Investment in Unconsolidated Companies - Additional Information (Detail)		3 Months Ended					4 Months Ended	5 Months Ended			12 Months Ended
		Dec. 31, 2018 USD ($) Vessel Kz / $	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) Vessel Kz / $	Jul. 31, 2017 USD ($) Vessel	Dec. 31, 2017 USD ($) Vessel Kz / $		Dec. 31, 2017 USD ($) Vessel Kz / $	Dec. 31, 2018 USD ($) Vessel Kz / $		Mar. 31, 2017 USD ($) Vessel
Schedule of Equity Method Investments [Line Items]
Fresh-start adjustment equity method investment	[1]						$ (24,683,000)
Fresh-start adjustment, period											10 years
Due from affiliate		$ 132,951,000				$ 230,315,000		$ 230,315,000		$ 230,315,000	$ 132,951,000
Impairments Charges		36,878,000	$ 16,853,000	$ 1,215,000	$ 6,186,000	16,777,000		16,777,000	[2]		61,132,000	[2]
Due to affiliate		34,972,000				99,448,000		99,448,000		99,448,000	34,972,000
Commissions payable	[3]	$ 1,990,000				$ 1,898,000		$ 1,898,000		$ 1,898,000	$ 1,990,000
Number of vessels operating | Vessel		257				227		227		227	257
Total revenues								$ 178,753,000			$ 406,520,000
Investments in, at equity, and advances to unconsolidated companies		$ 1,039,000				$ 29,216,000		29,216,000		$ 29,216,000	1,039,000
DTDW Holdings, Ltd. | NIGERIA
Schedule of Equity Method Investments [Line Items]
Due from related party		23,775,000				33,353,000		33,353,000		33,353,000	23,775,000
Due to related party		$ 5,625,000				9,645,000		9,645,000		9,645,000	$ 5,625,000
Trade and Other Receivables, Net | DTDW Holdings, Ltd. | NIGERIA
Schedule of Equity Method Investments [Line Items]
Due from related party						33,400,000		33,400,000		33,400,000
Accounts Payable | DTDW Holdings, Ltd. | NIGERIA
Schedule of Equity Method Investments [Line Items]
Due to related party						$ 9,600,000		$ 9,600,000		$ 9,600,000
Sonatide Marine, Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership percentage in unconsolidated affiliates		49.00%				49.00%		49.00%		49.00%	49.00%
Fresh-start adjustment equity method investment		$ 27,700,000									$ 27,700,000
Due from affiliate		109,176,000				$ 230,315,000	252,393,000	$ 230,315,000		$ 230,315,000	109,176,000
Due from affiliate current net after offsetting due to affiliate and before Impairment		100,000,000									100,000,000
Cash		58,000,000									58,000,000
Working capital to satisfy net due from affiliate		75,000,000									75,000,000
Impairments Charges											$ 20,000,000
Percentage of devaluation of currency											84.00%
Due to affiliate		29,347,000				99,448,000	$ 123,899,000	99,448,000		99,448,000	$ 29,347,000
Commissions payable		$ 28,000,000									$ 28,000,000
Number of vessels operating | Vessel		4									4
Number of vessels stacked | Vessel		2									2
Investments in, at equity, and advances to unconsolidated companies		$ 0				$ 27,000,000		$ 27,000,000		$ 27,000,000	$ 0
Sonatide Marine, Ltd. | Angola, Kwanza
Schedule of Equity Method Investments [Line Items]
Cash		$ 20,000,000									$ 20,000,000
Foreign currency exchange rate | Kz / $		309				168		168		168	309
Sonatide Marine, Ltd. | Trade Accounts Receivable
Schedule of Equity Method Investments [Line Items]
Net trade accounts receivable		$ 23,000,000									$ 23,000,000
Sonatide Marine, Ltd. | ANGOLA
Schedule of Equity Method Investments [Line Items]
Number of vessels operating | Vessel		37				43	50	43		43	37		58
Number of vessels stacked | Vessel		16				16	21	16		16	16		20
Total revenues							$ 34,000,000			$ 34,000,000	$ 59,000,000		$ 127,000,000
Percentage of Angolan operation revenue							23.00%			20.00%	15.00%		22.00%
DTDW Holdings, Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership percentage in unconsolidated affiliates		40.00%									40.00%
Fresh-start adjustment equity method investment		$ 4,200,000									$ 4,200,000
Sonatide
Schedule of Equity Method Investments [Line Items]
Commissions payable		28,000,000				$ 36,400,000		$ 36,400,000		$ 36,400,000	28,000,000
Investments in, at equity, and advances to unconsolidated companies		$ 0									0
Dividend received											$ 12,000,000
Maximum | Sonatide Marine Ltd and DTDW Holdings Ltd.
Schedule of Equity Method Investments [Line Items]
Ownership percentage in unconsolidated affiliates		50.00%									50.00%

[1] Reflects the adjustment to decrease the carrying value of our equity method investments to their estimated fair values which were determined using a discounted cash flow analysis.

[2] The twelve months ended December 31, 2018, the period August 1, 2017 through December 31, 2017 and the twelve months ended March 31, 2017 included $3.5 million, $2.3 million and $2.2 million respectively, of impairments related to inventory and other non-vessel assets. There were no impairments to non-vessel assets during the period April 1, 2017 through July 31, 2017.

[3] Excludes $28.0 million and $36.4 million of commissions due to Sonatide at December 31, 2018 and 2017, respectively. These amounts are included in amounts due to affiliates.