CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenues	$ 686,856	$ 1,028,745	$ 2,141,594	$ 2,645,671
Costs and Expenses:
Cost of operations	686,415	889,823	2,122,488	2,246,961
Selling, general and administrative expenses	46,443	51,834	151,286	145,927
Gain on asset disposals	(763)	(85)	(15,492)	(282)
Restructuring charges	4,040		19,502
Total costs and expenses	736,135	941,572	2,277,784	2,392,606
Equity in Loss of Unconsolidated Affiliates	(3,375)	(4,692)	(12,967)	(11,026)
Operating Income (Loss)	(52,654)	82,481	(149,157)	242,039
Other Income :
Interest income, net	363	996	1,133	4,215
Gain on foreign currency-net	4,460	488	10,838	11,185
Other income (expense)-net	1,062	242	1,813	(288)
Total other income	5,885	1,726	13,784	15,112
Income (loss) from continuing operations before provision for income taxes and noncontrolling interests	(46,769)	84,207	(135,373)	257,151
Provision for Income Taxes	12,278	29,916	45,493	87,004
Income (loss) from continuing operations before noncontrolling interests	(59,047)	54,291	(180,866)	170,147
Total income from discontinued operations, net of tax				3,497
Net Income (Loss)	(59,047)	54,291	(180,866)	173,644
Less: Net Income Attributable to Noncontrolling Interests	5,023	3,679	12,074	7,535
Net income (loss) attributable to McDermott International, Inc.	$ (64,070)	$ 50,612	$ (192,940)	$ 166,109
Basic:
Income (loss) from continuing operations, less noncontrolling interests	$ (0.27)	$ 0.21	$ (0.82)	$ 0.69
Income from discontinued operations, net of tax				$ 0.01
Net income (loss) attributable to McDermott International, Inc.	$ (0.27)	$ 0.21	$ (0.82)	$ 0.70
Diluted:
Income (loss) from continuing operations, less noncontrolling interests	$ (0.27)	$ 0.21	$ (0.82)	$ 0.68
Income from discontinued operations, net of tax				$ 0.01
Net income (loss) attributable to McDermott International, Inc.	$ (0.27)	$ 0.21	$ (0.82)	$ 0.69
Shares used in the computation of earnings per share:
Basic	236,257,920	235,817,203	236,132,847	235,568,889
Diluted	236,257,920	237,867,000	236,132,847	237,553,463