CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	[1]	$ 519,431	$ 729,032
Costs and Expenses:
Cost of operations		428,590	616,002
Research and development expenses		480	31
Selling, general and administrative expenses		36,587	38,328
Other operating (income) expenses		(2,211)	38,678
Total costs and expenses		463,446	693,039
Operating income		55,985	35,993
Other income (expense):
Interest expense, net		(17,706)	(11,238)
Other non-operating income (expense), net		614	(3,391)
Total other expense, net		(17,092)	(14,629)
Income before provision for income taxes		38,893	21,364
Provision for income taxes		10,771	19,330
Income before loss from Investments in Unconsolidated Affiliates		28,122	2,034
Loss from Investments in Unconsolidated Affiliates		(3,927)	(4,478)
Net income (loss)		24,195	(2,444)
Less: Net income (loss) attributable to noncontrolling interest		2,279	(272)
Net income (loss) attributable to McDermott International, Inc.		$ 21,916	$ (2,172)
Net income (loss) per share attributable to McDermott International, Inc.:
Basic		$ 0.09	$ (0.01)
Diluted		$ 0.08	$ (0.01)
Shares used in the computation of net income (loss) per share:
Basic		241,829,988	239,137,912
Diluted		282,285,595	239,137,912

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