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Asset Impairments - Additional Information (Detail)	1 Months Ended	3 Months Ended						4 Months Ended		5 Months Ended		12 Months Ended
	Jul. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jul. 31, 2017 USD ($) Vessel		Dec. 31, 2017 USD ($) Vessel		Mar. 31, 2017 USD ($) Vessel
Derivatives, Fair Value [Line Items]
Asset impairments		$ 16,777,000								$ 16,777,000	[1]
Number of vessels impaired during the period | Vessel										5
Fair value of assets incurring impairment										$ 8,763,000
Stacked Vessels
Derivatives, Fair Value [Line Items]
Asset impairments										$ 14,400,000
Number of vessels impaired during the period | Vessel										5
Fair value of assets incurring impairment										$ 8,800,000
Active Vessels
Derivatives, Fair Value [Line Items]
Asset impairments										$ 0
Predecessor
Derivatives, Fair Value [Line Items]
Asset impairments	$ 21,325,000		$ 163,423,000	$ 64,857,000	$ 253,422,000	$ 129,562,000	$ 36,886,000	$ 184,748,000	[1]			$ 484,727,000	[1]
Number of vessels impaired during the period | Vessel								79				132
Fair value of assets incurring impairment								$ 571,821,000				$ 933,068,000
Predecessor | Stacked Vessels
Derivatives, Fair Value [Line Items]
Asset impairments								$ 157,800,000
Number of vessels impaired during the period | Vessel								73
Fair value of assets incurring impairment								$ 505,600,000
Predecessor | Active Vessels
Derivatives, Fair Value [Line Items]
Asset impairments								$ 26,900,000
Number of vessels impaired during the period | Vessel								6
Fair value of assets incurring impairment								$ 66,200,000
[1] The period August 1, 2017 through December 31, 2017 and the year ended March 31, 2017 included $2.3 million and $2.2 million, respectively, of impairments related to inventory and other non-vessel assets.

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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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