Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Schedule of Segment Reporting Information, Revenue by Vessel (Parenthetical) (Detail) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended
	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2018	Jul. 31, 2017	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total revenues		$ 74,300	$ 99,192		$ 296,286
Predecessor
Segment Reporting Information [Line Items]
Total revenues	$ 36,263			$ 312,118
Early Cancellation of Long Term Vessel Charter Contract \| Predecessor \| Americas
Segment Reporting Information [Line Items]
Total revenues				$ 39,100