CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Revenues	$ 647,250	$ 889,248	$ 1,454,738	$ 1,616,926
Costs and Expenses:
Cost of operations	723,259	759,704	1,436,073	1,357,138
Selling, general and administrative expenses	52,617	47,482	104,843	94,093
(Gain) loss on asset disposals	(13)	29	(14,729)	(197)
Restructuring expenses	15,462		15,462
Total costs and expenses	791,325	807,215	1,541,649	1,451,034
Equity in Loss of Unconsolidated Affiliates	(5,461)	(2,651)	(9,592)	(6,334)
Operating Income (Loss)	(149,536)	79,382	(96,503)	159,558
Other Income (Expense):
Interest income, net	428	1,585	770	3,219
Gain on foreign currency-net	8,904	1,256	6,378	10,697
Other income (expense)-net	(31)	51	751	(530)
Total other income (expense)	9,301	2,892	7,899	13,386
Income (loss) from continuing operations before provision for income taxes and noncontrolling interests	(140,235)	82,274	(88,604)	172,944
Provision for Income Taxes	5,902	28,345	33,215	57,088
Income (loss) from continuing operations before noncontrolling interests	(146,137)	53,929	(121,819)	115,856
Total income from discontinued operations, net of tax				3,497
Net Income (Loss)	(146,137)	53,929	(121,819)	119,353
Less: Net Income Attributable to Noncontrolling Interests	3,286	1,190	7,051	3,856
Net income (loss) attributable to McDermott International, Inc.	$ (149,423)	$ 52,739	$ (128,870)	$ 115,497
Basic:
Income (loss) from continuing operations, less noncontrolling interests	$ (0.63)	$ 0.22	$ (0.55)	$ 0.48
Income from discontinued operations, net of tax				$ 0.01
Net income (loss) attributable to McDermott International, Inc.	$ (0.63)	$ 0.22	$ (0.55)	$ 0.49
Diluted:
Income (loss) from continuing operations, less noncontrolling interests	$ (0.63)	$ 0.22	$ (0.55)	$ 0.47
Income from discontinued operations, net of tax				$ 0.01
Net income (loss) attributable to McDermott International, Inc.	$ (0.63)	$ 0.22	$ (0.55)	$ 0.49
Shares used in the computation of earnings per share:
Basic	236,199,438	235,681,213	236,070,311	235,444,733
Diluted	236,199,438	237,460,765	236,070,311	237,396,697