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Segment Information, Geographical Data and Major Customers (Parenthetical) (Detail) - USD ($) $ in Thousands | 4 Months Ended | 5 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jul. 31, 2017 | Dec. 31, 2017 | Mar. 31, 2017
Segment Reporting Information [Line Items] |  |  |  |
General and administrative expenses |  |  | $ 46,619 |
Predecessor |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
General and administrative expenses |  | $ 41,832 |  | $ 145,879
Corporate Vessels | Construction |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Construction costs |  |  | 9,300 |
Corporate Vessels | Construction | Predecessor |  |  |  |
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
Troms Offshore Supply AS | Corporate | Predecessor |  |  |  |
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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