CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Statement [Abstract]
Revenues	[1]	$ 558,543	$ 805,857	$ 1,994,202	$ 2,402,857
Costs and Expenses:
Cost of operations		455,499	720,961	1,666,974	2,121,942
Selling, general and administrative expenses		46,983	44,664	137,386	144,133
Impairment loss		11,758		44,069	6,808
Loss (gain) on asset disposals		(588)	(100)	(950)	1,443
Restructuring expenses		1,836	6,346	10,687	32,126
Total costs and expenses		515,488	771,871	1,858,166	2,306,452
Operating income	[2]	43,055	33,986	136,036	96,405
Other income (expense):
Interest expense, net		(17,431)	(13,015)	(41,324)	(38,179)
Gain (loss) on foreign currency, net		376	(1,373)	(4,781)	(898)
Other income, net		4,861	1,556	3,776	1,100
Total other expense		(12,194)	(12,832)	(42,329)	(37,977)
Income before provision for income taxes		30,861	21,154	93,707	58,428
Provision for income taxes		15,976	9,094	55,110	30,504
Income before income (loss) from Investments in Unconsolidated Affiliates		14,885	12,060	38,597	27,924
Income (loss) from Investments in Unconsolidated Affiliates		1,507	(4,526)	(2,844)	(18,748)
Net income		16,392	7,534	35,753	9,176
Less: Net income attributable to noncontrolling interest		284	3,868	1,160	8,491
Net income attributable to McDermott International, Inc.		$ 16,108	$ 3,666	$ 34,593	$ 685
Net income attributable to McDermott International, Inc.
Basic:		$ 0.07	$ 0.02	$ 0.14
Diluted:		$ 0.06	$ 0.01	$ 0.12
Shares used in the computation of net income per share:
Basic:		240,899,888	238,594,178	240,093,169	238,128,962
Diluted:		283,907,353	280,797,155	283,132,920	279,025,262

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

[2] The operating results for the nine months ended September 30, 2016 include: (1) a $32 million impairment charge related to the Agile vessel in the AEA segment; and (2) a $12 million impairment charge for certain underutilized marine assets in the ASA segment. The ASA segment’s operating results for the nine months ended September 30, 2015 included a $4 million impairment charge for the DB 101 and $3 million of loss on disposal of this asset.