Note 12 - Operating Segment Information (Details Textual) $ in Thousands		1 Months Ended	2 Months Ended	3 Months Ended							10 Months Ended	12 Months Ended
		Nov. 14, 2017 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Nov. 14, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Marine Services Revenue			$ 13,593
Long-Lived Assets	[1]		364,128									$ 364,128
Number of Operating Segments												3
Predecessor [Member]
Marine Services Revenue		$ 13,424		$ 25,805	$ 24,641	$ 24,359	$ 26,617	$ 27,821	$ 30,487	$ 38,794	$ 88,229		$ 123,719	$ 274,806
Long-Lived Assets	[1]						995,220						995,220	1,266,486
UNITED STATES
Marine Services Revenue			3,400
Long-Lived Assets			$ 91,700									$ 91,700
UNITED STATES | Predecessor [Member]
Marine Services Revenue											$ 16,500		28,500	73,400
Long-Lived Assets							$ 371,600						$ 371,600	$ 431,700

[1] Vessels under construction are included in other assets until delivered. Revenue, long-lived assets and capital expenditures presented in the table above are allocated to segments based on the location where the vessel is employed, which in some instances differs from the segment where the vessel is legally owned. For the Successor period from November 15, 2017 through December 31, 2017, we had $3.4 million in revenue and $91.7 million in long-lived assets attributed to the United States, our country of domicile. In the Predecessor period from January 1, 2017 through November 14, 2017, we had $16.5 million in revenue attributed to the United States. In 2016, we had $28.5 million in revenue and $371.6 million in long-lived assets attributed to the United States, our country of domicile. In 2015, we had $73.4 million in revenue and $431.7 million in long-lived assets attributed to the United States.