CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenues	$ 1,046,537	$ 476,083	$ 1,597,000	$ 1,079,894
Costs and Expenses:
Cost of operations	925,522	432,298	1,400,981	1,023,791
Selling, general and administrative expenses	47,793	53,444	99,469	105,408
(Gain) loss on disposal of assets	1,910	(35,105)	1,543	(41,544)
Impairment loss (gain)	6,808	(10,664)	6,808	(10,664)
Restructuring expenses	15,391	1,263	25,780	7,388
Total costs and expenses	997,424	441,236	1,534,581	1,084,379
Loss from Investments in Unconsolidated Affiliates	(7,481)	(3,322)	(14,222)	(2,199)
Operating Income (Loss)	41,632	31,525	48,197	(6,684)
Other Income (Expense):
Interest expense, net	(12,985)	(38,745)	(25,164)	(38,684)
Gain on foreign currency, net	1,943	6,622	475	2,540
Other expense, net	(359)	(312)	(456)	(577)
Total other expense	(11,401)	(32,435)	(25,145)	(36,721)
Income (loss) before provision for income taxes and noncontrolling interests	30,231	(910)	23,052	(43,405)
Provision for income taxes	16,541	4,788	21,410	8,277
Net income (loss)	13,690	(5,698)	1,642	(51,682)
Less: net income attributable to noncontrolling interest	2,164	1,699	4,623	2,235
Net income (loss) attributable to McDermott International, Inc.	$ 11,526	$ (7,397)	$ (2,981)	$ (53,917)
Net income (loss) attributable to McDermott International, Inc.:
Basic	$ 0.05	$ (0.03)	$ (0.01)	$ (0.23)
Diluted	$ 0.04	$ (0.03)	$ (0.01)	$ (0.23)
Shares used in the computation of income (loss) per share:
Basic:	238,332,012	237,395,580	237,918,366	237,178,369
Diluted:	289,689,981	237,395,580	237,918,366	237,178,369