Teekay Tankers (TNK) 6-K 22 Nov 19 2019 Q3 Current report (foreign) Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2019
Document And Entity Information [Abstract]
Document Type	6-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Entity Registrant Name	TEEKAY TANKERS LTD.
Entity Central Index Key	0001419945
Current Fiscal Year End Date	--12-31

Unaudited Consolidated Statemen

Unaudited Consolidated Statements of Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
REVENUES
Total revenues	$ 182,304	$ 175,915	$ 617,082	$ 516,039
Voyage expenses (note 14e)	(87,726)	(83,048)	(277,733)	(249,974)
Vessel operating expenses (note 14b)	(48,539)	(52,161)	(156,726)	(157,808)
Time-charter hire expenses (note 8)	(10,637)	(4,317)	(30,877)	(14,697)
Depreciation and amortization	(31,536)	(29,595)	(92,059)	(88,598)
General and administrative expenses (note 14b)	(8,739)	(8,747)	(27,412)	(27,939)
Gain on sale of vessel (note 16)	0	0	0	170
Restructuring charges	0	(213)	0	(1,195)
(Loss) income from operations	(4,873)	(2,166)	32,275	(24,002)
Interest expense	(16,134)	(15,006)	(49,683)	(41,666)
Interest income	138	250	724	568
Realized and unrealized gain (loss) gain on derivative instruments (note 9)	1,453	596	(1,172)	4,725
Equity income (loss) (note 5)	68	(359)	652	265
Freight tax and other tax expenses (note 11)	(1,435)	(2,050)	(5,688)	(10,014)
Other income (note 10)	933	1,251	1,182	6,074
Net loss	$ (19,850)	$ (17,484)	$ (21,710)	$ (64,050)
Per common share amounts (note 15)
- Basic loss per share	$ (0.07)	$ (0.07)	$ (0.08)	$ (0.24)
- Diluted loss per share	$ (0.07)	$ (0.07)	$ (0.08)	$ (0.24)
Weighted-average number of Class A and Class B common stock outstanding (note 15)
- Basic and diluted	268,990,399	268,558,556	268,887,485	268,470,804
Voyage charter revenues
REVENUES
Total revenues	$ 173,034	$ 152,047	$ 576,256	$ 432,017
Time-charter [Member]
REVENUES
Total revenues	1,909	12,326	6,775	51,820
Other revenues
REVENUES
Total revenues	$ 7,361	$ 11,542	$ 34,051	$ 32,202

Unaudited Consolidated Balance

Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current
Cash and cash equivalents	$ 76,705	$ 54,917
Restricted cash – current (note 17)	2,341	2,153
Pool receivable from affiliates, net (note 14d)	562	56,549
Accounts receivable, including affiliate balances of $0.8 million (2018 - $2.1 million) (note 9)	52,245	17,365
Due from affiliates (note 14c)	1,634	39,663
Current portion of derivative assets (note 9)	1,878	2,905
Bunker and lube oil inventory (note 1)	50,473	23,179
Prepaid expenses	14,108	10,917
Other current assets	61,598	17,943
Total current assets	261,544	225,591
Restricted cash – long-term (note 17)	3,437	3,437
At cost, less accumulated depreciation of $551.3 million (2018 - $494.4 million) (note 6)	1,310,541	1,401,551
Vessels related to finance leases, at cost, less accumulated depreciation of $136.1 million (2018 - $111.3 million) (note 8)	525,597	482,010
Operating lease right-of-use assets (notes 2 and 8)	23,595	0
Total vessels and equipment	1,859,733	1,883,561
Investment in and advances to equity-accounted joint venture (note 5)	26,418	25,766
Derivative assets (note 9)	82	2,973
Other non-current assets	910	74
Intangible assets at cost, less accumulated amortization of $12.5 million (2018 - $10.9 million)	9,955	11,625
Goodwill	8,059	8,059
Total assets	2,170,138	2,161,086
Current
Accounts payable, including affiliate balances of $nil (2018 - $0.6 million)	54,824	11,146
Accrued liabilities (note 14c)	46,519	40,856
Short-term debt (note 7)	50,000	0
Due to affiliates (note 14c)	1,241	18,570
Current portion of derivative liabilities (note 9)	0	57
Current portion of long-term debt (note 6)	101,295	106,236
Current obligations related to finance leases (note 8)	24,875	20,896
Current portion of operating lease liabilities (notes 2 and 8)	16,405	0
Other current liabilities	255	0
Total current liabilities	295,414	197,761
Long-term debt (note 6)	507,665	629,170
Long-term obligations related to finance leases (note 8)	396,059	354,393
Long-term operating lease liabilities (notes 2 and 8)	7,190	0
Other long-term liabilities (note 11)	37,474	32,829
Derivative liabilities (note 9)	49	0
Total liabilities	1,243,851	1,214,153
Equity
Common stock and additional paid-in capital (585.0 million shares authorized, 232.0 million Class A and 37.0 million Class B shares issued and outstanding as of September 30, 2019 and 585.0 million shares authorized, 231.6 million Class A and 37.0 million Class B shares issued and outstanding as of December 31, 2018) (note 13)	1,296,993	1,295,929
Accumulated deficit	(370,706)	(348,996)
Total equity	926,287	946,933
Total liabilities and equity	$ 2,170,138	$ 2,161,086

Unaudited Consolidated Balanc_2

Unaudited Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Accounts receivable, related parties, current	$ 0.8	$ 2.1
Accumulated depreciation on vessels and equipment	551.3	494.4
Finance Leases, Lessee Balance Sheet Assets by Major Class Accumulated Deprecation	136.1	111.3
Accounts Payable, Related Parties, Current	0	0.6
Accumulated amortization on intangible assets	$ 12.5	$ 10.9
Common stock, shares authorized (in shares)	585,000,000	585,000,000
Class A
Common stock, shares authorized (in shares)	485,000,000	485,000,000
Common stock, shares issued (in shares)	232,000,000	231,600,000
Common stock, shares outstanding (in shares)	232,000,000	231,600,000
Class B
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	37,000,000	37,000,000
Common stock, shares outstanding (in shares)	37,000,000	37,000,000

Unaudited Consolidated Statem_2

Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net loss	$ (21,710)	$ (64,050)
Non-cash items:
Depreciation and amortization	92,059	88,598
Gain on sale of vessel (note 16)	0	(170)
Unrealized loss (gain) on derivative instruments (note 9)	3,960	(3,287)
Equity income (note 5)	(652)	(265)
Freight tax expense (note 11)	4,181	3,859
Other	3,690	4,307
Change in operating assets and liabilities	18,685	(17,402)
Expenditures for dry docking	(37,430)	(17,035)
Net operating cash flow	62,783	(5,445)
FINANCING ACTIVITIES
Proceeds from long-term debt, net of issuance costs	56,788	46,128
Scheduled repayments of long-term debt	(76,216)	(92,380)
Prepayments of long-term debt	(109,688)	(102,717)
Prepayments of Short-Term Debt	(75,000)	0
Proceeds from financing related to sales and leaseback of vessels (note 8)	63,720	156,644
Scheduled repayments of obligations related to finance leases (note 8)	(18,075)	(8,841)
Cash dividends paid	0	(8,052)
Other	(126)	(92)
Proceeds from short-term debt (note 7)	125,000	0
Net financing cash flow	(33,597)	(9,310)
INVESTING ACTIVITIES
Proceeds from sale of vessel (note 16)	0	589
Expenditures for vessels and equipment	(7,210)	(3,463)
Return of capital from equity-accounted for joint venture	0	746
Net investing cash flow	(7,210)	(2,128)
Increase (decrease) in cash, cash equivalents and restricted cash	21,976	(16,883)
Cash, cash equivalents and restricted cash, beginning of the period	60,507	75,710
Cash, cash equivalents and restricted cash, end of the period	$ 82,483	$ 58,827

Unaudited Consolidated Statem_3

Unaudited Consolidated Statement of Changes in Equity - USD ($) shares in Thousands, $ in Thousands	Total	Class A	Class B	Common Stock and Additional Paid-in Capital	Common Stock and Additional Paid-in CapitalClass A	Common Stock and Additional Paid-in CapitalClass B	Accumulated Deficit
Common Stock, Dividends, Per Share, Declared	$ 0.03
Balance at beginning of period at Dec. 31, 2017	$ 1,006,601				$ 1,206,466	$ 88,532	$ (288,397)
Balance at beginning of period (shares) at Dec. 31, 2017				268,202
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(19,153)						(19,153)
Dividends declared ($0.03 per share)	(8,052)						(8,052)
Stock Issued During Period, Shares, Employee Benefit Plan				357
Equity-based compensation (note 13)	613				613
Other	(274)				(274)
Balance at end of period at Mar. 31, 2018	979,735				1,206,805	88,532	(315,602)
Balance at end of period (shares) at Mar. 31, 2018				268,559
Balance at beginning of period at Dec. 31, 2017	1,006,601				1,206,466	88,532	(288,397)
Balance at beginning of period (shares) at Dec. 31, 2017				268,202
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(64,050)
Balance at end of period at Sep. 30, 2018	935,211				1,207,177	88,532	(360,498)
Balance at end of period (shares) at Sep. 30, 2018				268,559
Balance at beginning of period at Mar. 31, 2018	979,735				1,206,805	88,532	(315,602)
Balance at beginning of period (shares) at Mar. 31, 2018				268,559
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(27,413)						(27,413)
Equity-based compensation (note 13)	148				148
Balance at end of period at Jun. 30, 2018	952,470				1,206,953	88,532	(343,015)
Balance at end of period (shares) at Jun. 30, 2018				268,559
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(17,484)						(17,484)
Equity-based compensation (note 13)	224				224
Other	(1)						1
Balance at end of period at Sep. 30, 2018	935,211				1,207,177	88,532	(360,498)
Balance at end of period (shares) at Sep. 30, 2018				268,559
Balance at beginning of period at Dec. 31, 2018	946,933				1,207,397	88,532	(348,996)
Balance at beginning of period (shares) at Dec. 31, 2018		231,600	37,000	268,559
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	12,447						12,447
Stock Issued During Period, Shares, Employee Benefit Plan				431
Equity-based compensation (note 13)	668				668
Balance at end of period at Mar. 31, 2019	960,048				1,208,065	88,532	(336,549)
Balance at end of period (shares) at Mar. 31, 2019				268,990
Balance at beginning of period at Dec. 31, 2018	946,933				1,207,397	88,532	(348,996)
Balance at beginning of period (shares) at Dec. 31, 2018		231,600	37,000	268,559
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(21,710)
Balance at end of period at Sep. 30, 2019	926,287				1,208,461	88,532	(370,706)
Balance at end of period (shares) at Sep. 30, 2019		232,000	37,000	268,990
Balance at beginning of period at Mar. 31, 2019	960,048				1,208,065	88,532	(336,549)
Balance at beginning of period (shares) at Mar. 31, 2019				268,990
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(14,307)						(14,307)
Stock Issued During Period, Shares, Employee Benefit Plan				0
Equity-based compensation (note 13)	154				154
Balance at end of period at Jun. 30, 2019	945,895				1,208,219	88,532	(350,856)
Balance at end of period (shares) at Jun. 30, 2019				268,990
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(19,850)						(19,850)
Equity-based compensation (note 13)	242				242
Balance at end of period at Sep. 30, 2019	$ 926,287				$ 1,208,461	$ 88,532	$ (370,706)
Balance at end of period (shares) at Sep. 30, 2019		232,000	37,000	268,990

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The unaudited interim consolidated financial statements (or consolidated financial statements ) have been prepared in accordance with United States generally accepted accounting principles (or GAAP ). These consolidated financial statements include the accounts of Teekay Tankers Ltd., its wholly-owned subsidiaries, equity-accounted joint venture and any variable interest entities (or VIEs ) of which it is the primary beneficiary (collectively, the Company ). The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Certain information and footnote disclosures required by GAAP for complete annual financial statements have been omitted and, therefore, these consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2018 , filed on Form 20-F with the U.S. Securities and Exchange Commission (or the SEC ) on April 10, 2019. In the opinion of management, these consolidated financial statements reflect all adjustments, consisting solely of a normal recurring nature, necessary to present fairly, in all material respects, the Company’s consolidated financial position, results of operations, and cash flows for the interim periods presented. The results of operations for the interim periods presented are not necessarily indicative of those for a full fiscal year. Intercompany balances and transactions have been eliminated upon consolidation. Effective March 31, 2019 , the Company separately presents bunker and lube oil inventory on the Company’s consolidated balance sheet. Such amounts were previously classified as prepaid expenses. Bunker and lube oil inventory increased significantly as of the first quarter of 2019, as a result of changes to the Company’s revenue sharing arrangements (or RSAs ) whereby the Company now directly procures and has legal title to the bunker fuel for the vessels in the RSAs, with such assets being used as collateral for the new working capital loan arrangement entered into by the Company. Bunker and lube oil inventory is stated at cost, which is determined on a first-in, first-out basis. Comparative figures have been reclassified to conform to the presentation adopted in the current period.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncement In February 2016, the Financial Accounting Standards Board (or FASB ) issued Accounting Standards Update 2016-02, Leases (or ASU 2016-02 ). ASU 2016-02 established a right-of-use model that requires a lessee to record a right-of-use asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. For lessees, leases are classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. ASU 2016-02 requires lessors to classify leases as a sales-type, direct financing, or operating lease. A lease is a sales-type lease if any one of five criteria are met, each of which indicate that the lease, in effect, transfers control of the underlying asset to the lessee. If none of those five criteria are met, but two additional criteria are both met, indicating that the lessor has transferred substantially all of the risks and benefits of the underlying asset to the lessee and a third party, the lease is a direct financing lease. All leases that are not sales-type leases or direct financing leases are operating leases. FASB issued an additional accounting standards update in July 2018 that made further amendments to accounting for leases, including allowing the use of a transition approach whereby a cumulative effect adjustment is made as of the effective date, with no retrospective effect and providing an optional practical expedient to lessors to not separate lease and non-lease components of a contract if certain criteria are met. The Company adopted ASU 2016-02 on January 1, 2019 and has elected to use this new optional transition approach. To determine the cumulative effect adjustment, the Company has not reassessed lease classification, initial direct costs for any existing leases and whether any expired or existing contracts are or contain leases. The adoption of ASU 2016-02 has resulted in a change in accounting method for the lease portion of the daily charter hire for the Company’s chartered-in vessels accounted for as operating leases with firm periods of greater than one year as well as a small number of office leases. The Company’s time charters and voyage charters include both a lease component, consisting of the lease of the vessel, and non-lease component, consisting of operation of the vessel for the customer. The Company has elected not to separate the non-lease component from the lease component for all such charters, where the lease component is classified as an operating lease, and account for the combined component as an operating lease. The Company identified the following differences: • Under ASU 2016-02, the Company recognizes an operating lease right-of-use asset and an operating lease liability on the balance sheet for these chartered-in vessels and office leases based on the present value of future minimum lease payments, whereas previously no right-of-use asset or lease liability was recognized. As a result, operating lease right-of-use assets and operating lease liabilities of $ 11.0 million were each recognized on January 1, 2019. The pattern of expense recognition of chartered-in vessels has remained unchanged, unless the right-of-use asset becomes impaired. • The adoption of ASU 2016-02 results in sale and leaseback transactions where the seller lessee has a fixed price repurchase option, or other situations where the leaseback would be classified as a finance lease, being accounted for as a failed sale of the vessel and a failed purchase of the vessel by the buyer lessor. Prior to the adoption of ASU 2016-02, such transactions were accounted for as a completed sale and a completed purchase. Consequently, for such transactions, the Company does not derecognize the vessel sold and continues to depreciate the vessel as if it was the legal owner. Proceeds received from the sale of the vessel are recognized as an obligation related to finance lease, and bareboat charter hire payments made by the Company to the lessor are allocated between interest expense and principal repayments on the obligation related to finance lease. The adoption of ASU 2016-02 has resulted in the sale and leaseback of the Aspen Spirit and Cascade Spirit during the second quarter of 2019 being accounted for as a failed sale and unlike the 14 sale-leaseback transactions entered into in prior years, the Company is not considered as holding a variable interest in the buyer lessor entity and, thus, does not consolidate the buyer lessor entities (see note 8).

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	Revenue The Company’s primary source of revenue is from chartering its vessels (Aframax tankers, Suezmax tankers and Long Range 2 (or LR2 ) tankers) to its customers. The Company utilizes two primary forms of contracts, consisting of voyage charters and time-charters. The extent to which the Company employs its vessels on voyage charters versus time charters is dependent upon the Company’s chartering strategy and the availability of time charters. Spot market rates for voyage charters, including conventional voyages and lightering voyages, are volatile from period to period, whereas time charters provide a stable source of monthly revenu e. The Company also provides ship-to-ship support services, which include managing the process of transferring cargo between seagoing ships positioned alongside each other, either stationary or underway, as well as commercial management services to third-party owners of vessels. Finally, the Company manages liquefied natural gas (or LNG ) terminals and procures LNG-related goods for terminal owners and other customers. For descriptions of these types of contracts, see Item 18 - Financial Statements: Note 3 in the Company’s audited consolidated financial statements filed with its Annual Report on Form 20-F for the year ended December 31, 2018 . The following table contains a breakdown of the Company's revenue by contract type for the three and nine months ended September 30, 2019 and September 30, 2018 . All revenue is part of the Company's conventional tanker segment , except for revenue for ship-to-ship support services and LNG terminal management, consultancy, procurement and other related services, which are part of the Company's ship-to-ship transfer segment. The Company’s lease income consists of the revenue from its voyage charters and time-charters. Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 $ $ $ $ Voyage charter revenues Suezmax 85,523 90,267 268,972 243,771 Aframax 51,075 29,210 164,381 76,952 LR2 23,989 16,712 84,001 40,312 Full service lightering 12,447 15,858 58,902 70,982 Total 173,034 152,047 576,256 432,017 Time-charter revenues Aframax — 7,784 1,837 31,608 Suezmax 1,909 2,909 4,938 13,063 LR2 — 1,633 — 7,149 Total 1,909 12,326 6,775 51,820 Other revenues Ship-to-ship support services 4,649 8,217 17,810 22,452 Commercial management 1,893 2,050 6,219 6,246 LNG terminal management, consultancy, procurement and other 819 1,275 10,022 3,504 Total 7,361 11,542 34,051 32,202 Total revenues 182,304 175,915 617,082 516,039 Charters-out As at September 30, 2019 , one ( December 31, 2018 - two ) of the Company’s vessels operated under a fixed-rate time charter contract, which is scheduled to expire in 2020. As at September 30, 2019 , the minimum scheduled future revenues to be received by the Company under this time charter were approximately $6.3 million ( December 31, 2018 - $6.3 million ).

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting The Company has two reportable segments, its conventional tanker segment and its ship-to-ship transfer segment. The Company’s conventional tanker segment consists of the operation and commercial management of all of its tankers and those tankers employed on full service lightering contracts. The Company’s ship-to-ship transfer segment consists of the Company’s ship-to-ship support services, including those provided to the Company’s conventional tanker segment as part of full service lightering operations and LNG terminal management, consultancy, procurement and other related services. Segment results are evaluated based on (loss) income from operations. The accounting policies applied to the reportable segments are the same as those used in the preparation of the Company’s consolidated financial statements. The following tables include results for the Company’s revenues and (loss) income from operations by segment for the three and nine months ended September 30, 2019 and September 30, 2018 . Three Months Ended September 30, 2019 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 176,836 8,685 (3,217 ) 182,304 Voyage expenses (90,943 ) — 3,217 (87,726 ) Vessel operating expenses (41,833 ) (6,706 ) — (48,539 ) Time-charter hire expenses (9,331 ) (1,306 ) — (10,637 ) Depreciation and amortization (30,634 ) (902 ) — (31,536 ) General and administrative expenses (3) (7,955 ) (784 ) — (8,739 ) Loss from operations (3,860 ) (1,013 ) — (4,873 ) Equity income 68 — — 68 Three Months Ended September 30, 2018 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 166,423 12,019 (2,527 ) 175,915 Voyage expenses (85,575 ) — 2,527 (83,048 ) Vessel operating expenses (43,432 ) (8,729 ) — (52,161 ) Time-charter hire expenses (2,935 ) (1,382 ) — (4,317 ) Depreciation and amortization (28,532 ) (1,063 ) — (29,595 ) General and administrative expenses (3) (7,985 ) (762 ) — (8,747 ) Restructuring charges — (213 ) — (213 ) Loss from operations (2,036 ) (130 ) — (2,166 ) Equity loss (359 ) — — (359 ) Nine Months Ended September 30, 2019 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 589,250 36,421 (8,589 ) 617,082 Voyage expenses (286,322 ) — 8,589 (277,733 ) Vessel operating expenses (129,555 ) (27,171 ) — (156,726 ) Time-charter hire expenses (26,497 ) (4,380 ) — (30,877 ) Depreciation and amortization (89,422 ) (2,637 ) — (92,059 ) General and administrative expenses (3) (25,030 ) (2,382 ) — (27,412 ) Income (loss) from operations 32,424 (149 ) — 32,275 Equity income 652 — — 652 Nine Months Ended September 30, 2018 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 490,083 35,061 (9,105 ) 516,039 Voyage expenses (259,079 ) — 9,105 (249,974 ) Vessel operating expenses (131,886 ) (25,922 ) — (157,808 ) Time-charter hire expenses (10,326 ) (4,371 ) — (14,697 ) Depreciation and amortization (85,171 ) (3,427 ) — (88,598 ) General and administrative expenses (3) (25,385 ) (2,554 ) — (27,939 ) Gain on sale of vessel — 170 — 170 Restructuring charges (152 ) (1,043 ) — (1,195 ) Loss from operations (21,916 ) (2,086 ) — (24,002 ) Equity income 265 — — 265 (1) The ship-to-ship transfer segment provides lightering support services to the conventional tanker segment for full service lightering operations and the pricing for such services was based on actual costs incurred. (2) Revenues, net of the inter-segment adjustment, earned from the ship-to-ship transfer segment are reflected in Other Revenues in the Company's consolidated statements of loss. (3) Includes direct general and administrative expenses and indirect general and administrative expenses (allocated to each segment based on estimated use of corporate resources). A reconciliation of total segment assets to total assets presented in the accompanying consolidated balance sheets is as follows: As at As at September 30, 2019 December 31, 2018 $ $ Conventional Tanker Segment 2,059,873 2,069,854 Ship-to-Ship Transfer Segment 33,560 36,315 Cash and cash equivalents 76,705 54,917 Consolidated total assets 2,170,138 2,161,086

Short-Term Debt Short-Term Debt

Short-Term Debt Short-Term Debt - USD ($) $ in Millions	1 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2019	Nov. 30, 2018	Sep. 30, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Short-term debt, Maximum borrowing limit		$ 40
Short-term Debt [Line Items]
Line of Credit Facility, Increase (Decrease), Net	$ 55
Short-term Debt [Member]
Short-term Debt [Line Items]
Debt Instrument, Term			6 months
Short-term Debt [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate, Effective Percentage			5.50%	0.00%
Debt instrument, interest rate, stated percentage			3.50%
Short-term Debt, Maximum Amount Outstanding During Period			$ 50	$ 0
Minimum [Member]
Short-term Debt [Line Items]
Capital			$ 20

Short-Term Debt Short-term De_2

Short-Term Debt Short-term Debt (Notes)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Short-term Debt [Text Block]	Short-Term Debt In November 2018, Teekay Tankers Chartering Pte. Ltd. (or TTCL ) a wholly-owned subsidiary of the Company and a manager of the Company's RSAs entered into a working capital loan facility agreement (or the Working Capital Loan ), which initially provided available aggregate borrowings of up to $40.0 million for TTCL, and which was subsequently increased to $55.0 million , effective June 2019. Proceeds of the Working Capital Loan are used to provide working capital in relation to certain vessels trading in the RSAs and to fund pooling operations. The Working Capital Loan had an initial maturity date in August 2019, but is continually extended for further periods of six months thereafter until the lender gives notice in writing that no further extensions shall occur. Interest payments are based on LIBOR plus a margin of 3.5% . The Working Capital Loan is collateralized by the assets of TTCL. The Working Capital Loan requires the Company to maintain its paid-in capital contribution to the RSAs and the retained distributions of the RSA participants in an amount equal to the greater of (a) an amount equal to the minimum average capital contributed by the RSA participants per vessel in respect of the RSA (including cash, bunkers or other working capital contributions and amounts accrued to the RSA participants but unpaid) and (b) $20.0 million . As at September 30, 2019 , $50.0 million ( December 31, 2018 - nil ) was owing under this facility, and the effective interest rate on the facility was 5.5% ( December 31, 2018 - nil ). As of the date these consolidated financial statements were issued, the Company was in compliance with all covenants in respect of this facility.

Investments in and Advances to

Investments in and Advances to Equity Accounted Joint Venture	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Investments in and Advances to Equity Accounted Investments	Investment in and Advances to Equity-Accounted Joint Venture As at September 30, 2019 As at December 31, 2018 $ $ High-Q Joint Venture 26,418 25,766 The Company has a joint venture arrangement with Wah Kwong Maritime Transport Holdings Limited (or Wah Kwong ), whereby the Company has a 50% economic interest in the High-Q joint venture, which is jointly controlled by the Company and Wah Kwong. The High-Q joint venture owns one 2013-built Very Large Crude Carrier (or VLCC ), which traded on a fixed time charter-out contract that expired in May 2018. Under the fixed contract, the vessel earned a daily rate and an additional amount if the daily rate of sub-charters exceeded a certain threshold. The VLCC completed its dry dock in July 2018 and subsequently began trading on spot voyage charters in a pooling arrangement managed by a third party. As at September 30, 2019 , the High-Q joint venture had a loan of $33.5 million ( December 31, 2018 – $37.5 million ) outstanding with a financial institution. The loan is secured by a first-priority mortgage on the VLCC owned by the High-Q joint venture and 50% of the outstanding loan balance is guaranteed by the Company.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt As at As at September 30, 2019 December 31, 2018 $ $ Revolving Credit Facilities due through 2022 363,930 417,997 Term Loans due through 2021 248,947 323,995 Total principal 612,877 741,992 Less: unamortized discount and debt issuance costs (3,917 ) (6,586 ) Total debt 608,960 735,406 Less: current portion (101,295 ) (106,236 ) Non-current portion of long-term debt 507,665 629,170 As at September 30, 2019 , the Company had two revolving credit facilities (or the Revolvers ), which, as at such date, provided for aggregate borrowings of up to $382.3 million , of which $18.4 million was undrawn ( December 31, 2018 - $429.8 million , of which $11.8 million was undrawn). Interest payments are based on LIBOR plus margins. As at September 30, 2019 , such margins ranged between 2.00% and 2.75% ( December 31, 2018 - 2.00% and 2.75% ). The total amount available under the Revolvers will decrease by $3.0 million (remainder of 2019 ), $12.1 million ( 2020 ), $304.8 million ( 2021 ) and $62.4 million ( 2022 ). As at September 30, 2019 , the Company also had three term loans outstanding, which totaled $249.0 million ( December 31, 2018 - $324.0 million ). Interest payments on the term loans are based on a combination of a fixed rate of 5.4% ( December 31, 2018 - 5.4% ) and variable rates based on LIBOR plus margins. As at September 30, 2019 , the margins ranged from 0.3% to 2.0% ( December 31, 2018 - 0.3% to 2.0% ). The term loan repayments are made in quarterly or semi-annual payments. Two of the term loans also have a balloon or bullet repayment due at maturity in 2021. The Revolvers and term loans are further described below. In May 2019, the Company completed a $63.7 million sale-leaseback financing transaction related to two of the Company's vessels (note 8). The Company used the proceeds from the sale-leaseback transaction to prepay a portion of the Company's 2017 Revolver (as defined below). I n November 2018, the Company completed an $84.7 million sale-leaseback financing transaction relating to four of the Company's vessels (note 8 ). The Company used the proceeds from the sale-leaseback transaction to refinance one of the Company's corporate revolving credit facilities that matured in November 2018 and to prepay a portion of the Company's 2017 Revolver. In September 2018, the Company completed a $156.6 million sale-leaseback financing transaction relating to six of the Company's vessels (note 8 ). The Company used the proceeds from the sale-leaseback transaction to prepay a portion of the Company's 2017 Revolver. In December 2017, the Company entered into a $270.0 million long-term debt facility (or the 2017 Revolver ), which is scheduled to mature in December 2022 and which had an outstanding balance of $71.2 million as at September 30, 2019 ( December 31, 2018 - $125.3 million ). The 2017 Revolver is collateralized by five of the Company's vessels, together with other related security. The total net book value of the five vessels as at September 30, 2019 was $140.0 million ( December 31, 2018 - $192.6 million ). The 2017 Revolver requires that the Company maintain a minimum hull coverage ratio o f 125% of the total outstanding drawn balance for the facility period. Such requirement is assessed on a semi-annual basis with reference to vessel valuations compiled by two or more agreed upon third parties. Should the ratio drop below the required amount, the lender may request that the Company either prepay a portion of the loan in the amount of the shortfall or provide additional collateral in the amount of the shortfall, at the Company's option. As of September 30, 2019 , the hull coverage ratio was 243% ( December 31, 2018 - 163% ). The vessel values used in this ratio are appraised values provided by third parties where available or prepared by the Company based on second-hand sale and purchase market data. A decline in the tanker market could negatively affect the ratio. In addition, the Company is required to maintain minimum liquidity (cash, cash equivalents and undrawn committed revolving credit lines with at least six months to matu rity) of $35.0 million and at least 5% of the Company's total consolidated debt. In January 2016, the Company entered into a $894.4 million long-term debt facility (or the 2016 Debt Facility ), consisting of both a term loan of $98.5 million and a revolving credit component of $292.7 million , which are scheduled to mature in December 2020 and January 2021, respectively, and which had a total outstanding balance of $391.2 million as at September 30, 2019 ( December 31, 2018 - $450.3 million ). The 2016 Debt Facility is collateralized by 29 of the Company’s vessels, together with other related security. The total net book value of the 29 vessels as at September 30, 2019 was $930.9 million ( December 31, 2018 - $972.5 million ). The 2016 Debt Facility also requires that the Company maintain a minimum hull coverage ratio of 125% of the total outstanding drawn balance for the facility period. Such requirement is assessed on a semi-annual basis with reference to vessel valuations compiled by two or more agreed upon third parties. Should the ratio drop below the required amount, the lender may request that the Company either prepay a portion of the loan in the amount of the shortfall or provide additional collateral in the amount of the shortfall, at the Company’s option. As at September 30, 2019 , the hull coverage ratio was 192% ( December 31, 2018 - 137% ). The vessel values used in this ratio are appraised values provided by third parties where available or prepared by the Company based on second-hand sale and purchase market data. A decline in the tanker market could negatively affect the ratio. In addition, the Company is required to maintain minimum liquidity (cash, cash equivalents and undrawn committed revolving credit lines with at least six months to maturity) of $35.0 million and at least 5.0% of the Company’s total consolidated debt. The Company’s remaining two term loans, with a total outstanding balance of $150.4 million as at September 30, 2019 ( December 31, 2018 - $166.4 million ), which are scheduled to mature between October 2020 and August 2021, are guaranteed by Teekay Corporation (or Teekay ) and are collateralized by six of the Company’s vessels, together with other related security. One of the term loans contains covenants that require Teekay to maintain the greater of (a) free cash (cash and cash equivalents) and undrawn committed revolving credit lines with at least six months to maturity of at least $50.0 million and (b) an aggregate of free cash and undrawn committed revolving credit lines with at least six months to maturity of at least 5.0% of Teekay’s total consolidated debt (excluding the debt of Teekay LNG Partners L.P., (or TGP ) and its subsidiaries and the Company and its subsidiaries that are non-recourse to Teekay). The other term loan requires Teekay and the Company collectively to maintain the greater of (a) free cash (cash and cash equivalents) of at least $100.0 million and (b) an aggregate of free cash and undrawn committed revolving credit lines with at least six months to maturity of at least 7.5% of Teekay's total consolidated debt (excluding the debt of TGP and its subsidiaries). As of the date these consolidated financial statements were issued, the Company was in compliance with all covenants in respect of the Revolvers and term loans. Teekay has also advised the Company that Teekay is in compliance with all covenants relating to the revolving credit facilities and term loans to which the Company is a party. The weighted-average interest rate on the Company’s long-term debt as at September 30, 2019 was 4.2% ( December 31, 2018 - 4.6% ). This rate does not reflect the effect of the Company’s interest rate swap agreements (note 9 ). The aggregate annual long-term principal repayments required to be made by the Company under the Revolvers and term loans subsequent to September 30, 2019 are $25.4 million (remainder of 2019 ), $101.8 million ( 2020 ), $426.6 million ( 2021 ) and $59.1 million ( 2022 ).

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Lessee, Operating Leases [Text Block]	Operating Leases The Company charters-in vessels from other vessel owners on time-charter contracts, whereby the vessel owner provides use and technical operation of the vessel for the Company. A time charter-in contract is typically for a fixed period of time, although in certain cases, the Company may have the option to extend the charter. The Company typically pays the owner a daily hire rate that is fixed over the duration of the charter. The Company is generally not required to pay the daily hire rate during periods the vessel is not able to operate. The Company has determined that all of its time charter-in contracts contain both a lease component (lease of the vessel) and a non-lease component (technical operation of the vessel). The Company has allocated the contract consideration between the lease component and non-lease component on a relative standalone selling price basis. The standalone selling price of the non-lease component has been determined using a cost-plus approach, whereby the Company estimates the cost to technically operate the vessel using cost benchmarking studies prepared by a third party, when available, or internal estimates when not available, plus a profit margin. The standalone selling price of the lease component has been determined using an adjusted market approach, whereby the Company calculates a rate excluding the operating component based on a market time-charter rate information from published broker estimates, when available, or internal estimates when not available. Given that there are no observable standalone selling prices for either of these two components, judgment is required in determining the standalone selling price of each component. The discount rate of the lease is determined using the Company’s incremental borrowing rate, which is based on the fixed interest rate the Company could obtain when entering into a secured loan facility of similar terms. With respect to time charter-in contracts with an original term of more than one year, for the three and nine months ended September 30, 2019 , the Company incurred $6.4 million and $17.4 million of time-charter hire expense related to four time charter-in contracts, of which $3.6 million and $9.7 million were allocable to the lease component and $2.8 million and $7.7 million were allocable to the non-lease component. The $3.6 million and $9.7 million allocable to the lease component approximate the cash paid for the amounts included in lease liabilities and reflected as a reduction in operating cash flows for the three and nine months ended September 30, 2019 . Three of these time charter-in contracts include an option to extend the charter for an additional one -year term. Since it is not reasonably certain that the Company will exercise the options, the lease components of the options are not recognized as part of the right-of-use assets and lease liabilities. As at September 30, 2019 , the weighted-average remaining lease term and weighted-average discount rate for these time charter-in contracts were 1.5 years and 5.58% , respectively. The Company has elected to recognize the lease payments of short-term leases in the statement of loss on a straight-line basis over the lease term and variable lease payments in the period in which the obligation for those payments is incurred, which is consistent with the recognition of payment for the non-lease component. Short-term leases are leases with an original term of one year or less, excluding those leases with an option to extend the lease for greater than one year or an option to purchase the underlying asset that the lessee is deemed reasonably certain to exercise. For the three and nine months ended September 30, 2019 , the Company incurred $4.2 million and $13.4 million of time-charter hire expense related to time charter-in contracts classified as short-term leases, respectively. During the nine months ended September 30, 2019 , the Company chartered in two LR2 vessels and one Aframax vessel for periods of 24 months, which resulted in the Company recognizing right-of-use assets of $14.6 million and $7.8 million on the lease commencement dates for the LR2 vessels and Aframax vessel, respectively. A maturity analysis of the Company’s operating lease liabilities from time charter-in contracts (excluding short-term leases) as at September 30, 2019 is as follows: Lease Commitment Non-Lease Commitment Total Commitment $ $ $ As at September 30, 2019 Payments: October to December 2019 4,352 3,445 7,797 2020 16,956 13,406 30,362 2021 3,315 2,585 5,900 Total payments 24,623 19,436 44,059 Less: imputed interest (1,028 ) Carrying value of operating lease liabilities 23,595 As at September 30, 2019 , minimum commitments to be incurred by the Company under short-term time charter-in contracts, were approximately $4.3 million (remainder of 2019 ) and $2.7 million ( 2020 ). As at December 31, 2018 , minimum commitments to be incurred by the Company relating to eight chartered-in vessels accounted for as operating leases, i ncluding three workboats for the Company's lightering support services, were approximately $36.9 million ( 2019 ), $23.5 million ( 2020 ) and $2.0 million ( 2021 ).
Obligations Related to Finance Leases [Table Text Block]	As at As at September 30, 2019 December 31, 2018 $ $ Total obligations related to finance leases 420,934 375,289 Less: current portion (24,875 ) (20,896 ) Long-term obligations related to finance leases 396,059 354,393
Leases	Obligations Related to Finance Leases As at As at September 30, 2019 December 31, 2018 $ $ Total obligations related to finance leases 420,934 375,289 Less: current portion (24,875 ) (20,896 ) Long-term obligations related to finance leases 396,059 354,393 In May 2019, the Company completed a $63.7 million sale-leaseback financing transaction with a financial institution relating to two of the Company's Suezmax tankers, Aspen Spirit and Cascade Spirit . In November 2018, the Company completed an $84.7 million sale-leaseback financing transaction with a financial institution relating to four of the Company's tankers, consisting of two Aframax tankers, one Suezmax tanker and one LR2 product tanker, the Explorer Spirit, Navigator Spirit, Pinnacle Spirit and Trysil Spirit . In September 2018, the Company completed a $156.6 million sale-leaseback financing transaction with a financial institution relating to six of the Company's Aframax tankers, the Blackcomb Spirit, Emerald Spirit, Garibaldi Spirit, Peak Spirit, Tarbet Spirit and Whistler Spirit . In July 2017, the Company also completed a $153.0 million sale-leaseback financing transaction with a financial institution relating to four of the Company's Suezmax tankers, the Athens Spirit , Beijing Spirit , Moscow Spirit and Sydney Spirit . Under these arrangements, the Company transferred the vessels to subsidiaries of the financial institutions (or collectively, the Lessors ) and leased the vessels back from the Lessors on bareboat charters ranging from 9 - to 12 -year terms. The Company is obligated to purchase six of the Aframax vessels and two of the Suezmax vessels upon maturity of their respective bareboat charters. The Company also has the option to purchase each of the 16 tankers at various times starting between July 2020 and November 2021 until the end of their respective lease terms. The Company consolidates 14 of the 16 Lessors for financial reporting purposes as VIEs. The Company understands that these vessels and lease operations are the only assets and operations of the Lessors. The Company operates the vessels during the lease terms, and as a result, is considered to be the Lessors' primary beneficiary. The liabilities of the 14 Lessors are loans and are non-recourse to the Company. The amounts funded to the 14 Lessors in order to purchase the vessels materially match the funding to be paid by the Company's subsidiaries under these lease-back transactions. As a result, the amounts due by the Company's subsidiaries to the 14 Lessors considered as VIEs have been included in obligations related to finance leases as representing the Lessors' loans. Subsequent to the adoption of ASU 2016-02 on January 1, 2019, sale and leaseback transactions where the lessee has a purchase obligation are treated as a failed sale. Consequently, the Company has not derecognized the Aspen Spirit and Cascade Spirit and continues to depreciate the assets as if it was the legal owner. Proceeds received from the sale are set up as an obligation related to finance lease and bareboat charter hire payments made by the Company to the Lessor are allocated between interest expense and principal repayments on the obligation related to finance lease. The bareboat charters related to these vessels require that the Company maintain a minimum liquidity (cash, cash equivalents and undrawn committed revolving credit lines with at least six months to maturity) of $35.0 million and at least 5.0% of the Company's consolidated debt and obligations related to finance leases (excluding applicable security deposits reflected in restricted cash - long-term on the Company's consolidated balance sheets). Four of the bareboat charters require the Company to maintain, for each vessel, a minimum hull coverage ratio of 90% of the total outstanding principal balance during the first three years of the lease period and 100% of the total outstanding principal balance thereafter. As at September 30, 2019 , this ratio was approximately 121% ( December 31, 2018 - 101% ). Six of the bareboat charters require the Company to maintain, for each vessel, a minimum hull coverage ratio of 75% of the total outstanding principal balance during the first year of the lease period, 78% for the second year, 80% for the following two years and 90% of the total outstanding principal balance thereafter. As at September 30, 2019 , this ratio was approximately 113% ( December 31, 2018 - 91% ). Four of the bareboat charters also require the Company to maintain, for each vessel, a minimum hull overage ratio of 100% of the total outstanding principal balance. As at September 30, 2019 , this ratio was approximately 153% ( December 31, 2018 - 122% ). The remaining two bareboat charters also require the Company to maintain, for each vessel, a minimum hull coverage ratio of 75% of the total outstanding principal balance during the first year of the lease period, 78% for the second year, 80% for the following two years and 90% of the total outstanding principal balance thereafter. As at September 30, 2019 , this ratio was approximately 108% ( December 31, 2018 - nil ). Such requirement is assessed annually with reference to vessel valuations compiled by one or more agreed upon third parties. As of the date these consolidated financial statements were issued, the Company was in compliance with all covenants in respect of its obligations related to finance leases. The weighted-average interest rate on the Company’s obligations related to finance leases as at September 30, 2019 was 7.7% ( December 31, 2018 - 7.5% ). As at September 30, 2019 and December 31, 2018 , the Company's total remaining commitments related to the financial liabilities of these Suezmax, Aframax and LR2 product tankers were approximately $615.9 million (December 31, 2018 - $557.1 million ) , including imputed interest of $195.0 million (December 31, 2018 - $181.8 million ), repayable from 2019 through 2030, as indicated below: Commitments Year September 30, 2019 December 31, 2018 Remainder of 2019 14,242 47,962 2020 56,364 47,373 2021 56,202 47,237 2022 56,193 47,230 2023 56,184 47,222 Thereafter 376,749 320,064

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Interest rate swap agreements The Company uses derivative instruments in accordance with its overall risk management policies. The Company enters into interest rate swap agreements which exchange a receipt of floating interest for a payment of fixed interest to reduce the Company’s exposure to interest rate variability on its outstanding floating-rate debt. The Company has not designated, for accounting purposes, its interest rate swaps as cash flow hedges of its U.S. Dollar LIBOR-denominated borrowings. As at September 30, 2019 , the Company was committed to the following interest rate swap agreements: Interest Rate Notional Amount Fair Value / Carrying Amount of Asset Fair Value /Carrying Amount of Liability Remaining Term Fixed Interest Rate Index $ $ $ (years) (%) (1) LIBOR-Based Debt: U.S. Dollar-denominated interest rate swaps (2) LIBOR 57,852 167 — 1.3 1.46 U.S. Dollar-denominated interest rate swaps LIBOR 150,000 383 49 1.3 1.55 U.S. Dollar-denominated interest rate swaps LIBOR 50,000 365 — 1.3 1.16 (1) Excludes the margin the Company pays on its variable-rate debt, which, as of September 30, 2019 , ranged from 0.30% to 3.50% . (2) Notional amount reduces quarterly. The Company is potentially exposed to credit loss in the event of non-performance by the counterparty to the interest rate swap agreements in the event that the fair value results in an asset being recorded. In order to minimize counterparty risk, the Company only enters into interest rate swap agreements with counterparties that are rated A– or better by Standard & Poor’s or A3 or better by Moody’s at the time transactions are entered into. Forward freight agreements The Company uses forward freight agreements (or FFAs ) in non-hedge-related transactions to increase or decrease its exposure to spot market rates, within defined limits. Net gains and losses from FFAs are recorded within realized and unrealized gain (loss) on derivative instruments in the Company's consolidated statements of loss. The following table presents the location and fair value amounts of derivative instruments, segregated by type of contract, on the Company’s consolidated balance sheets. Current portion of derivative assets Derivative assets Accounts receivable (Accrued liabilities) Current portion of derivative liabilities Derivative liabilities $ $ $ $ As at September 30, 2019 Interest rate swap agreements 833 82 365 — (49 ) Forward freight agreements 1,045 — — — — 1,878 82 365 — (49 ) As at December 31, 2018 Interest rate swap agreements 2,905 2,973 422 — — Forward freight agreements — — (3 ) (57 ) — 2,905 2,973 419 (57 ) — Realized and unrealized gains (losses) relating to the interest rate swaps and FFAs are recognized in earnings and reported in realized and unrealized gain (loss) on derivative instruments in the Company’s consolidated statements of loss as follows: Three Months Ended Three Months Ended September 30, 2019 September 30, 2018 Realized gains Unrealized (losses) gains Total Realized gains (losses) Unrealized gains (losses) Total $ $ $ $ $ $ Interest rate swap agreements 613 (541 ) 72 711 13 724 Forward freight agreements 435 946 1,381 (119 ) (9 ) (128 ) 1,048 405 1,453 592 4 596 Nine Months Ended Nine Months Ended September 30, 2019 September 30, 2018 Realized gains Unrealized (losses) gains Total Realized gains (losses) Unrealized gains Total $ $ $ $ $ $ Interest rate swap agreements 2,395 (5,010 ) (2,615 ) 1,575 3,262 4,837 Forward freight agreements 393 1,050 1,443 (137 ) 25 (112 ) 2,788 (3,960 ) (1,172 ) 1,438 3,287 4,725

Other Income

Other Income	9 Months Ended
	Sep. 30, 2019
Other Nonoperating Income [Abstract]
Components of Other Expense	Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 $ $ $ $ Foreign exchange gain 918 1,251 1,100 6,025 Other income 15 — 82 49 Total 933 1,251 1,182 6,074
Other Nonoperating Income and Expense [Text Block]	The components of other income are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 $ $ $ $ Foreign exchange gain 918 1,251 1,100 6,025 Other income 15 — 82 49 Total 933 1,251 1,182 6,074

Freight Tax and Other Tax Expen

Freight Tax and Other Tax Expense Freight Tax and Other Tax Expense (Notes)	9 Months Ended
	Sep. 30, 2019
Other Liabilities Disclosure [Abstract]
Other Liabilities Disclosure [Text Block]	The following table reflects changes in uncertain tax positions relating to freight tax liabilities, which are recorded in other long-term liabilities on the Company's consolidated balance sheets: Nine Months Ended September 30 2019 2018 Balance of unrecognized tax benefits as at January 1 32,059 26,054 Increases for positions related to the current year 2,067 2,099 Changes for positions taken in prior years 2,114 1,852 Decreases related to statute of limitations — (93 ) Balance of unrecognized tax benefits as at September 30 36,240 29,912 The Company does not presently anticipate its uncertain tax positions will significantly increase in the next 12 months; however, this is dependent on the jurisdictions of the trading activity of its vessels. The Company reviews its freight tax obligations on a regular basis and may update its assessment of its tax positions based on available information at that time. Such information may include legal advice as to applicability of freight taxes in relevant jurisdictions. Freight tax regulations are subject to change and interpretation; therefore, the amounts recorded by the Company may change accordingly.

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Financial Instruments	Financial Instruments a. Fair Value Measurements For a description of how the Company estimates fair value and for a description of the fair value hierarchy levels, see Item 18 - Financial Statements: Note 13 to the Company’s audited consolidated financial statements filed with its Annual Report on Form 20-F for the year ended December 31, 2018 . The following table includes the estimated fair value and carrying value of those assets and liabilities that are measured at fair value on a recurring basis, as well as the estimated fair value of the Company’s financial instruments that are not accounted for at the fair value on a recurring basis. September 30, 2019 December 31, 2018 Fair Value Hierarchy Level Carrying Amount Asset / (Liability) $ Fair Value Asset / (Liability) $ Carrying Amount Asset / (Liability) $ Fair Value Asset / (Liability) $ Recurring: Cash, cash equivalents and restricted cash Level 1 82,483 82,483 60,507 60,507 Derivative instruments (note 9) Interest rate swap agreements (1) Level 2 866 866 5,878 5,878 Forward freight agreements (1) Level 2 1,045 1,045 (57 ) (57 ) Other: Short-term debt (note 7) Level 2 (50,000 ) (50,000 ) — — Advances to equity-accounted for joint venture (2) 9,930 (2) 9,930 (2) Long-term debt, including current portion (note 6) Level 2 (608,960 ) (604,434 ) (735,406 ) (723,031 ) Obligations related to finance leases, including current portion (note 8) Level 2 (420,934 ) (451,145 ) (375,289 ) (377,652 ) (1) The fair value of the Company’s interest rate swap agreements and FFAs at September 30, 2019 and December 31, 2018 excludes accrued interest income and expenses which are recorded in accounts receivables and accrued liabilities, respectively, on the unaudited consolidated balance sheets. (2) The advances to its equity-accounted joint venture, together with the Company’s investment in the equity-accounted joint venture, form the net aggregate carrying value of the Company’s interests in the equity-accounted joint venture in these consolidated financial statements. The fair values of the individual components of such aggregate interests as at September 30, 2019 and December 31, 2018 were not determinable. b. Financing Receivables The following table contains a summary of the Company’s financing receivables by type and the method by which the Company monitors the credit quality of its financing receivables on a quarterly basis. September 30, 2019 December 31, 2018 Class of Financing Receivable Credit Quality Indicator Grade $ $ Advances to equity-accounted joint venture Other internal metrics Performing 9,930 9,930 Total 9,930 9,930

Capital Stock and Stock-Based C

Capital Stock and Stock-Based Compensation	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Capital Stock and Stock-Based Compensation	Capital Stock and Equity-Based Compensation The authorized capital stock of the Company at September 30, 2019 was 100,000,000 shares of preferred stock ( December 31, 2018 - 100,000,000 ), with a par value of $0.01 per share, 485,000,000 shares of Class A common stock ( December 31, 2018 - 485,000,000 ), with a par value of $0.01 per share, and 100,000,000 shares of Class B common stock ( December 31, 2018 - 100,000,000 ), with a par value of $0.01 per share. A share of Class A common stock entitles the holder to one vote per share while a share of Class B common stock entitles the holder to five votes per share, subject to a 49% aggregate Class B common stock voting power maximum. As of September 30, 2019 , the Company had 232.0 million shares of Class A common stock ( December 31, 2018 – 231.6 million ), 37.0 million shares of Class B common stock ( December 31, 2018 – 37.0 million ) and no shares of preferred stock ( December 31, 2018 – nil ) issued and outstanding. During March 2019, the Company granted, under the Teekay Tankers Ltd. 2007 Long-Term Incentive Plan, a total of 159,375 shares of Class A common stock with an aggregate value of $0.2 million and 0.5 million stock options with an exercise price of $1.00 per share to the Company’s non-management directors as part of their annual compensation for 2018 . During March 2018, 0.5 million stock options with an exercise price of $1.22 per share were granted to non-management directors of the Company. These stock options have a ten -year term and vest immediately. For the nine months ended September 30, 2019 and 2018, the compensation relating to the granting of such stock and stock options has been included in general and administrative expenses in the amount of $0.3 million and $0.4 million , respectively. The Company also grants stock options and restricted stock units as incentive-based compensation under the Teekay Tankers Ltd. 2007 Long-Term Incentive Plan to the officers of the Company and certain employees of Teekay subsidiaries that provide services to the Company. The Company measures the cost of such awards using the grant date fair value of the award and recognizes that cost, net of estimated forfeitures, over the requisite service period. The requisite service period consists of the period from the grant date of the award to the earlier of the date of vesting or the date the recipient becomes eligible for retirement. For stock-based compensation awards subject to graded vesting, the Company calculates the value for the award as if it was one single award with one expected life and amortizes the calculated expense for the entire award on a straight-line basis over the requisite service period. The compensation cost of the Company's stock-based compensation awards is reflected in general and administrative expenses in the Company’s consolidated statements of loss. During March 2019, the Company granted 1.4 million ( 2018 - 0.7 million ) stock options with an exercise price of $1.00 ( 2018 - $1.22 ) per share to the officers of the Company and certain employees of Teekay subsidiaries that provide services to the Company. Each stock option has a ten -year term and vests equally over three years from the grant date. The weighted-average fair value of the stock options granted in 2019 to non-management directors, officers and certain employees of Teekay subsidiaries that provide services to the Company was $0.35 ( 2018 - $0.35 ) per option, estimated on the grant date using the Black-Scholes option pricing model. The following assumptions were used in computing the fair value of the stock options granted: expected volatility of 48.7% ( 2018 - 48.7% ); expected life of five years ( 2018 - five years); dividend yield of 3.0% ( 2018 - 5.5% ); and risk-free interest rate of 2.4% ( 2018 - 2.6% ). The expected life of the stock options granted was estimated using the historical exercise behavior of employees of Teekay that receive stock options from Teekay. The expected volatility was based on historical volatility of the Company's share price as calculated using historical data during the five years prior to the grant date. During March 2019, the Company also granted 0.6 million ( 2018 - 0.8 million ) restricted stock units to the officers of the Company and certain employees of Teekay subsidiaries that provide services to the Company with an aggregate fair value of $0.6 million ( 2018 - $0.9 million ). Each restricted stock unit is equal to one share of the Company’s common stock plus reinvested distributions from the grant date to the vesting date. The restricted stock units vest equally over three years from the grant date. Any portion of a restricted stock unit award that is not vested on the date of the recipient’s termination of service is cancelled, unless the recipient's termination arises as a result of the recipient’s retirement and, in this case, the restricted stock unit award will continue to vest in accordance with the vesting schedule. Upon vesting, the value of the restricted stock unit awards, net of withholding taxes, is paid to each recipient in the form of common stock. During the three and nine months ended September 30, 2019 and 2018 , the Company recorded $0.2 million and $0.9 million ( 2018 - $0.2 million and $0.8 million ), respectively, of expenses related to the restricted stock units and stock options. During the nine months ended September 30, 2019 , a total of 0.4 million restricted stock units ( 2018 - 0.3 million ) with a market value of $0.5 million ( 2018 - $0.3 million ) vested and were paid to the grantees by issuing 0.3 million shares ( 2018 - 0.2 million shares) of Class A common stock, net of withholding taxes.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Management Fee - Related and Other a. The Company's operations are conducted in part by its subsidiaries, which receive services from Teekay's wholly-owned subsidiary, Teekay Shipping Ltd. (or the Manager, as successor by merger to Teekay Tankers Management Services Ltd.) and its affiliates. The Manager provides various services under a long-term management agreement (the Management Agreement ). Commencing October 1, 2018, the Company elected to receive commercial and technical management services for its owned and leased vessels (other than certain former Teekay Investment Ltd. (or TIL ) vessels, which are managed by a third party) from its wholly-owned subsidiaries and no longer contracts these services from the Manager. Prior to this date, the Manager provided these services to the Company, which it did by subcontracting such services from the Company's subsidiary, Teekay Tanker Operations Ltd. (or TTOL ) and its affiliates. Certain of the Company’s vessels participate in RSAs that are managed by the Company's subsidiaries, TTOL or Teekay Tankers Chartering Pte Ltd. b. Amounts received and (paid by) the Company for related party transactions for the periods indicated were as follows: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 $ $ $ $ Vessel operating expenses - technical management fee (i) — (2,800 ) — (8,900 ) Strategic and administrative service fees (ii) (7,437 ) (7,875 ) (23,179 ) (25,204 ) Secondment fees (iii) (21 ) (189 ) (120 ) (548 ) LNG service revenues (iv) (150 ) 72 1,979 344 Technical management fee revenue (v) 169 3,490 596 9,819 Service revenues (vi) 100 343 317 758 (i) The cost of ship management services provided by the Manager has been presented as vessel operating expenses on the Company's consolidated statements of loss. There were no technical management fees paid to a related party for the three and nine months ended September 30, 2019 as the Company elected to receive technical management services for its owned and leased vessels (other than certain former TIL vessels, which are managed by a third party) from its wholly-owned subsidiaries and no longer contracts these services from the Manager. (ii) The Manager’s strategic and administrative service fees have been presented in general and administrative expenses, except for fees related to technical management services, which have been presented in vessel operating expenses on the Company’s consolidated statements of loss. The Company’s executive officers are employees of Teekay or subsidiaries thereof, and their compensation (other than any awards under the Company’s long-term incentive plan described in note 13) is set and paid by Teekay or such other subsidiaries. The Company reimburses Teekay for time spent by its executive officers on the Company’s management matters through the strategic portion of the management fee. (iii) The Company pays secondment fees for services provided by some employees of Teekay. Secondment fees have been presented in general and administrative expenses, except for fees related to technical management services, which have been presented in vessel operating expenses on the Company's consolidated statements of loss. (iv) In November 2016, the Company's ship-to-ship transfer business signed an operational and maintenance subcontract with Teekay LNG Bahrain Operations L.L.C., an entity wholly-owned by TGP, for the Bahrain LNG Import Terminal. The terminal is owned by Bahrain LNG W.I.L., a joint venture for which Teekay LNG Operating L.L.C., an entity wholly-owned by TGP, has a 30% interest. The sub-contract ended in April 2019. (v) The Company receives reimbursements from Teekay, which subcontracts technical management services from the Manager. These reimbursements have been presented in general and administrative expenses on the Company's consolidated statements of loss. (vi) The Company recorded revenue relating to TTOL's administration of certain RSAs and provision of certain commercial services to participants in the arrangements. c. The Manager and other subsidiaries of Teekay collect revenues and remit payments for expenses incurred by the Company’s vessels. Such amounts, which are presented on the Company’s consolidated balance sheets in "due from affiliates" or "due to affiliates," as applicable, are without interest or stated terms of repayment. In addition, $7.8 million and $7.6 million were payable as crewing and manning costs as at September 30, 2019 and December 31, 2018 , respectively, and such amounts are included in accrued liabilities in the consolidated balance sheets. These crewing and manning costs will be payable as reimbursement to the Manager once they are paid by the Manager to the vessels' crew. The amounts owing from certain RSAs, which are winding up, are reflected in the consolidated balance sheets as pool receivables from affiliates, and these amounts are without interest and are repayable upon the terms contained within the applicable RSA. In addition, the Company had advanced $ nil and $34.9 million as at September 30, 2019 and December 31, 2018 , respectively, to certain RSAs for working capital purposes. These activities, which are reflected in the Company's consolidated balance sheets as due from affiliates, are without interest or stated terms of repayment. d. Pursuant to certain RSAs, TTOL provides certain commercial services to the RSA participants and administers the RSAs in exchange for a fee currently equal to 1.25% of the gross revenues attributable to each RSA participant’s vessels and a fixed amount per vessel per day which ranges from $275 to $350 . Voyage revenues and voyage expenses of the Company’s vessels operating in these RSAs are pooled with the voyage revenues and voyage expenses of other RSA participants. The resulting net pool revenues, calculated on a time-charter equivalent basis, are allocated to the RSA participants according to an agreed formula. The pool receivables from affiliates as at September 30, 2019 and December 31, 2018 were $0.6 million and $56.5 million , respectively. The decrease in the pool receivables from affiliates was due to the transition of vessels into the new RSA structure under a newly formed subsidiary of the Company, TTCL, during 2019. e. Pursuant to a service agreement with the Teekay Aframax RSA, from time to time, the Company may hire vessels to perform full service lightering services. During the three and nine months ended September 30, 2019 , the Company recognized $0.1 million and $7.5 million ( September 30, 2018 - $3.3 million and $19.1 million ), respectively, related to vessels that were chartered-in from the RSA to assist with full service lightering operations. These amounts have been presented in voyage expenses on the Company's consolidated statements of loss.

Sales of Vessels

Sales of Vessels - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Sale of Vessel [Text Block]	Sale of Vessel The Company's consolidated statements of loss for the nine months ended September 30, 2018 include a net gain on sale of vessel of $0.2 million relating to one lightering support vessel, which was sold and delivered to its buyer in the second quarter of 2018.
Sales of Vessels	$ 0	$ 589

Loss Per Share

Loss Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Loss Per Share	15. Loss Per Share The net loss available for common shareholders and loss per common share are presented in the table below: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 $ $ $ $ Net loss (19,850 ) (17,484 ) (21,710 ) (64,050 ) Weighted average number of common shares - basic 268,990,399 268,558,556 268,887,485 268,470,804 Dilutive effect of stock-based awards — — — — Weighted average number of common shares - diluted 268,990,399 268,558,556 268,887,485 268,470,804 Loss per common share: – Basic (0.07 ) (0.07 ) (0.08 ) (0.24 ) – Diluted (0.07 ) (0.07 ) (0.08 ) (0.24 ) Stock-based awards that have an anti-dilutive effect on the calculation of diluted earnings per common share are excluded from this calculation. In the periods where a loss attributable to shareholders has been incurred, all stock-based awards are anti-dilutive.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	9 Months Ended
	Sep. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow Information Total cash, cash equivalents and restricted cash is as follows: As at As at As at As at September 30, 2019 December 31, 2018 September 30, 2018 December 31, 2017 $ $ $ $ Cash and cash equivalents 76,705 54,917 54,361 71,439 Restricted cash – current 2,341 2,153 1,794 1,599 Restricted cash – long-term 3,437 3,437 2,672 2,672 82,483 60,507 58,827 75,710 The Company maintains restricted cash deposits relating to certain FFAs (note 9 ), LNG terminal management and leasing arrangements (note 8 ). Non-cash items related to operating lease right-of-use assets and operating lease liabilities are as follows: For the nine months ended September 30, 2019 September 30, 2018 $ $ Leased assets obtained in exchange for new operating lease liabilities 22,432 —

Subsequent Events (Notes)

Subsequent Events (Notes)	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events [Text Block]	20. Subsequent Events a. In November 2019, the Board of Directors determined to effect a one -for- eight reverse stock split of the Company's Class A common shares, par value $0.01 per share, and Class B common shares, par value $0.01 per share, which will be approved by its controlling shareholder, Teekay Corporation. The reverse stock split is expected to take effect, and the Company's Class A common shares are expected to begin trading on a split-adjusted basis on the New York Stock Exchange ( NYSE ), as of the opening of trading on November 25, 2019. When the reverse stock split becomes effective, every eight of the Company's issued and outstanding common shares will be combined into one issued common share, without any change to the par value per share. This will reduce the number of issued and outstanding Class A and B common shares from approximately 232.0 million and 37.0 million to approximately 29.0 million and 4.6 million , respectively. These consolidated financial statements have not been retrospectively adjusted to reflect the expected changes in the number of issued and outstanding common shares from this reverse stock split.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Accounting	The unaudited interim consolidated financial statements (or consolidated financial statements ) have been prepared in accordance with United States generally accepted accounting principles (or GAAP ). These consolidated financial statements include the accounts of Teekay Tankers Ltd., its wholly-owned subsidiaries, equity-accounted joint venture and any variable interest entities (or VIEs ) of which it is the primary beneficiary (collectively, the Company ). The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Certain information and footnote disclosures required by GAAP for complete annual financial statements have been omitted and, therefore, these consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2018 , filed on Form 20-F with the U.S. Securities and Exchange Commission (or the SEC ) on April 10, 2019. In the opinion of management, these consolidated financial statements reflect all adjustments, consisting solely of a normal recurring nature, necessary to present fairly, in all material respects, the Company’s consolidated financial position, results of operations, and cash flows for the interim periods presented. The results of operations for the interim periods presented are not necessarily indicative of those for a full fiscal year. Intercompany balances and transactions have been eliminated upon consolidation. Effective March 31, 2019 , the Company separately presents bunker and lube oil inventory on the Company’s consolidated balance sheet. Such amounts were previously classified as prepaid expenses. Bunker and lube oil inventory increased significantly as of the first quarter of 2019, as a result of changes to the Company’s revenue sharing arrangements (or RSAs ) whereby the Company now directly procures and has legal title to the bunker fuel for the vessels in the RSAs, with such assets being used as collateral for the new working capital loan arrangement entered into by the Company. Bunker and lube oil inventory is stated at cost, which is determined on a first-in, first-out basis. Comparative figures have been reclassified to conform to the presentation adopted in the current period.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table contains a breakdown of the Company's revenue by contract type for the three and nine months ended September 30, 2019 and September 30, 2018 . All revenue is part of the Company's conventional tanker segment , except for revenue for ship-to-ship support services and LNG terminal management, consultancy, procurement and other related services, which are part of the Company's ship-to-ship transfer segment. The Company’s lease income consists of the revenue from its voyage charters and time-charters. Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 $ $ $ $ Voyage charter revenues Suezmax 85,523 90,267 268,972 243,771 Aframax 51,075 29,210 164,381 76,952 LR2 23,989 16,712 84,001 40,312 Full service lightering 12,447 15,858 58,902 70,982 Total 173,034 152,047 576,256 432,017 Time-charter revenues Aframax — 7,784 1,837 31,608 Suezmax 1,909 2,909 4,938 13,063 LR2 — 1,633 — 7,149 Total 1,909 12,326 6,775 51,820 Other revenues Ship-to-ship support services 4,649 8,217 17,810 22,452 Commercial management 1,893 2,050 6,219 6,246 LNG terminal management, consultancy, procurement and other 819 1,275 10,022 3,504 Total 7,361 11,542 34,051 32,202 Total revenues 182,304 175,915 617,082 516,039

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Company's Revenue and Income from Operations by Segment	The following tables include results for the Company’s revenues and (loss) income from operations by segment for the three and nine months ended September 30, 2019 and September 30, 2018 . Three Months Ended September 30, 2019 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 176,836 8,685 (3,217 ) 182,304 Voyage expenses (90,943 ) — 3,217 (87,726 ) Vessel operating expenses (41,833 ) (6,706 ) — (48,539 ) Time-charter hire expenses (9,331 ) (1,306 ) — (10,637 ) Depreciation and amortization (30,634 ) (902 ) — (31,536 ) General and administrative expenses (3) (7,955 ) (784 ) — (8,739 ) Loss from operations (3,860 ) (1,013 ) — (4,873 ) Equity income 68 — — 68 Three Months Ended September 30, 2018 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 166,423 12,019 (2,527 ) 175,915 Voyage expenses (85,575 ) — 2,527 (83,048 ) Vessel operating expenses (43,432 ) (8,729 ) — (52,161 ) Time-charter hire expenses (2,935 ) (1,382 ) — (4,317 ) Depreciation and amortization (28,532 ) (1,063 ) — (29,595 ) General and administrative expenses (3) (7,985 ) (762 ) — (8,747 ) Restructuring charges — (213 ) — (213 ) Loss from operations (2,036 ) (130 ) — (2,166 ) Equity loss (359 ) — — (359 ) Nine Months Ended September 30, 2019 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 589,250 36,421 (8,589 ) 617,082 Voyage expenses (286,322 ) — 8,589 (277,733 ) Vessel operating expenses (129,555 ) (27,171 ) — (156,726 ) Time-charter hire expenses (26,497 ) (4,380 ) — (30,877 ) Depreciation and amortization (89,422 ) (2,637 ) — (92,059 ) General and administrative expenses (3) (25,030 ) (2,382 ) — (27,412 ) Income (loss) from operations 32,424 (149 ) — 32,275 Equity income 652 — — 652 Nine Months Ended September 30, 2018 Conventional Tanker Segment Ship-to-Ship Transfer Segment Inter-segment Adjustment (1) Total $ $ $ $ Revenues (2) 490,083 35,061 (9,105 ) 516,039 Voyage expenses (259,079 ) — 9,105 (249,974 ) Vessel operating expenses (131,886 ) (25,922 ) — (157,808 ) Time-charter hire expenses (10,326 ) (4,371 ) — (14,697 ) Depreciation and amortization (85,171 ) (3,427 ) — (88,598 ) General and administrative expenses (3) (25,385 ) (2,554 ) — (27,939 ) Gain on sale of vessel — 170 — 170 Restructuring charges (152 ) (1,043 ) — (1,195 ) Loss from operations (21,916 ) (2,086 ) — (24,002 ) Equity income 265 — — 265 (1) The ship-to-ship transfer segment provides lightering support services to the conventional tanker segment for full service lightering operations and the pricing for such services was based on actual costs incurred. (2) Revenues, net of the inter-segment adjustment, earned from the ship-to-ship transfer segment are reflected in Other Revenues in the Company's consolidated statements of loss. (3) Includes direct general and administrative expenses and indirect general and administrative expenses (allocated to each segment based on estimated use of corporate resources).
Reconciliation of Total Segment Assets to Total Assets Presented in Consolidated Balance Sheets	A reconciliation of total segment assets to total assets presented in the accompanying consolidated balance sheets is as follows: As at As at September 30, 2019 December 31, 2018 $ $ Conventional Tanker Segment 2,059,873 2,069,854 Ship-to-Ship Transfer Segment 33,560 36,315 Cash and cash equivalents 76,705 54,917 Consolidated total assets 2,170,138 2,161,086

Investments in and Advances t_2

Investments in and Advances to Equity Accounted Joint Venture (Tables)	9 Months Ended
	Sep. 30, 2019
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Investments in and Advances to Equity Accounted Investments	As at September 30, 2019 As at December 31, 2018 $ $ High-Q Joint Venture 26,418 25,766

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Summary of Long-Term Debt	As at As at September 30, 2019 December 31, 2018 $ $ Revolving Credit Facilities due through 2022 363,930 417,997 Term Loans due through 2021 248,947 323,995 Total principal 612,877 741,992 Less: unamortized discount and debt issuance costs (3,917 ) (6,586 ) Total debt 608,960 735,406 Less: current portion (101,295 ) (106,236 ) Non-current portion of long-term debt 507,665 629,170

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Schedule of Future Minimum Lease Payments for Finance Leases [Table Text Block]	Commitments Year September 30, 2019 December 31, 2018 Remainder of 2019 14,242 47,962 2020 56,364 47,373 2021 56,202 47,237 2022 56,193 47,230 2023 56,184 47,222 Thereafter 376,749 320,064
Lessee, Operating Lease, Disclosure [Table Text Block]	Lease Commitment Non-Lease Commitment Total Commitment $ $ $ As at September 30, 2019 Payments: October to December 2019 4,352 3,445 7,797 2020 16,956 13,406 30,362 2021 3,315 2,585 5,900 Total payments 24,623 19,436 44,059 Less: imputed interest (1,028 ) Carrying value of operating lease liabilities 23,595 As at September 30, 2019 , minimum commitments to be incurred by the Company under short-term time charter-in contracts, were approximately $4.3 million (remainder of 2019 ) and $2.7 million ( 2020 ). As at December 31, 2018 , minimum commitments to be incurred by the Company relating to eight chartered-in vessels accounted for as operating leases, i ncluding three workboats for the Company's lightering support services, were approximately $36.9 million ( 2019 ), $23.5 million ( 2020 ) and $2.0 million ( 2021 ).
Obligations Related to Finance Leases [Table Text Block]	As at As at September 30, 2019 December 31, 2018 $ $ Total obligations related to finance leases 420,934 375,289 Less: current portion (24,875 ) (20,896 ) Long-term obligations related to finance leases 396,059 354,393

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Interest Rate Swap Positions	As at September 30, 2019 , the Company was committed to the following interest rate swap agreements: Interest Rate Notional Amount Fair Value / Carrying Amount of Asset Fair Value /Carrying Amount of Liability Remaining Term Fixed Interest Rate Index $ $ $ (years) (%) (1) LIBOR-Based Debt: U.S. Dollar-denominated interest rate swaps (2) LIBOR 57,852 167 — 1.3 1.46 U.S. Dollar-denominated interest rate swaps LIBOR 150,000 383 49 1.3 1.55 U.S. Dollar-denominated interest rate swaps LIBOR 50,000 365 — 1.3 1.16 (1) Excludes the margin the Company pays on its variable-rate debt, which, as of September 30, 2019 , ranged from 0.30% to 3.50% . (2) Notional amount reduces quarterly.
Schedule of Derivative Instruments	The following table presents the location and fair value amounts of derivative instruments, segregated by type of contract, on the Company’s consolidated balance sheets. Current portion of derivative assets Derivative assets Accounts receivable (Accrued liabilities) Current portion of derivative liabilities Derivative liabilities $ $ $ $ As at September 30, 2019 Interest rate swap agreements 833 82 365 — (49 ) Forward freight agreements 1,045 — — — — 1,878 82 365 — (49 ) As at December 31, 2018 Interest rate swap agreements 2,905 2,973 422 — — Forward freight agreements — — (3 ) (57 ) — 2,905 2,973 419 (57 ) —
Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location	Realized and unrealized gains (losses) relating to the interest rate swaps and FFAs are recognized in earnings and reported in realized and unrealized gain (loss) on derivative instruments in the Company’s consolidated statements of loss as follows: Three Months Ended Three Months Ended September 30, 2019 September 30, 2018 Realized gains Unrealized (losses) gains Total Realized gains (losses) Unrealized gains (losses) Total $ $ $ $ $ $ Interest rate swap agreements 613 (541 ) 72 711 13 724 Forward freight agreements 435 946 1,381 (119 ) (9 ) (128 ) 1,048 405 1,453 592 4 596 Nine Months Ended Nine Months Ended September 30, 2019 September 30, 2018 Realized gains Unrealized (losses) gains Total Realized gains (losses) Unrealized gains Total $ $ $ $ $ $ Interest rate swap agreements 2,395 (5,010 ) (2,615 ) 1,575 3,262 4,837 Forward freight agreements 393 1,050 1,443 (137 ) 25 (112 ) 2,788 (3,960 ) (1,172 ) 1,438 3,287 4,725

Freight Tax and Other Tax Exp_2

Freight Tax and Other Tax Expense (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Other Liabilities [Table Text Block]	The following table reflects changes in uncertain tax positions relating to freight tax liabilities, which are recorded in other long-term liabilities on the Company's consolidated balance sheets: Nine Months Ended September 30 2019 2018 Balance of unrecognized tax benefits as at January 1 32,059 26,054 Increases for positions related to the current year 2,067 2,099 Changes for positions taken in prior years 2,114 1,852 Decreases related to statute of limitations — (93 ) Balance of unrecognized tax benefits as at September 30 36,240 29,912

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Fair Value and Carrying Value of Assets and Liabilities Measured on Recurring and Non-recurring Basis	The following table includes the estimated fair value and carrying value of those assets and liabilities that are measured at fair value on a recurring basis, as well as the estimated fair value of the Company’s financial instruments that are not accounted for at the fair value on a recurring basis. September 30, 2019 December 31, 2018 Fair Value Hierarchy Level Carrying Amount Asset / (Liability) $ Fair Value Asset / (Liability) $ Carrying Amount Asset / (Liability) $ Fair Value Asset / (Liability) $ Recurring: Cash, cash equivalents and restricted cash Level 1 82,483 82,483 60,507 60,507 Derivative instruments (note 9) Interest rate swap agreements (1) Level 2 866 866 5,878 5,878 Forward freight agreements (1) Level 2 1,045 1,045 (57 ) (57 ) Other: Short-term debt (note 7) Level 2 (50,000 ) (50,000 ) — — Advances to equity-accounted for joint venture (2) 9,930 (2) 9,930 (2) Long-term debt, including current portion (note 6) Level 2 (608,960 ) (604,434 ) (735,406 ) (723,031 ) Obligations related to finance leases, including current portion (note 8) Level 2 (420,934 ) (451,145 ) (375,289 ) (377,652 ) (1) The fair value of the Company’s interest rate swap agreements and FFAs at September 30, 2019 and December 31, 2018 excludes accrued interest income and expenses which are recorded in accounts receivables and accrued liabilities, respectively, on the unaudited consolidated balance sheets. (2) The advances to its equity-accounted joint venture, together with the Company’s investment in the equity-accounted joint venture, form the net aggregate carrying value of the Company’s interests in the equity-accounted joint venture in these consolidated financial statements. The fair values of the individual components of such aggregate interests as at September 30, 2019 and December 31, 2018 were not determinable.
Summary of Financing Receivables	The following table contains a summary of the Company’s financing receivables by type and the method by which the Company monitors the credit quality of its financing receivables on a quarterly basis. September 30, 2019 December 31, 2018 Class of Financing Receivable Credit Quality Indicator Grade $ $ Advances to equity-accounted joint venture Other internal metrics Performing 9,930 9,930 Total 9,930 9,930

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Summary of Related Party Transactions	Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 $ $ $ $ Vessel operating expenses - technical management fee (i) — (2,800 ) — (8,900 ) Strategic and administrative service fees (ii) (7,437 ) (7,875 ) (23,179 ) (25,204 ) Secondment fees (iii) (21 ) (189 ) (120 ) (548 ) LNG service revenues (iv) (150 ) 72 1,979 344 Technical management fee revenue (v) 169 3,490 596 9,819 Service revenues (vi) 100 343 317 758 (i) The cost of ship management services provided by the Manager has been presented as vessel operating expenses on the Company's consolidated statements of loss. There were no technical management fees paid to a related party for the three and nine months ended September 30, 2019 as the Company elected to receive technical management services for its owned and leased vessels (other than certain former TIL vessels, which are managed by a third party) from its wholly-owned subsidiaries and no longer contracts these services from the Manager. (ii) The Manager’s strategic and administrative service fees have been presented in general and administrative expenses, except for fees related to technical management services, which have been presented in vessel operating expenses on the Company’s consolidated statements of loss. The Company’s executive officers are employees of Teekay or subsidiaries thereof, and their compensation (other than any awards under the Company’s long-term incentive plan described in note 13) is set and paid by Teekay or such other subsidiaries. The Company reimburses Teekay for time spent by its executive officers on the Company’s management matters through the strategic portion of the management fee. (iii) The Company pays secondment fees for services provided by some employees of Teekay. Secondment fees have been presented in general and administrative expenses, except for fees related to technical management services, which have been presented in vessel operating expenses on the Company's consolidated statements of loss. (iv) In November 2016, the Company's ship-to-ship transfer business signed an operational and maintenance subcontract with Teekay LNG Bahrain Operations L.L.C., an entity wholly-owned by TGP, for the Bahrain LNG Import Terminal. The terminal is owned by Bahrain LNG W.I.L., a joint venture for which Teekay LNG Operating L.L.C., an entity wholly-owned by TGP, has a 30% interest. The sub-contract ended in April 2019. (v) The Company receives reimbursements from Teekay, which subcontracts technical management services from the Manager. These reimbursements have been presented in general and administrative expenses on the Company's consolidated statements of loss. (vi) The Company recorded revenue relating to TTOL's administration of certain RSAs and provision of certain commercial services to participants in the arrangements.

Loss Per Share (Tables)

Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Basic and Diluted (Loss) Earnings Per Share	The net loss available for common shareholders and loss per common share are presented in the table below: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2018 September 30, 2019 September 30, 2018 $ $ $ $ Net loss (19,850 ) (17,484 ) (21,710 ) (64,050 ) Weighted average number of common shares - basic 268,990,399 268,558,556 268,887,485 268,470,804 Dilutive effect of stock-based awards — — — — Weighted average number of common shares - diluted 268,990,399 268,558,556 268,887,485 268,470,804 Loss per common share: – Basic (0.07 ) (0.07 ) (0.08 ) (0.24 ) – Diluted (0.07 ) (0.07 ) (0.08 ) (0.24 )

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	9 Months Ended
	Sep. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Total cash, cash equivalents and restricted cash is as follows: As at As at As at As at September 30, 2019 December 31, 2018 September 30, 2018 December 31, 2017 $ $ $ $ Cash and cash equivalents 76,705 54,917 54,361 71,439 Restricted cash – current 2,341 2,153 1,794 1,599 Restricted cash – long-term 3,437 3,437 2,672 2,672 82,483 60,507 58,827 75,710 The Company maintains restricted cash deposits relating to certain FFAs (note 9 ), LNG terminal management and leasing arrangements (note 8 ). Non-cash items related to operating lease right-of-use assets and operating lease liabilities are as follows: For the nine months ended September 30, 2019 September 30, 2018 $ $ Leased assets obtained in exchange for new operating lease liabilities 22,432 —

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements Accounting Pronouncements - Narrative (Details) $ in Thousands	Sep. 30, 2019USD ($)vessel	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets (notes 2 and 8)	$ 23,595		$ 0
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets (notes 2 and 8)		$ 11,000
Variable Interest Entity, Primary Beneficiary [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance Leased Assets, Number of Units | vessel	14

Revenue Revenue - Narrative (De

Revenue Revenue - Narrative (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)vesselcontract	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)vessel
Disaggregation of Revenue [Line Items]
Number of forms of contracts | contract			2
Total revenues	$ 182,304	$ 175,915	$ 617,082	$ 516,039
Number Of Vessels | vessel			3		8
Operating leases, future minimum payments receivable	6,300		$ 6,300		$ 6,300
Time-charter [Member]
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,909	$ 12,326	$ 6,775	$ 51,820
Charters Out
Disaggregation of Revenue [Line Items]
Number Of Vessels | vessel			1		2

Revenue Revenue - Disaggregatio

Revenue Revenue - Disaggregation of revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 182,304	$ 175,915	$ 617,082	$ 516,039
Voyage Charters - Suezmax
Disaggregation of Revenue [Line Items]
Total revenues	85,523	90,267	268,972	243,771
Voyage Charters - Aframax
Disaggregation of Revenue [Line Items]
Total revenues	51,075	29,210	164,381	76,952
Voyage Charters - LR2
Disaggregation of Revenue [Line Items]
Total revenues	23,989	16,712	84,001	40,312
Voyage Charters - Full Service Lightering
Disaggregation of Revenue [Line Items]
Total revenues	12,447	15,858	58,902	70,982
Voyage charter revenues
Disaggregation of Revenue [Line Items]
Total revenues	173,034	152,047	576,256	432,017
Time Charters - Aframax
Disaggregation of Revenue [Line Items]
Total revenues	0	7,784	1,837	31,608
Time Charters - Suezmax
Disaggregation of Revenue [Line Items]
Total revenues	1,909	2,909	4,938	13,063
Time Charters - LR2
Disaggregation of Revenue [Line Items]
Total revenues	0	1,633	0	7,149
Time-charter [Member]
Disaggregation of Revenue [Line Items]
Total revenues	1,909	12,326	6,775	51,820
Ship-to-ship support services, Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	4,649	8,217	17,810	22,452
Commercial management, Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	1,893	2,050	6,219	6,246
LNG terminal management, consultancy and other, Other revenue
Disaggregation of Revenue [Line Items]
Total revenues	819	1,275	10,022	3,504
Other revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 7,361	$ 11,542	$ 34,051	$ 32,202

Segment Reporting - Additional

Segment Reporting - Additional Information (Details)	9 Months Ended
	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Reporting - Schedule of

Segment Reporting - Schedule of Company's Revenue and Income From Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues	$ 182,304	$ 175,915	$ 617,082	$ 516,039
Voyage expenses	(87,726)	(83,048)	(277,733)	(249,974)
Vessel operating expenses	(48,539)	(52,161)	(156,726)	(157,808)
Time-charter hire expenses (note 8)	(10,637)	(4,317)	(30,877)	(14,697)
Depreciation and amortization	(31,536)	(29,595)	(92,059)	(88,598)
General and administrative expenses	(8,739)	(8,747)	(27,412)	(27,939)
Gain on sale of vessel	0	0	0	170
Restructuring charges	0	(213)	0	(1,195)
(Loss) income from operations	(4,873)	(2,166)	32,275	(24,002)
Equity loss	68	(359)	652	265
Operating Segments | Conventional Tanker Segment
Segment Reporting Information [Line Items]
Revenues	176,836	166,423	589,250	490,083
Voyage expenses	(90,943)	(85,575)	(286,322)	(259,079)
Vessel operating expenses	(41,833)	(43,432)	(129,555)	(131,886)
Time-charter hire expenses (note 8)	(9,331)	(2,935)	(26,497)	(10,326)
Depreciation and amortization	(30,634)	(28,532)	(89,422)	(85,171)
General and administrative expenses	(7,955)	(7,985)	(25,030)	(25,385)
Gain on sale of vessel				0
Restructuring charges		0		(152)
(Loss) income from operations	(3,860)	(2,036)	32,424	(21,916)
Equity loss	68	(359)	652	265
Operating Segments | Ship-to-Ship Transfer Segment
Segment Reporting Information [Line Items]
Revenues	8,685	12,019	36,421	35,061
Voyage expenses	0	0	0	0
Vessel operating expenses	(6,706)	(8,729)	(27,171)	(25,922)
Time-charter hire expenses (note 8)	(1,306)	(1,382)	(4,380)	(4,371)
Depreciation and amortization	(902)	(1,063)	(2,637)	(3,427)
General and administrative expenses	(784)	(762)	(2,382)	(2,554)
Gain on sale of vessel				170
Restructuring charges		(213)		(1,043)
(Loss) income from operations	(1,013)	(130)	(149)	(2,086)
Equity loss	0	0	0	0
Inter-segment Adjustment
Segment Reporting Information [Line Items]
Revenues	(3,217)	(2,527)	(8,589)	(9,105)
Voyage expenses	3,217	2,527	8,589	9,105
Vessel operating expenses	0	0	0	0
Time-charter hire expenses (note 8)	0	0	0	0
Depreciation and amortization	0	0	0	0
General and administrative expenses	0	0	0	0
Gain on sale of vessel				0
Restructuring charges		0		0
(Loss) income from operations	0	0	0	0
Equity loss	$ 0	$ 0	$ 0	$ 0

Segment Reporting - Reconciliat

Segment Reporting - Reconciliation of Total Segment Assets to Total Assets Presented in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	$ 2,170,138	$ 2,161,086
Cash and cash equivalents	76,705	54,917	$ 54,361	$ 71,439
Conventional Tanker Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	2,059,873	2,069,854
Ship-to-Ship Transfer Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Consolidated total assets	$ 33,560	$ 36,315

Investments in and Advances t_3

Investments in and Advances to Equity Accounted Joint Venture - Schedule of Investments in and Advances to Equity Accounted Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Investment in and advances to equity accounted investments	$ 26,418	$ 25,766
High-Q Joint Venture
Schedule of Equity Method Investments [Line Items]
Investment in and advances to equity accounted investments	$ 26,418	$ 25,766

Investments in and Advances t_4

Investments in and Advances to Equity Accounted Joint Venture - Additional Information (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)vessel	Dec. 31, 2018USD ($)vessel
Investments in and Advances to Affiliates [Line Items]
Number Of Vessels | vessel	3	8
Long-term Debt, Gross | $	$ 612,877	$ 741,992
High-Q Joint Venture
Investments in and Advances to Affiliates [Line Items]
Ownership percentage	50.00%
High-Q Joint Venture
Investments in and Advances to Affiliates [Line Items]
Number Of Vessels | vessel	1
Long-term Debt, Gross | $	$ 33,500	$ 37,500
Percentage of exposure to loan guarantee	50.00%

Long-Term Debt - Summary of Lon

Long-Term Debt - Summary of Long-Term Debt (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)credit_facility	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8)	$ 63,720,000	$ 156,644,000
Total principal	612,877,000		$ 741,992,000
Less: unamortized discount and debt issuance costs	(3,917,000)		(6,586,000)
Total debt	608,960,000		735,406,000
Less: current portion	(101,295,000)		(106,236,000)
Non-current portion of long-term debt	507,665,000		629,170,000
Term Loans
Debt Instrument [Line Items]
Total principal	248,947,000		323,995,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total principal	$ 363,930,000		417,997,000
Revolving Credit Facilities Due through 2022 [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Number Of Debt Instruments | credit_facility	2
Line of Credit Facility, Remaining Borrowing Capacity	$ 18,400,000		11,800,000
Line of Credit Facility, Maximum Borrowing Capacity	382,300,000		$ 429,800,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Remaining Fiscal Year	3,000,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Two	12,100,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Three	304,800,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Four	$ 62,400,000
Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.30%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Term Loans
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%		2.00%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.75%		2.75%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Term Loans
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.30%		0.30%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%		2.00%

Long-Term Debt - Additional Inf

Long-Term Debt - Additional Information - Revolvers and Term Loans (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)loancredit_facilityvessel	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 31, 2016USD ($)
Debt Instrument [Line Items]
Total principal	$ 612,877,000	$ 741,992,000
Long-term Debt	$ 608,960,000	735,406,000
Secured Debt Two | Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Debt Instrument, Term	6 months
Maintain the greater of free cash liquidity	$ 100,000,000
Minimum liquidity as a percentage of debt	7.50%
Term Loans
Debt Instrument [Line Items]
Total principal	$ 248,947,000	323,995,000
Remaining Secured Debt
Debt Instrument [Line Items]
Debt Instrument, Face Amount	150,400,000	166,400,000
Remaining Secured Debt | Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Maintain the greater of free cash liquidity	$ 50,000,000
Minimum liquidity as a percentage of debt	5.00%
Term Loan Due 2021 | Term Loans
Debt Instrument [Line Items]
Number Of Debt Instruments | credit_facility	3
Total principal	$ 249,000,000	$ 324,000,000
Debt instrument, interest rate, stated percentage	5.40%	5.40%
Maturing in May 2021 | Term Loans
Debt Instrument [Line Items]
Number Of Debt Instruments | loan	2
Revolver 2017
Debt Instrument [Line Items]
Debt Instrument, Face Amount			$ 270,000,000
Long-term Debt	$ 71,200,000	$ 125,300,000
Collateral, number of vessels | vessel	5
Debt Instrument, Collateral Amount	$ 140,000,000	$ 192,600,000
Debt Covenant Minimum Hull Coverage Ratio	125.00%
Actual Hull Coverage Ratio	243.00%	163.00%
Revolver 2017 | Not Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Minimum liquidity covenant requirement	$ 35,000,000
Minimum liquidity as a percentage of consolidated debt covenant requirement	5.00%
2016 Debt Facility
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 391,200,000	$ 450,300,000		$ 894,400,000
Collateral, number of vessels | vessel	29
Debt Instrument, Collateral Amount	$ 930,900,000	$ 972,500,000
Debt Covenant Minimum Hull Coverage Ratio	125.00%
Actual Hull Coverage Ratio	192.00%	137.00%
2016 Debt Facility | Not Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Minimum liquidity covenant requirement	$ 35,000,000
Minimum liquidity as a percentage of consolidated debt covenant requirement	5.00%
Remaining Secured Debt | Term Loans
Debt Instrument [Line Items]
Number Of Debt Instruments | credit_facility	2
Collateral, number of vessels | vessel	6
Term Loan Due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 98,500,000
Minimum [Member]
Debt Instrument [Line Items]
Percentage of margin	0.30%
Minimum [Member] | Revolver 2017 | Not Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Debt Instrument, Term	6 months
Minimum [Member] | 2016 Debt Facility | Not Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Debt Instrument, Term	6 months
Maximum
Debt Instrument [Line Items]
Percentage of margin	3.50%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member] | Term Loans
Debt Instrument [Line Items]
Percentage of margin	0.30%	0.30%
London Interbank Offered Rate (LIBOR) [Member] | Maximum | Term Loans
Debt Instrument [Line Items]
Percentage of margin	2.00%	2.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total principal	$ 363,930,000	$ 417,997,000
Revolving Credit Facility [Member] | Revolving Credit Facilities Due through 2022 [Member]
Debt Instrument [Line Items]
Number Of Debt Instruments | credit_facility	2
Line of Credit Facility, Maximum Borrowing Capacity	$ 382,300,000	429,800,000
Line of Credit Facility, Remaining Borrowing Capacity	18,400,000	$ 11,800,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Remaining Fiscal Year	3,000,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Two	12,100,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Three	304,800,000
Long-term Debt, Maturities, Revolving Credit Facility, Decrease in Amount Available Year Four	62,400,000
Revolving Credit Facility [Member] | 2016 Debt Facility
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 292,700,000
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of margin	2.00%	2.00%
Revolving Credit Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum
Debt Instrument [Line Items]
Percentage of margin	2.75%	2.75%
Remaining Secured Debt | Minimum [Member] | Guaranteed By Teekay Corporation
Debt Instrument [Line Items]
Debt Instrument, Term	6 months

Long Term Debt - Additional Inf

Long Term Debt - Additional Information - Other (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Debt Instruments [Abstract]
Weighted-average effective interest rate	4.20%	4.60%
Aggregate annual long-term principal repayments, 2019	$ 25.4
Aggregate annual long-term principal repayments, 2020	101.8
Aggregate annual long-term principal repayments, 2021	426.6
Aggregate annual long-term principal repayments, 2022	$ 59.1

Long-Term Debt Long-Term Debt s

Long-Term Debt Long-Term Debt sale-leaseback (Details) $ in Thousands	1 Months Ended			9 Months Ended		12 Months Ended
	May 31, 2019vessel	Nov. 30, 2018vessel	Sep. 30, 2018vessel	Sep. 30, 2019USD ($)vessel	Sep. 30, 2018USD ($)	Dec. 31, 2018vessel
Debt Instrument [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $				$ 63,720	$ 156,644
Number Of Vessels				3		8
Finance Lease Obligations [Member] | May 2019 Sale Leaseback [Member]
Debt Instrument [Line Items]
Number Of Vessels	2
Finance Lease Obligations [Member] | September 2018 Sale Leaseback [Member]
Debt Instrument [Line Items]
Number Of Vessels			6
Finance Lease Obligations [Member] | November 2018 Sale leaseback Transaction [Member]
Debt Instrument [Line Items]
Number Of Vessels		4

Leases Finance Lease Obligation

Leases Finance Lease Obligation (Details) $ in Thousands	1 Months Ended				9 Months Ended		12 Months Ended
	May 31, 2019USD ($)vessel	Nov. 30, 2018USD ($)vessel	Sep. 30, 2018USD ($)vessel	Jul. 31, 2017USD ($)vessel	Sep. 30, 2019USD ($)vessel	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)vessel
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $					$ 63,720	$ 156,644
Number Of Vessels					3		8
Finance Lease, Weighted Average Discount Rate, Percent					7.70%		7.50%
Total obligations related to finance leases | $					$ 420,934		$ 375,289
Current obligations related to finance leases (note 8) | $					24,875		20,896
Finance Lease, Liability, Noncurrent | $					$ 396,059		$ 354,393
May 2019 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					90.00%
Actual Hull Coverage Ratio					108.00%		0.00%
Debt Covenant Minimum Hull Coverage Ratio					75.00%
Debt Covenant Minimum Hull Coverage Ratio, Year 2					78.00%
Maintain 80% Hull Coverage Ratio for the Third & Fourth Year					80.00%
November 2018 Sale leaseback Transaction [Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Maintain 100% Hull Overage Ratio					100.00%
November 2018 Sale leaseback Transaction [Member] | Suezmax, Aframax and LR2 Sale Leaseback [Member]
Finance Leased Assets [Line Items]
Actual Hull Coverage Ratio					153.00%		122.00%
July 2017 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					100.00%
Actual Hull Coverage Ratio					121.00%		101.00%
Debt Covenant Minimum Hull Coverage Ratio, Years 1, 2 and 3					90.00%
September 2018 Sale Leaseback [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					90.00%
Actual Hull Coverage Ratio					113.00%		91.00%
Debt Covenant Minimum Hull Coverage Ratio					75.00%
Debt Covenant Minimum Hull Coverage Ratio, Year 2					78.00%
Maintain 80% Hull Coverage Ratio for the Third & Fourth Year					80.00%
Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Number of Lessors					16
Finance Lease Obligations [Member] | May 2019 Sale Leaseback [Member]
Finance Leased Assets [Line Items]
Number Of Vessels	2
Finance Lease Obligations [Member] | May 2019 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $	$ 63,700
Number Of Vessels	2				2
Finance Lease Obligations [Member] | November 2018 Sale leaseback Transaction [Member]
Finance Leased Assets [Line Items]
Number Of Vessels		4
Finance Lease Obligations [Member] | November 2018 Sale leaseback Transaction [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Number Of Vessels		2
Finance Lease Obligations [Member] | November 2018 Sale leaseback Transaction [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Number Of Vessels		1
Finance Lease Obligations [Member] | November 2018 Sale leaseback Transaction [Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $		$ 84,700
Number Of Vessels		4			4
Finance Lease Obligations [Member] | July 2017 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $				$ 153,000
Number Of Vessels				4	4
Finance Lease Obligations [Member] | September 2018 Sale Leaseback [Member]
Finance Leased Assets [Line Items]
Number Of Vessels			6
Finance Lease Obligations [Member] | September 2018 Sale Leaseback [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels (note 8) | $			$ 156,600
Number Of Vessels			6		6
Option to Purchase July 2020- Nov 2021[Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Number Of Vessels					16
Variable Interest Entity, Primary Beneficiary [Member]
Finance Leased Assets [Line Items]
Number of Lessors					14

Leases - Additional Information

Leases - Additional Information (Details)	1 Months Ended				9 Months Ended		12 Months Ended
	May 31, 2019USD ($)vessel	Nov. 30, 2018USD ($)vessel	Sep. 30, 2018USD ($)vessel	Jul. 31, 2017USD ($)vessel	Sep. 30, 2019USD ($)vessel	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)vessel
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels | $					$ 63,720,000	$ 156,644,000
Number Of Vessels					3		8
Finance Lease, Weighted Average Discount Rate, Percent					7.70%		7.50%
LR2 Tankers [Member]
Finance Leased Assets [Line Items]
Number Of Vessels					2
Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Finance Lease, Liability, Payment, Due | $					$ 615,900,000		$ 557,100,000
Finance Lease, Liability, Undiscounted Excess Amount | $					$ 195,000,000		$ 181,800,000
Aframax Tanker
Finance Leased Assets [Line Items]
Number Of Vessels Obligated to Purchase | $					6
Suezmax Tankers
Finance Leased Assets [Line Items]
Number Of Vessels Obligated to Purchase | $					2
Minimum [Member]
Finance Leased Assets [Line Items]
Sale Leaseback Transaction, Lease Terms					P9Y
Maximum
Finance Leased Assets [Line Items]
Sale Leaseback Transaction, Lease Terms					P12Y
Option to Purchase July 2020- Nov 2021[Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Number Of Vessels					16
Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Number of Lessors					16
Finance Lease Obligations [Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Minimum liquidity covenant requirement | $					$ 35,000,000
Minimum liquidity as a percentage of consolidated debt covenant requirement					5.00%
Finance Lease Obligations [Member] | Minimum [Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Debt Instrument, Term					6 months
July 2017 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					100.00%
Actual Hull Coverage Ratio					121.00%		101.00%
July 2017 Sale Leaseback [Member] | Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Period Required to Maintain 90% Hull Coverage Ratio					three
July 2017 Sale Leaseback [Member] | Finance Lease Obligations [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels | $				$ 153,000,000
Number Of Vessels				4	4
September 2018 Sale Leaseback [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Maintain 78% Hull Coverage Ratio for the Second Year					75.00%
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					90.00%
Actual Hull Coverage Ratio					113.00%		91.00%
Debt Covenant Minimum Hull Coverage Ratio, Year 2					78.00%
September 2018 Sale Leaseback [Member] | Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Number Of Vessels			6
September 2018 Sale Leaseback [Member] | Finance Lease Obligations [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels | $			$ 156,600,000
Number Of Vessels			6		6
November 2018 Sale leaseback Transaction [Member] | Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Number Of Vessels		4
November 2018 Sale leaseback Transaction [Member] | Finance Lease Obligations [Member] | LR2 Tankers [Member]
Finance Leased Assets [Line Items]
Number Of Vessels		1
November 2018 Sale leaseback Transaction [Member] | Finance Lease Obligations [Member] | Suezmax, Aframax and LR2 Vessels [Member]
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels | $		$ 84,700,000
Number Of Vessels		4			4
November 2018 Sale leaseback Transaction [Member] | Finance Lease Obligations [Member] | Aframax Tanker
Finance Leased Assets [Line Items]
Number Of Vessels		2
November 2018 Sale leaseback Transaction [Member] | Finance Lease Obligations [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Number Of Vessels		1
May 2019 Sale Leaseback [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Maintain 78% Hull Coverage Ratio for the Second Year					75.00%
Debt Covenant Minimum Hull Coverage Ratio, Thereafter					90.00%
Actual Hull Coverage Ratio					108.00%		0.00%
Debt Covenant Minimum Hull Coverage Ratio, Year 2					78.00%
May 2019 Sale Leaseback [Member] | Finance Lease Obligations [Member]
Finance Leased Assets [Line Items]
Number Of Vessels	2
May 2019 Sale Leaseback [Member] | Finance Lease Obligations [Member] | Suezmax Tankers
Finance Leased Assets [Line Items]
Proceeds from financing related to sales and leaseback of vessels | $	$ 63,700,000
Number Of Vessels	2				2
Variable Interest Entity, Primary Beneficiary [Member]
Finance Leased Assets [Line Items]
Number of Lessors					14

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Details) - Suezmax, Aframax and LR2 Vessels [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finance Leased Assets [Line Items]
Finance Lease, Liability, Payment, Due	$ 615,900	$ 557,100
Finance Lease, Liability, Undiscounted Excess Amount	195,000	181,800
Finance Lease, Liability, Payments, Remainder of Fiscal Year	14,242	47,962
Finance Lease, Liability, Payments, Due Year Two	56,364	47,373
Finance Lease, Liability, Payments, Due Year Three	56,202	47,237
Finance Lease, Liability, Payments, Due Year Four	56,193	47,230
Finance Lease, Liability, Payments, Due Year Five	56,184	47,222
Finance Lease, Liability, Payments, Due after Year Five	$ 376,749	$ 320,064

Leases Operating Leases (Detail

Leases Operating Leases (Details) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)vessel	Dec. 31, 2018USD ($)vessel
Operating Leased Assets [Line Items]
Operating lease right-of-use assets (notes 2 and 8)	$ 23,595	$ 23,595	$ 0
Lessee, Operating Lease, Liability, Payments, Due Year Two	30,362	$ 30,362
Number Of Vessels | vessel		3	8
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	7,797	$ 7,797
Lessee, Operating Lease, Liability, Payments, Due Year Three	5,900	5,900
Lessee, Operating Lease, Liability, Payments, Due	44,059	44,059
Operating Lease, Liability	23,595	23,595
Time Charter-in Hire Expense	6,400	17,400
Time Charter Hire Expense Lease Component	$ 3,600	$ 9,700
Operating Lease, Weighted Average Remaining Lease Term	1 year 6 months	1 year 6 months
Operating Lease, Weighted Average Discount Rate, Percent	5.58%	5.58%
Charter Contract Extension, Period		1 year
Time Charter Hire Expense Non Lease Component	$ 2,800	$ 7,700
Lease [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Year Two	16,956	16,956
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	4,352	4,352
Lessee, Operating Lease, Liability, Payments, Due Year Three	3,315	3,315
Lessee, Operating Lease, Liability, Payments, Due	24,623	24,623
Non-lease Component [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Year Two	13,406	13,406
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	3,445	3,445
Lessee, Operating Lease, Liability, Payments, Due Year Three	2,585	2,585
Lessee, Operating Lease, Liability, Payments, Due	19,436	19,436
Time-charter [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Year Two	2,700	2,700
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year	4,300	4,300
Lease [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(1,028)	(1,028)
LR2 Tankers [Member]
Operating Leased Assets [Line Items]
Operating lease right-of-use assets (notes 2 and 8)	$ 14,600	$ 14,600
Number Of Vessels | vessel		2
Charter-In Period	24 months	24 months
Aframax Tanker
Operating Leased Assets [Line Items]
Operating lease right-of-use assets (notes 2 and 8)	$ 7,800	$ 7,800
Voyage Charters - Full Service Lightering [Member]
Operating Leased Assets [Line Items]
Number Of Vessels | vessel			3
Time-Charter Hire Expense [Member]
Operating Leased Assets [Line Items]
Short-term Lease, Cost	$ 4,200	$ 13,400
Time-charter [Member]
Operating Leased Assets [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Year Two			$ 23,500
Operating Leases, Future Minimum Payments, Remainder of Fiscal Year			36,900
Lessee, Operating Lease, Liability, Payments, Due Year Three			$ 2,000

Derivative Instruments - Summar

Derivative Instruments - Summary of Interest Rate Swap Positions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Derivative [Line Items]
Realized gains	$ 1,048	$ 592	$ 2,788	$ 1,438
Current portion of derivative assets (note 9)	1,878		1,878		$ 2,905
LIBOR-Based Debt:
Derivative Asset, Noncurrent	82		82		2,973
Accrued Liabilities (Receivables), Current	365		365		419
Derivative liabilities (note 9)	(49)		(49)		0
Derivative Liability, Current	0		$ 0		(57)
Minimum [Member]
LIBOR-Based Debt:
Debt Instrument, Basis Spread on Variable Rate			0.30%
Maximum
LIBOR-Based Debt:
Debt Instrument, Basis Spread on Variable Rate			3.50%
Interest rate swap agreements
Derivative [Line Items]
Realized gains	613	711	$ 2,395	1,575
Current portion of derivative assets (note 9)	833		833		2,905
LIBOR-Based Debt:
Derivative Asset, Noncurrent	82		82		2,973
Accrued Liabilities (Receivables), Current	365		365		422
Derivative liabilities (note 9)	(49)		(49)		0
Derivative Liability, Current	0		0		0
U.S. Dollar-denominated interest rate swap 1
Derivative [Line Items]
Derivative, Notional Amount	$ 57,852		$ 57,852
LIBOR-Based Debt:
Remaining Term			1 year 3 months 18 days
Fixed Interest Rate	1.46%		1.46%
United States Dollar Denominated Interest Rate Swaps Two [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 150,000		$ 150,000
LIBOR-Based Debt:
Remaining Term			1 year 3 months 18 days
Fixed Interest Rate	1.55%		1.55%
United States Dollar Denominated Interest Rate Swaps Three [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 50,000		$ 50,000
LIBOR-Based Debt:
Remaining Term			1 year 3 months 18 days
Fixed Interest Rate	1.16%		1.16%
Freight Forward Agreements [Member]
Derivative [Line Items]
Realized gains	$ 435	$ (119)	$ 393	$ (137)
Current portion of derivative assets (note 9)	1,045		1,045		0
LIBOR-Based Debt:
Derivative Asset, Noncurrent	0		0		0
Accrued Liabilities (Receivables), Current	0		0		3
Derivative liabilities (note 9)	0		0		0
Derivative Liability, Current	$ 0		$ 0		$ 57

Derivative Instruments - Additi

Derivative Instruments - Additional Information (Details)	9 Months Ended
	Sep. 30, 2019
Maximum
Derivative [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Minimum [Member]
Derivative [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.30%

Derivative Instruments - Locati

Derivative Instruments - Location and Fair Value Amounts of Derivative Instruments (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Current portion of derivative assets	$ 1,878	$ 2,905
Accounts receivable (Accrued liabilities)	(365)	(419)
United States Dollar Denominated Interest Rate Swaps One [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 57,852
Fixed Interest Rate	1.46%
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	$ 167
Derivative Liability	$ 0
Remaining Term	1 year 3 months 18 days
Interest rate swap agreements
Derivatives, Fair Value [Line Items]
Current portion of derivative assets	$ 833	2,905
Accounts receivable (Accrued liabilities)	(365)	(422)
Forward freight agreements
Derivatives, Fair Value [Line Items]
Current portion of derivative assets	1,045	0
Accounts receivable (Accrued liabilities)	0	$ (3)
United States Dollar Denominated Interest Rate Swaps Two [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 150,000
Fixed Interest Rate	1.55%
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	$ 383
Derivative Liability	$ 49
Remaining Term	1 year 3 months 18 days
United States Dollar Denominated Interest Rate Swaps Three [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 50,000
Fixed Interest Rate	1.16%
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	$ 365
Derivative Liability	$ 0
Remaining Term	1 year 3 months 18 days
Maximum [Member]
Derivatives, Fair Value [Line Items]
Debt Instrument, Basis Spread on Variable Rate	3.50%

Derivative Instruments - Gain (

Derivative Instruments - Gain (Loss) for Derivative Instruments Not Designated or Qualifying as Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
Realized gains	$ 1,048	$ 592	$ 2,788	$ 1,438
Unrealized (losses) gains	405	4	(3,960)	3,287
Total	1,453	596	(1,172)	4,725
Interest rate swap agreements
Derivative [Line Items]
Realized gains	613	711	2,395	1,575
Unrealized (losses) gains	(541)	13	(5,010)	3,262
Total	72	724	(2,615)	4,837
Forward freight agreements
Derivative [Line Items]
Realized gains	435	(119)	393	(137)
Unrealized (losses) gains	946	(9)	1,050	25
Total	$ 1,381	$ (128)	$ 1,443	$ (112)

Other Income - Components of Ot

Other Income - Components of Other Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Liabilities Disclosure [Abstract]
Foreign exchange gain	$ 918	$ 1,251	$ 1,100	$ 6,025
Other income	15	0	82	49
Total	$ 933	$ 1,251	$ 1,182	$ 6,074

Freight Tax and Other Tax Exp_3

Freight Tax and Other Tax Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019	Jan. 01, 2018
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits	$ 36,240	$ 29,912	$ 32,059	$ 26,054
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	2,067	2,099
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	2,114	1,852
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	$ 0	$ (93)

Financial Instruments - Summary

Financial Instruments - Summary of Fair Value and Carrying Value of Assets and Liabilities Measured on Recurring and Non-recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt	$ (50,000)	$ 0
Cash, cash equivalents and restricted cash	82,483	60,507	$ 58,827	$ 75,710
Derivative assets	82	2,973
Advances to equity-accounted for joint venture	9,930	9,930
Long-term debt, including current portion (note 6)	(608,960)	(735,406)
Total obligations related to finance leases	(420,934)	(375,289)
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt	(50,000)
Long-term debt, including current portion (note 6)	(604,434)	(723,031)
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Interest rate swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	866	5,878
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Forward freight agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1,045	57
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	82,483	60,507
Estimate of Fair Value Measurement [Member] | Fair Value, Recurring [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt		0
Total obligations related to finance leases	(451,145)	(377,652)
Reported Value Measurement [Member] | Fair Value, Recurring [Member] | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash, cash equivalents and restricted cash	82,483	60,507
Reported Value Measurement [Member] | Fair Value, Recurring [Member] | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term Debt	(50,000)	0
Advances to equity-accounted for joint venture	9,930	9,930
Long-term debt, including current portion (note 6)	(608,960)	(735,406)
Total obligations related to finance leases	(420,934)	(375,289)
Reported Value Measurement [Member] | Fair Value, Recurring [Member] | Level 2 | Interest rate swap agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value	866	5,878
Reported Value Measurement [Member] | Fair Value, Recurring [Member] | Level 2 | Forward freight agreements
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	$ 1,045	$ 57

Financial Instruments - Summa_2

Financial Instruments - Summary of Financing Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Advances to equity-accounted for joint venture	$ 9,930	$ 9,930
Other internal metrics | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Advances to equity-accounted for joint venture	$ 9,930	$ 9,930

Capital Stock and Stock-Based_2

Capital Stock and Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)			100,000,000		100,000,000		100,000,000
Preferred stock, par value (usd per share)			$ 0.01		$ 0.01
Common stock, shares authorized (in shares)			585,000,000		585,000,000		585,000,000
Preferred stock, shares issued (in shares)			0		0		0
Stock based compensation expense			$ 0.2	$ 0.2	$ 0.9	$ 0.8
Restricted Stock [Member]
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period					400,000		300,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value					$ 0.5		$ 0.3
2007 Long-Term Incentive Plan | Stock Options
Class of Stock [Line Items]
Expected volatility rate					48.70%		48.70%
2007 Long-Term Incentive Plan | Non Management Directors | Stock Options
Class of Stock [Line Items]
Stock options granted during period (in shares)	500,000	500,000
Exercise price of stock options granted (usd per share)	$ 1	$ 1.22
Term of stock options (in years)					10 years
2007 Long-Term Incentive Plan | Officer | Stock Options
Class of Stock [Line Items]
Stock options granted during period (in shares)	1,400,000						700,000
Exercise price of stock options granted (usd per share)	$ 1						$ 1.22
Term of stock options (in years)					10 years
Vesting period (in years)					3 years
Weighted-average grant date fair value of stock options granted (usd per share)					$ 0.35		$ 0.35
Expected life (in years)					5 years		5 years
Dividend yield					3.00%		5.50%
Risk-free interest rate					2.40%		2.60%
Period of historical sata used to calculate expected volatility in year					5 years
2007 Long-Term Incentive Plan | Officers and Certain Subsidiaries Employees | Restricted Stock Units
Class of Stock [Line Items]
Vesting period (in years)					3 years
Common stock, granted (in shares)	600,000						800,000
Common stock aggregate values, granted	$ 0.6						$ 0.9
Conversion basis (in shares)					1
Class A
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			485,000,000		485,000,000		485,000,000
Common Stock, Par or Stated Value Per Share			$ 0.01		$ 0.01
Common Stock, Voting Rights					1
Common stock, shares issued (in shares)			232,000,000		232,000,000		231,600,000
Class A | Restricted Stock Units
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues					300,000		200,000
Class A | 2007 Long-Term Incentive Plan | Non Management Directors
Class of Stock [Line Items]
Shares issued in period (in shares)	159,375
Stock issued in period, gross	$ 0.2
Class B
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			100,000,000		100,000,000		100,000,000
Common Stock, Par or Stated Value Per Share			$ 0.01		$ 0.01
Common Stock, Voting Rights					5
Maximum percentage of voting power					49.00%
Common stock, shares issued (in shares)			37,000,000		37,000,000		37,000,000
General and Administrative Expense | Class A | Non Management Director [Member]
Class of Stock [Line Items]
Stock based compensation expense					$ 0.3	$ 0.4

Related Party Transactions - Su

Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Nov. 30, 2016
Related Party Transaction [Line Items]
Vessel operating expenses	$ (48,539,000)	$ (52,161,000)	$ (156,726,000)	$ (157,808,000)
Strategic and administrative service fees	(7,437,000)	(7,875,000)	(23,179,000)	(25,204,000)
Revenues	182,304,000	175,915,000	617,082,000	516,039,000
Due to Affiliate, Current	1,241,000		1,241,000		$ 18,570,000
Due from affiliates (note 14c)	1,634,000		$ 1,634,000		39,663,000
Pool Management Fees As Percentage Of Gross Revenue			1.25%
Pool receivable from affiliates, net (note 14d)	562,000		$ 562,000		56,549,000
Teekay LNG Operating L.L.C. | Bahrain LNG W.I.L.
Related Party Transaction [Line Items]
Ownership percentage						30.00%
Revenue Sharing Arrangements [Member]
Related Party Transaction [Line Items]
Due from affiliates (note 14c)	0		0		34,900,000
RSA Participants [Member]
Related Party Transaction [Line Items]
Pool receivable from affiliates, net (note 14d)	600,000		600,000		56,500,000
Payable to Manager [Member]
Related Party Transaction [Line Items]
Due to Affiliate, Current	7,800,000		7,800,000		$ 7,600,000
Vessel operating expenses - technical management fee
Related Party Transaction [Line Items]
Vessel operating expenses	0	(2,800,000)	0	(8,900,000)
Secondment fees
Related Party Transaction [Line Items]
Strategic and administrative service fees	(21,000)	(189,000)	(120,000)	(548,000)
LNG terminal services revenue
Related Party Transaction [Line Items]
Revenues	(150,000)	72,000	1,979,000	344,000
Technical management fee revenues
Related Party Transaction [Line Items]
Revenues	169,000	3,490,000	596,000	9,819,000
Service revenues
Related Party Transaction [Line Items]
Revenues	100,000	$ 343,000	317,000	$ 758,000
Minimum [Member]
Related Party Transaction [Line Items]
Pool Management Fees Fixed Amount Per Day	275		275
Maximum [Member]
Related Party Transaction [Line Items]
Pool Management Fees Fixed Amount Per Day	$ 350		$ 350

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Working capital advanced to Pool Managers	$ 1,634,000		$ 1,634,000		$ 39,663,000
Revenue Sharing Arrangements
Related Party Transaction [Line Items]
Working capital advanced to Pool Managers	0		0		$ 34,900,000
Aframax Tanker | RSA Participants [Member] | Vessels Hire
Related Party Transaction [Line Items]
Amounts of transaction	$ 100,000	$ 3,300,000	$ 7,500,000	$ 19,100,000

Sales of Vessels (Details)

Sales of Vessels (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)vessel
Property, Plant and Equipment [Line Items]
Gain on sale of vessel (note 16) | $	$ 0	$ 0	$ 0	$ 170
Voyage Charters - Full Service Lightering [Member]
Property, Plant and Equipment [Line Items]
Number Of Vessels Sold | vessel				1

(Loss) Earnings Per Share - Bas

(Loss) Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net loss	$ (19,850)	$ (14,307)	$ 12,447	$ (17,484)	$ (27,413)	$ (19,153)	$ (21,710)	$ (64,050)
Weighted average number of common shares – basic (in shares)	268,990,399			268,558,556			268,887,485	268,470,804
Dilutive effect of stock-based awards (in shares)	0			0			0	0
Weighted average number of common shares – diluted (in shares)	268,990,399			268,558,556			268,887,485	268,470,804
Loss per common share:
– Basic (usd per share)	$ (0.07)			$ (0.07)			$ (0.08)	$ (0.24)
– Diluted (usd per share)	$ (0.07)			$ (0.07)			$ (0.08)	$ (0.24)

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Elements [Abstract]
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 22,432	$ 0
Cash and cash equivalents	76,705	54,361	$ 54,917	$ 71,439
Restricted cash – current (note 17)	2,341	1,794	2,153	1,599
Restricted cash – long-term (note 17)	3,437	2,672	3,437	2,672
Cash and cash equivalents and restricted cash	$ 82,483	$ 58,827	$ 60,507	$ 75,710

Subsequent Events (Details)

Subsequent Events (Details) - $ / shares	Nov. 01, 2019	Sep. 30, 2019	Dec. 31, 2018
Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, shares issued (in shares)	1
Class A
Subsequent Event [Line Items]
Common Stock, Par or Stated Value Per Share		$ 0.01
Common stock, shares issued (in shares)		232,000,000	231,600,000
Class A | Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Par or Stated Value Per Share	$ 0.01
Common stock, shares issued (in shares)	232,000,000
Class B
Subsequent Event [Line Items]
Common Stock, Par or Stated Value Per Share		$ 0.01
Common stock, shares issued (in shares)		37,000,000	37,000,000
Class B | Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Par or Stated Value Per Share	$ 0.01
Common stock, shares issued (in shares)	37,000,000
Reverse Stock Split [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, shares issued (in shares)	8
Class B | Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, shares issued (in shares)	4,600,000
Class A | Subsequent Event [Member]
Subsequent Event [Line Items]
Common stock, shares issued (in shares)	29,000,000