Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net loss attributable to McDermott International, Inc.	$ (2,172)	$ (14,507)
Weighted average common shares (basic)	239,137,912	237,504,719
Effect of dilutive securities:
Stock options, restricted stock and restricted stock units	40,900,000	40,900,000
Adjusted weighted average common shares and assumed exercises of stock options and vesting of stock awards (diluted)	239,137,912	237,504,719
Net loss attributable to McDermott International, Inc.
Basic:	$ (0.01)	$ (0.06)
Diluted:	$ (0.01)	$ (0.06)