Schedule of Amounts Due from Affiliate (Detail) - USD ($) $ in Thousands		3 Months Ended	4 Months Ended	5 Months Ended	12 Months Ended
		Dec. 31, 2018	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Begining balance					$ 230,315
Less impairment of due from affiliate		$ (20,083)			(20,083)
Ending balance		132,951		$ 230,315	132,951
Sonatide Marine, Ltd.
Schedule of Equity Method Investments [Line Items]
Begining balance				252,393	230,315
Revenue earned by the company through Sonatide				40,303	56,916
Less amounts received from Sonatide				(28,264)	(76,878)
Less amounts used to offset Due to Sonatide obligations	[1]			(33,607)	(78,993)
Less impairment of due from affiliate					(20,083)
Other				(510)	(2,101)
Ending balance		$ 109,176	$ 252,393	230,315	$ 109,176
Predecessor | Sonatide Marine, Ltd.
Schedule of Equity Method Investments [Line Items]
Begining balance			262,652	$ 252,393
Revenue earned by the company through Sonatide			34,397
Less amounts received from Sonatide			(21,019)
Less amounts used to offset Due to Sonatide obligations	[1]		(21,453)
Other			(2,184)
Ending balance			$ 252,393

[1] We reduced the respective due from affiliates and due to affiliates balances each period through netting transactions based on agreement with the joint venture.