CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenues	[1]	$ 805,857	$ 414,595	$ 2,402,857	$ 1,494,489
Costs and Expenses:
Cost of operations		720,961	370,271	2,121,942	1,394,062
Selling, general and administrative expenses		44,664	51,681	144,133	157,089
Loss (gain) on disposal of assets		(100)	(4,818)	1,443	(46,362)
Impairment loss (recovery)				6,808	(10,664)
Restructuring expenses		6,346	4,724	32,126	12,112
Total costs and expenses		771,871	421,858	2,306,452	1,506,237
Loss from Investments in Unconsolidated Affiliates		(4,526)	(3,448)	(18,748)	(5,647)
Operating Income (Loss)	[2]	29,460	(10,711)	77,657	(17,395)
Other Income (Expense):
Interest expense, net		(13,015)	(11,847)	(38,179)	(50,531)
Gain (loss) on foreign currency, net		(1,373)	(2,397)	(898)	143
Other income (expense), net		1,556	473	1,100	(104)
Total other expense		(12,832)	(13,771)	(37,977)	(50,492)
Income (loss) before provision for income taxes and noncontrolling interests		16,628	(24,482)	39,680	(67,887)
Provision for income taxes		9,094	1,464	30,504	9,741
Net income (loss)		7,534	(25,946)	9,176	(77,628)
Less: net income attributable to noncontrolling interest		3,868	4,306	8,491	6,541
Net income (loss) attributable to McDermott International, Inc.		$ 3,666	$ (30,252)	$ 685	$ (84,169)
Net income (loss) attributable to McDermott International, Inc.:
Basic		$ 0.02	$ (0.13)		$ (0.35)
Diluted		$ 0.01	$ (0.13)		$ (0.35)
Shares used in the computation of income (loss) per share:
Basic:		238,594,178	237,429,394	238,128,962	237,262,044
Diluted:		280,797,155	237,429,394	279,025,262	237,262,044

[1] Intersegment transactions included in revenues were not significant for either of the periods presented.

[2] Operating results for the ASA segment included a $4 million impairment charge for the DB101 and $3 million of loss on disposal of this asset in the first and second quarters of 2015, respectively.