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Segment Information, Geographical Data and Major Customers (Parenthetical) (Detail) - USD ($) $ in Thousands | 4 Months Ended | 5 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Jul. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2017 | Mar. 31, 2017
Segment Reporting Information [Line Items] |  |  |  |  |
General and administrative expenses |  |  | $ 46,619 |  |
Corporate Vessels |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Construction costs |  |  |  | $ 9,300 |
Predecessor |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
General and administrative expenses |  | $ 41,832 |  |  | $ 145,879
Predecessor | Corporate Vessels |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
Construction costs |  | 47,500 |  |  | 52,400
Corporate |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
General and administrative expenses | [1] |  | $ 14,823 |  |
Corporate | Predecessor |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
General and administrative expenses | [1] | 17,542 |  |  | 55,389
Corporate | Predecessor | Troms Offshore Supply AS |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |
General and administrative expenses |  | $ 6,700 |  |  | $ 29,000
[1] | Restructuring-related professional services costs for the five month period from August 1, 2017 through December 31, 2017 are included in reorganization items. Included in corporate general and administrative expenses for the period four month period April 1, 2017 through July 31, 2017 (Predecessor) and year ended March 31, 2017 (Predecessor) were $6.7 million and $29 million of restructuring-related professional service costs, respectively.

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- Definition The aggregate costs related to construction and development services during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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- Definition The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.4) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
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