatives	24,770		19,324		(46,270)		(4,779)
Realized loss on derivatives	320		2,978		1,282		5,379
Other comprehensive income (loss), net of tax	27,441	[1]	30,032	[1]	(34,846)	[1]	21,623	[1]
Total Comprehensive Income (Loss)	(31,606)		84,323		(215,712)		195,267
Less: Comprehensive Income Attributable to Noncontrolling Interests.	5,026		3,679		12,050		7,636
Comprehensive Income (Loss) Attributable to McDermott International, Inc.	$ (36,632)		$ 80,644		$ (227,762)		$ 187,631

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