Financial Instruments - Additional Information (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2016 USD ($) Vessel	Jan. 31, 2014 shares
Tanker Investments Ltd [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Number of stock purchase warrants		1
Tanker Investments Ltd [Member] \| Maximum [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Number of shares available through exercise of stock purchase warrant (shares)		750,000
Time-charter Swap [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Aframax equivalent vessel percent	55.00%
Aframax equivalent vessels \| Vessel	2
Estimated average daily tanker rate \| $	$ 19
Stock Purchase Warrant [Member] \| Tanker Investments Ltd [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Volatility rate	45.64%

Derivative, Number of Vessel-Equivalents in Swap Agreement

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- Definition

Fair Value Assumptions, Estimated Average Daily Tanker Rate

+ References

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- Definition

Number Of Shares Available Through Exercise Of Stock Purchase Warrant

+ References

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- Definition

Number of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

The percentage of expected requirements covered by the aggregate notional amount of derivative contracts expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract as a percentage of expected need.

+ References

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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