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Long-Term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership. This does not include advances to clients.

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- Definition

Fair value portion of assets classified as held for sale.

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Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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- Definition

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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No definition available.

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- Definition

Present value of lessee's discounted obligation for lease payments from finance lease.

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Amount of lessee's right to use underlying asset under finance lease.

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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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- Definition

Fair value as of the balance sheet date of all derivative assets not designated as hedging instruments.

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Fair value as of the balance sheet date of all derivative liabilities not designated as hedging instruments.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of lessee's right to use underlying asset under operating lease.

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Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets excluding assets held under lease agreements used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Financial Instruments - Summary of Fair Value and Carrying Value of Assets and Liabilities Measured on Recurring and Non-recurring Basis (Details) $ in Thousands	Sep. 30, 2020 USD ($) vessel	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	$ 128,995	$ 96,790	$ 82,483	$ 60,507
Current portion of derivative liabilities (note 8)	755	86
Operating lease right-of-use assets (note 7)	6,148	19,560
At cost, less accumulated depreciation of $496.4 million (2019 - $537.1 million) (note 6)	1,131,742	1,223,085
Vessels related to finance leases, at cost, less accumulated depreciation of $126.9 million (2019 - $143.7 million) (note 7)	484,776	527,081
Short-term Debt	(20,000)	(50,000)
Long-term debt, including current portion (note 6)	(215,065)	(559,679)
Total obligations related to finance leases	(396,072)	(414,788)
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of derivative liabilities (note 8)	755	86
Reported Value Measurement [Member] \| Interest rate swap agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of derivative liabilities (note 8)	(272)	0
Reported Value Measurement [Member] \| Forward freight agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of derivative liabilities (note 8)	(483)	(86)
Fair Value, Recurring [Member] \| Level 1 \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	128,995	95,332
Fair Value, Recurring [Member] \| Level 1 \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	128,995	95,332
Fair Value, Recurring [Member] \| Level 2 \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt	(19,994)	(50,000)
Long-term debt, including current portion (note 6)	(219,271)	(558,657)
Total obligations related to finance leases	(465,342)	(442,648)
Assets Held-for-sale, Long Lived, Fair Value Disclosure	0	37,240
Fair Value, Recurring [Member] \| Level 2 \| Estimate of Fair Value Measurement [Member] \| Interest rate swap agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	989
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value		(659)
Fair Value, Recurring [Member] \| Level 2 \| Estimate of Fair Value Measurement [Member] \| Forward freight agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of derivative liabilities (note 8)	483	86
Fair Value, Recurring [Member] \| Level 2 \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt	(20,000)	(50,000)
Advances to equity-accounted joint venture	5,280	9,930
Long-term debt, including current portion (note 6)	(222,375)	(559,679)
Total obligations related to finance leases	(396,072)	(414,788)
Assets Held-for-sale, Long Lived, Fair Value Disclosure	0	37,240
Fair Value, Recurring [Member] \| Level 2 \| Reported Value Measurement [Member] \| Interest rate swap agreement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value	989
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value		(659)
Fair Value, Recurring [Member] \| Level 2 \| Reported Value Measurement [Member] \| Forward freight agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Current portion of derivative liabilities (note 8)	483	$ 86
Fair Value, Nonrecurring [Member] \| Level 2 \| Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Operating lease right-of-use assets (note 7)	6,148
At cost, less accumulated depreciation of $496.4 million (2019 - $537.1 million) (note 6)	46,750
Vessels related to finance leases, at cost, less accumulated depreciation of $126.9 million (2019 - $143.7 million) (note 7)	34,000
Fair Value, Nonrecurring [Member] \| Level 2 \| Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Operating lease right-of-use assets (note 7)	6,148
At cost, less accumulated depreciation of $496.4 million (2019 - $537.1 million) (note 6)	46,750
Vessels related to finance leases, at cost, less accumulated depreciation of $126.9 million (2019 - $143.7 million) (note 7)	$ 34,000
Property, Plant and Equipment [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Number Of Vessels \| vessel	3
Aframax Tanker
Impaired Long-Lived Assets Held and Used [Line Items]
Number Of Vessels \| vessel	5
Finance Lease Obligations [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Number Of Vessels \| vessel	2