International Seaways (INSW) 10-K 12 Mar 18 2017 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 07, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	International Seaways, Inc.
Entity Central Index Key	1,679,049
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		29,107,398
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,017
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 345,830,880

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash and cash equivalents	$ 60,027	$ 92,001
Voyage receivables, including unbilled of $54,701 and $61,416	58,187	66,918
Other receivables	4,411	5,302
Inventories	3,270	1,338
Prepaid expenses and other current assets	5,897	5,350
Total Current Assets	131,792	170,909
Restricted cash	10,579
Vessels and other property, less accumulated depreciation	1,104,727	1,100,050
Vessel held for sale, net	5,108
Deferred drydock expenditures, net	30,528	30,557
Total Vessels, Deferred Drydock and Other Property	1,140,363	1,130,607
Investments in and advances to affiliated companies	378,894	358,681
Other assets	2,856	2,324
Total Assets	1,664,484	1,662,521
Current Liabilities:
Accounts payable, accrued expenses and other current liabilities	22,805	38,237
Payable to OSG	367	683
Current installments of long-term debt	24,063	6,183
Total Current Liabilities	47,235	45,103
Long-term debt	528,874	433,468
Other liabilities	2,721	4,438
Total Liabilities	578,830	483,009
Commitments and contingencies
Equity:
Capital - 100,000,000 no par value shares authorized; 29,089,865 and 29,189,454 shares issued and outstanding	1,306,606	1,306,236
(Accumulated deficit)/retained earnings	(180,545)	(74,457)
Stockholders Equity Subtotal	1,126,061	1,231,779
Accumulated other comprehensive loss	(40,407)	(52,267)
Total Equity	1,085,654	1,179,512
Total Liabilities and Equity	$ 1,664,484	$ 1,662,521

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position Parenthetical [Abstract]
Unbilled contracts receivable (in dollars)	$ 54,701	$ 61,416
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares, issued	29,089,865	29,189,454
Common stock, shares, outstanding	29,089,865	29,189,454

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Shipping Revenues:
Pool revenues, including $39,572 in 2017, $37,481 in 2016, and $45,372 in 2015 from companies accounted for by the equity method	$ 177,347	$ 246,196	$ 360,218
Time and bareboat charter revenues	55,106	95,484	52,092
Voyage charter revenues	57,648	56,639	85,324
Shipping revenues	290,101	398,319	497,634
Operating Expenses:
Voyage expenses	15,106	13,274	21,844
Vessel expenses	141,235	141,944	143,925
Charter hire expenses	41,700	37,411	36,802
Depreciation and amortization	78,853	79,885	81,653
General and administrative	24,736	31,618	41,516
Third-party debt modification costs	9,240
Separation and transition costs	604	9,043
Technical management transition costs			39
Loss/(gain) on disposal of vessels and other property, including impairments	86,855	79,203	(4,459)
Total Operating Expenses	398,329	392,378	321,320
Income from Vessel Operations	(108,228)	5,941	176,314
Equity in Income of Affiliated Companies	48,966	16,849	45,559
Operating Income	(59,262)	22,790	221,873
Other (Expense)/Income	(6,344)	(966)	66
Income before Interest Expense, Reorganization Items and Income Taxes	(65,606)	21,824	221,939
Interest Expense	(40,438)	(39,476)	(42,970)
Income/(Loss) before Reorganization Items and Income Taxes	(106,044)	(17,652)	178,969
Reorganization items, net		(131)	(5,659)
Income/(Loss) before Income Taxes	(106,044)	(17,783)	173,310
Income Tax Provision	(44)	(440)	(140)
Net Income/(Loss)	$ (106,088)	$ (18,223)	$ 173,170
Weighted Average Number of Common Shares Outstanding:
Basic and Diluted (in shares)	29,159,440	29,157,992	29,157,387
Per Share Amounts:
Basic and Diluted net income (in dollars per share)	$ (3.64)	$ (0.62)	$ 5.94

CONSOLIDATED STATEMENTS OF OPE5

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Pool revenues, received from companies accounted for by the equity method	$ 39,572	$ 37,481

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net (Loss)/Income	$ (106,088)	$ (18,223)	$ 173,170
Other Comprehensive Income/(Loss), net of tax:
Net change in unrealized losses on cash flow hedges	11,328	13,129	7,910
Foreign currency translation adjustment		42	(13)
Defined benefit pension and other postretirement benefit plans:
Net change in unrecognized prior service costs	(31)	294	118
Net change in unrecognized actuarial losses	563	(1,608)	2,234
Other Comprehensive Income/(Loss), net of tax	11,860	11,857	10,249
Comprehensive Income/(Loss)	$ (94,228)	$ (6,366)	$ 183,419

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net (Loss)/Income	$ (106,088)	$ (18,223)	$ 173,170
Items included in net (loss)/income not affecting cash flows:
Depreciation and amortization	78,853	79,885	81,653
Loss on write-down of vessels	88,408	79,242
Amortization of debt discount and other deferred financing costs	6,423	6,643	5,835
Deferred financing costs write-off	7,020	5,097
Direct and allocated stock compensation, non-cash	3,808	2,841	2,811
Undistributed earnings of affiliated companies	(49,427)	(17,816)	(38,666)
Allocated reorganization items, non-cash		131	5,659
Other - net	131	517	(41)
Items included in net income/(loss) related to investing and financing activities:
Gain on disposal of vessels and other property	(1,553)	(39)	(4,459)
Allocated general and administrative expenses recorded as capital contributions		1,146	954
Discount on repurchase of debt		(3,755)
Payments for drydocking	(21,396)	(9,258)	(20,728)
Deferred financing costs paid for loan modification		(8,273)	(5,545)
Changes in operating assets and liabilities:
Decrease in receivables	8,730	8,033	13,398
(Decrease)/increase in payable to OSG	(316)	(10,667)	5,733
Decrease in deferred revenue	(4,730)	4,421
Net change in inventory, prepaid expenses and other current assets, accounts payable, accrued expenses and other current and long-term liabilities	(13,688)	(3,131)	2,965
Net cash provided by/(used in) operating activities	(3,825)	116,794	222,739
Cash Flows from Investing Activities:
(Increase)/decrease in restricted cash	(10,579)	8,989	61,104
Expenditures for vessels and vessel improvements	(173,535)	(1,988)	(964)
Proceeds from disposal of vessels and other property	18,344		17,058
Expenditures for other property	(406)	(907)
Investments in and advances to affiliated companies	(731)	(987)	(153)
Repayments of advances from affiliated companies	40,750	18,500	37,500
Other - net			(382)
Net cash (used in)/provided by investing activities	(126,157)	23,607	114,163
Cash Flows from Financing Activities:
Issuance of debt, net of issuance and deferred financing costs	614,933
Payments on debt	(54,983)	(90,065)	(6,284)
Extinguishment of debt	(458,416)	(65,167)
Dividend payments to OSG		(202,000)	(200,000)
Repurchases of common stock	(3,177)
Cash paid to tax authority upon vesting of stock-based compensation	(349)	(26)
Net cash (used in)/provided by financing activities	98,008	(357,258)	(206,284)
Net (decrease)/increase in cash and cash equivalents	(31,974)	(216,857)	130,618
Cash and cash equivalents at beginning of year	92,001	308,858	178,240
Cash and cash equivalents at end of year	$ 60,027	$ 92,001	$ 308,858

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Paid-in Additional Capital [Member]	Retained Earnings / (Accumulated deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Balance at Dec. 31, 2014	$ 1,464,428	$ 888	$ (74,373)	$ 1,390,943
Net (Loss)/Income		173,170		173,170
Other comprehensive income (loss)			10,249	10,249
Capital contribution of Former Parent, net	9,424			9,424
Dividends	(118,523)	(81,477)		(200,000)
Balance at Dec. 31, 2015	1,355,329	92,581	(64,124)	1,383,786
Net (Loss)/Income		(18,223)		(18,223)
Other comprehensive income (loss)			11,857	11,857
Capital contribution of Former Parent, net	3,797			3,797
Dividends	(53,185)	(148,815)		(202,000)
Compensation relating to restricted stock awards	40			40
Compensation relating to restricted stock units awards	184			184
Compensation relating to stock options	71			71
Balance at Dec. 31, 2016	1,306,236	(74,457)	(52,267)	1,179,512
Net (Loss)/Income		(106,088)		(106,088)
Other comprehensive income (loss)			11,860	11,860
Forfeitures of vested restricted stock awards	(261)			(261)
Compensation relating to restricted stock awards	841			841
Compensation relating to restricted stock units awards	2,141			2,141
Compensation relating to stock options	826			826
Repurchase of common stock	(3,177)			(3,177)
Balance at Dec. 31, 2017	$ 1,306,606	$ (180,545)	$ (40,407)	$ 1,085,654

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	12 Months Ended
	Dec. 31, 2017
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	NOTE 1 — DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION: Spin-Off from Overseas Shipholding Group, Inc . On November 30, 2016 (the “Distribution Date”), International Seaways, Inc. (“INSW”), a Marshall Islands corporation, and its wholly owned subsidiaries (the “Company” or “INSW”, or “we” or “us” or “our”), became a public entity as a result of its spin-off (the “Distribution”) from Overseas Shipholding Group, Inc. (“OSG”), a publicly traded company incorporated in Delaware (United States). The spin-off separated OSG and INSW into two distinct businesses with separate management. OSG retained the U.S. Flag business and INSW holds entities and other assets and liabilities that formed OSG’s former International Flag business. On November 30, 2016, we amended and restated our articles of incorporation (“Amended and Restated Articles of Incorporation”). In accordance with the Amended and Restated Articles of Incorporation, immediately prior to the distribution, as described in the following paragraph, the Company effected a stock split of its 102.21 issued and outstanding shares of common stock, which were all owned by OSG, to allow for a prorata dividend of such shares to the holders of OSG common stock and warrants. In accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) ASC 260, Earnings Per Share , the Company adjusted the computations of basic and diluted earnings per share retroactively for all periods presented to reflect that change in its capital structure. Following the distribution our authorized capital stock consisted of 100,000,000 shares of common stock without par value and 10,000,000 shares of preferred stock without par value. The spin-off transaction was in the form of a pro rata dividend of 100% of the common stock of INSW to holders of OSG common stock and warrants. Effective as of 5:00 p.m., New York time, on the Distribution Date (the “Effective Time”), our common stock was distributed, on a pro rata basis, to OSG’s stockholders and warrant holders of record as of 5:00 p.m., New York time, on November 18, 2016 (the “Record Date”). On the Distribution Date, each holder of OSG common stock received 0.3333 shares of our common stock for every share of OSG common stock held on the Record Date. Each holder of OSG warrants received 0.3333 shares of our common stock for every one share of OSG common stock they would have received if they exercised their warrants immediately prior to the Distribution (or 0.063327 INSW shares per warrant), treating such warrants on an as-exercised basis without deduction for the exercise price of such warrants. Fractional shares of our common stock were not distributed in the spin-off. Holders of OSG common stock and warrants received cash in lieu of fractional shares of our common stock. Our common stock began “regular-way” trading on the New York Stock Exchange on December 1, 2016, under the symbol “INSW.” The spin-off was completed pursuant to a separation and distribution agreement (the “Separation and Distribution Agreement”) and several other agreements with OSG related to the spin-off, including a transition services agreement (the “Transition Services Agreement”) and an employee matters agreement (the “Employee Matters Agreement”) dated November 30, 2016. These agreements govern the relationship between us and OSG following the spin-off and provide for the allocation of various assets, liabilities, rights and obligations. These agreements also include arrangements for transition services that were provided by OSG to the Company and by the Company to OSG. See Note 13, “Related Parties,” for additional discussion of the significant agreements with OSG. Nature of the Business The Company is engaged primarily in the ocean transportation of crude oil and petroleum products in international market s . The Company’s business is currently organized into two rep ortable segments: Crud e Tankers and Product Carriers. The crude oil fleet is comprised of most major crude oil vessel classes. The products fleet transports refined petroleum product cargoes from refineries to consuming markets characterized by both long and short-haul routes. Through joint venture partnerships, the Company operates four liquefied natural gas (“LNG”) carriers and two Floating Storage and Offloading (“FSO”) service vessels. As of December 31, 201 7 , the Company’s operating fleet consisted of 55 vessels, 49 of which were owned (including four LNG carriers and two FSO service vessels in which the Company has joint venture ownershi p interests), with the remaining vessels chartered-in. Subsequent to December 31, 2017 , we delivered a 2002-built and a 2004-built MR to buyers ( see Note 5, “Vessels ”, to the accompanying consolidated financial statements ). Vessels chartered-in may be bareboat charters or time charters. Under either a bareboat charter or time charter, a customer pays a fixed daily or monthly rate for a fixed period of time for use of the vessel. Under a bareboat charter, the customer pays all costs of operating the vessel, including voyage expenses, such as fuel, canal tolls and port charges, and vessel expenses such as crew costs, vessel stores and supplies, lubricating oils, maintenance and repair, insurance and communications associated with operating the vessel. Under a time charter, the customer pays all voyage expenses and the shipowner pays all vessel expenses. The Company’s operating fleet list excludes vessels chartered-in where the duration of the charter was one year or less at inception. The Marshall Islands is the principal flag of registry of the Company’s vessels. Basis of Presentation The accompanying consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. For the eleven-month period ended November 30, 2016 and the y ears ended December 31, 2015 , the accompanying consolidated financial statements include the assets, liabilities, revenues and expenses of the individual entities that comprise the Company carved out from the historical results of operations, cost basis of the assets and liabilities and cash flows of OSG for these entities using both specific identification and allocation consistent with prior periods. For the eleven month period ended November 30, 2016 and the years ended December 31, 2015 , the Company functioned as part of the larger group of companies controlled by OSG, and accordingly, OSG performed certain corporate overhead functions for the Company. Therefore, certain costs related to the Company have been allocated from OSG. These allocated costs are primarily related to corporate administrative expenses, reorganization costs and employee related costs, including pensions and other benefits for corporate and shared employees, for the following functional groups: information technology, legal services, accounting and finance services, human resources, marketing and contract support, customer support, treasury and cash management, facility and other corporate and infrastructural services. The costs associated with these services and support functions have been allocated to the Company primarily based on either the proportion of time spent by employees within the above functions on tasks related to or for the benefit of the Company’s entities or the proportion of ship operating days of the Company. Ship operating days are defined as the total number of days vessels are owned or chartered in during a period. A portion of this cost allocation was offset by costs for certain corporate functions held within the Company (including information technology functions) that have historically provided services to OSG and non-INSW subsidiaries of OSG. The net costs allocated for these functions are included in general and administrative expenses, technical management and transition costs, separation and transition costs and reorganization items, net within the consolidated financial statements. The tax provisions for the Company have been provided using a separate tax return methodology. Management believes the assumptions and allocations are reasonable. The expenses and cost allocations have been determined on a basis considered to be a reasonable reflection of the utilization of services provided to or the benefit received by the Company during the periods relative to the total costs incurred by OSG. However, the amounts recorded may not be representative of the amounts that would have been incurred had the Company been an entity that operated independently of OSG. Consequently, these consolidated financial statements may not be indicative of the Company’s future performance and do not necessarily reflect what its consolidated results of operations, financial position and cash flows would have been had the Company operated as a separate entity apart from OSG during the eleven-month period ended November 30, 2016 and the year ended December 31, 2015. Following our spin-off from OSG on November 30, 2016, we now perform functions previously performed by OSG using internal resources and purchased services, some of which were being provided by OSG during a transitional period that ended on June 30, 2017 pursuant to the Transition Services Agreement. All intercompany balances and transactions within the Company have been eliminated. Investments in 50% or less owned affiliated companies, in which the Company exercises significant influence, are accounted for by the equity method. Dollar amounts, except per share amounts are in thousands.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2017
Significant Accounting Policies [Abstract]
Significant Accounting Policies	NOTE 2 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES: 1. Cash and cash equivalents — Interest-bearing deposits that are highly liquid investments and have a maturity of three months or less when purchased are includ ed in cash and cash equivalents. R estricted cash of $10,579 as of December 31, 201 7 represents legally restricted cash relating to the 2017 Debt Facilities (as defined in Note 8 , “Debt”). Such restricted cash reserves are included in the non-current assets section of the consolidated balance sheet. The 2017 Debt Facilities stipulate that net cash proceeds of any INSW asset sale or casualty event exceeding $5,000, are restricted and required to be reinvested in fixed or capital assets within twelve months of such sale or casualty event or used to repay the principal balance outstanding on the 2017 Debt Facilities. Activity relating to restricted cash is reflected in investing activities in the c onsolidated statements of cash flow.  2. Concentration of Credit Risk — Financial instruments that potentially subject the Company to concentrations of credit risk are voyage receivables due from charterers and pools in which the Company participates. With respect to voyage receivables, the Company limits its credit risk by performing ongoing credit evaluations. Voyage receivables reflected in the consolidated balance sheets as of December 31, 201 7 and 201 6 are net of an allowance for doubtful accounts of $108 and $70 , respectively. The provisions for doubtful accounts for t he years ended December 31, 2017, 2016 and 201 5 were not material. During the thr ee years ended December 31, 2017 , the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted for 89% and 90% of consolidated voyage receivables at December 31, 2017 and 2016 .  3. Inventories —Inventories, which consists principally of fuel, are stated at cost determined on a first-in, first-out basis.  4. Vessels, vessel lives, deferred drydocking expenditures and other property —Vessels are recorded at cost and are depreciated to their estimated salvage value on the straight-line basis over the lives of the vessels, which are generally 25 years. Each vessel’s salvage value is equal to the product of its lightweight tonnage and an estimated scrap rate of $300 per ton. Other property, including leasehold improvements, are recorded at cost and amortized on a straight-line basis over the shorter of the terms of the leases or the estimated useful lives of the assets, which range from three to seven years.  Interest costs are capitalized to vessels during the period that vessels are under construction, however, no inte rest was capitalized during 2017 , 201 6 or 201 5 . Expenditures incurred during a drydocking are deferred and amortized on the straight-line basis over the period until the next scheduled drydocking, generally two and a half to five years. The Company only includes in deferred drydocking costs those direct costs that are incurred as part of the drydocking to meet regulatory requirements, or are expenditures that add economic life to the vessel, increase the vessel’s earnings capacity or improve the vessel’s efficiency. Direct costs include shipyard costs as well as the costs of placing the vessel in the shipyard. Expenditures for normal maintenance and repairs, whether incurred as part of the drydocking or not, are expensed as incurred.  The carrying value of each of the Company’s vessels represents its original cost at the time it was delivered or purchased less depreciation calculated using estimated useful lives from the date such vessel was originally delivered from the shipyard. A vessel’s carrying value is reduced to its new cost basis (i.e., its current fair value) if a vessel impairment charge is recorded. 5. Impairment of long-lived assets —The carrying amounts of long-lived assets held and used by the Company are reviewed for potential impairment whenever events or changes in circumstances indicate that the carrying amount of a particular asset may not be fully recoverable. In such instances, an impairment charge would be recognized if the estimate of the undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than the asset’s carrying amount. This assessment is made at the individual vessel level since separately identifiable cash flow information for each vessel is available. The impairment charge, if any, would be measured as the amount by which the carrying amount of a vessel exceeded its fair value. If using an income approach in determining the fair value of a vessel, the Company will consider the discounted cash flows resulting from highest and best use of the vessel asset from a market-participant’s perspective. Alternatively, if using a market approach, the Company will obtain third party appraisals of the estimated fair value of the vessel. A long lived asset impairment charge results in a new cost basis being established for the relevant long lived asset. See Note 5 , “Vessels,” for further discussion on the impairment tests performed on certain of our vessels during the thr ee years ended December 31, 2017 .  6. Deferred finance charges —Finance charges, excluding original issue discounts, incurred in the arrangement and /or amendments resulting in the modification of debt are deferred and amortized to interest expense on either an effective interest method or straight-line basis over the life of the related debt. Unamortized deferred finance charges of $1,691 relating to the INSW Revolver Facility (as defined in Note 8 , “Debt”) are included in other assets in the consolidated balance sheets as of December 31, 2016. Unamortized deferred finance charges of $23,626 relating to the 2017 Term Loan Facility (as defined in Note 8 , “Debt”) and the 2017 Revolver Facility and $19, 827 relating to the INSW Term Loan are included in long-term debt on the consolidated balance sheets as of December 31, 2017 and 2016.  Interest expense relating to the amortization of deferred financing costs amounted to $5,115 in 201 7 , $ 6,449 in 201 6 and $5,625 in 201 5 .  7. Revenue and expense recognition —Revenues from time charters and bareboat charters are accounted for as operating leases and are thus recognized ratably over the rental periods of such charters, as service is performed. Voyage revenues and expenses are recognized ratably over the estimated length of each voyage, calculated on a discharge-to-discharge basis and, therefore, are allocated between reporting periods based on the relative transit time in each period. The impact of recognizing voyage expenses ratably over the length of each voyage is not materially different on a quarterly and annual basis from a method of recognizing such costs as incurred. The Company does not begin recognizing voyage revenue until a charter has been agreed to by both the Company and the customer, even if the vessel has discharged its cargo and is sailing to the anticipated load port on its next voyage. Under voyage charters, expenses such as fuel, port charges, canal tolls, cargo handling operations and brokerage commissions are paid by the Company whereas, under time and bareboat charters, such voyage costs are paid by the Company’s customers. For the Company’s vessels operating in pools, revenues and voyage expenses are pooled and allocated to each pool’s participants on a time charter equivalent (“TCE”) basis in accordance with an agreed-upon formula. Such TCE revenues are reported as pool revenues in the accompanying consolidated statement of operations. For the pools in which the Company participates, management monitors, among other things, the relative proportion of the Company’s vessels operating in each of the pools to the total number of vessels in each of the respective pools, and assesses whether or not the Company’s participation interest in each of the pools is sufficiently significant so as to determine that the Company has effective control of the pool. 8. Derivatives —ASC 815, Derivatives and Hedging , requires the Company to recognize all derivatives on the balance sheet at fair value. Derivatives that are not effective hedges must be adjusted to fair value through earnings. If the derivative is an effective hedge, depending on the nature of the hedge, a change in the fair value of the derivative is either recorded to current earnings (fair value hedge), or recognized in other comprehensive income/(loss) and reclassified into earnings in the same period or periods during which the hedge transaction affects earnings (cash flow hedge). The ineffective portion of an effective hedge and the full amount of the change in fair value of derivative instruments that do not qualify for hedge accounting are immediately recognized in earnings. The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as cash flow hedges to forecasted transactions. The Company also formally assesses (both at the hedge's inception and on an ongoing basis) whether the derivatives that are used in hedging transactions have been highly effective in offsetting changes in the cash flows of hedged items and whether those derivatives may be expected to remain highly effective in future periods. When it is determined that a derivative is not (or has ceased to be) highly effective as a hedge, the Company discontinues hedge accounting prospectively, as discussed below. The Company discontinues hedge accounting prospectively when (1) it determines that the derivative is no longer effective in offsetting changes in the cash flows of a hedged item such as forecasted transactions; (2) the derivative expires or is sold, terminated, or exercised; (3) it is no longer probable that the forecasted transaction will occur; or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate or desired. When the Company discontinues hedge accounting because it is no longer probable that the forecasted transaction will occur in the originally expected period, the gain or loss on the derivative remains in accumulated other comprehensive loss and is reclassified into earnings when the forecasted transaction affects earnings. However, if it is probable that a forecasted transaction will not occur by the end of the originally specified time period or within an additional two-month period of time thereafter, the gains and losses that were accumulated in other comprehensive loss will be recognized immediately in earnings. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company will carry the derivative at its fair value on the balance sheet, recognizing changes in the fair value in current-period earnings, unless it is designated in a new hedging relationship. During the three years ended December 31, 201 7 , no ineffectiveness gains or losses were recorded in earnings relative to interest rate caps entered into by the Company or its subsidiaries that qualified for hedge accounting. Any gain or loss realized upon the early termination of an interest rate cap is recognized as an adjustment of interest expense over the shorter of the remaining term of the cap or the hedged debt. See Note 9 , “Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures,” for additional disclosures on the Company’s interest rate caps and other financial instruments. 9. Income taxes — Substantially all of the companies included in the Company’s consolidated financial statements were excluded from the OSG consolidated group for U.S. income tax purposes for the eleven month period ended November 30, 2016 and the year ended December 31, 2015 . T he Company’s financial statements have been prepared on the basis that OSG was responsible for all U.S. taxes for periods prior to December 1, 2016. Prior to December 1, 2016, the Company had not operated as an independent stand-alone entity. However, for the purposes of these consolidated financial statements the Company has calculated income taxes as if it had filed relevant income tax returns on a stand-alone basis. T he Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Net deferred tax assets are recorded to the extent the Company believes these assets will more likely than not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. In the event the Company were to determine that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes in the period such determination is made. Uncertain tax positions are recorded in accordance with ASC 740, Income Taxes, on the basis of a two-step process whereby (1) the Company first determines whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the largest amount of tax benefit that is greater than 50% likely to be realized upon ultimate settlement with the related tax authority. 10. Valuation of equity method investments — When events and circumstances warrant, investments accounted for under the equity method of accounting are evaluated for impairment. An impairment charge is recorded whenever a decline in fair value of an investment below its carrying amount is determined to be other-than-temporary. Impairment charges related to equity method investments are record ed in equity in i ncome of a ffiliated c ompanies in the accompanying consolidated statements of operations. See Note 6 , “Equity Method Investments,” for further discussion of the Company’s evaluation of impairment of its equity method investments at December 31, 2017 and 2016, respectively.  11. Use of estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts of assets, liabilities, equity, revenues and expenses reported in the financial statements and accompanying notes. The most significant estimates relate to the depreciation of vessels and other property, amortization of drydocking costs, estimates used in assessing the recoverability of goodwill, equity method investments, intangible and other long-lived assets, liabilities incurred relating to pension benefits, and income taxes. Actual results could differ from those estimates.  12. Recently Adopted Accounting Standards — In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (ASC 815) , which makes more financial and nonfinancial hedging strategies eligible for hedge accounting, amends the presentation and disclosure requirements, and changes how companies assess effectiveness. It is intended to more closely align hedge accounting with companies’ risk management strategies, simplify the application of hedge accounting, and increase transparency as to the scope and results of hedging programs. The new guidance permits a qualitative effectiveness assessment for certain hedges instead of a quantitative test after initial qualification if the company can reasonably support an expectation of high effectiveness throughout the term of the hedge. An initial quantitative test to establish that the hedge relationship is highly effective is still required. For cash flow hedges, if the hedge is highly effective, all changes in the fair value of the derivative hedging instrument will be recorded in other comprehensive income. They will be reclassified to earnings when the hedged item impacts earnings. On the other hand, for fair value hedges, because the change in fair value of the hedged item and the derivative hedging instrument will still be recorded in current earnings, if the hedge is not 100% effective there will be an income statement impact. The standard will be effective for interim and annual periods beginning after December 31, 2018 and early adoption is permitted. Beginning December 1, 2017, the Company elected to early adopt this accounting standard with an initial application date of January 1, 2017. The adoption of this accounting standard had no impact on the Company’s consolidated financial statements since the hedge relationship that existed at the initial application date had expired prior to the adoption date . Also, the hedge relationship entered into after the December 1, 2017 adoption date had a forward start date of January 1, 2018.  In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting (ASC 718), which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, forfeitures, classification of awards as either equity or liabilities, and classification in the statement of cash flows. The standard is effective for annual periods beginning after December 31, 2016 and interim periods within that reporting period. As a result of the adoption of this accounting standard, effective January 1, 2017, the Company elected to account for forfeitures of share-based payments as they occur. The adoption of this accounting policy had no impact on the Company’s consolidated financial statements since management’s estimate of the forfeiture rate on share-based payment awards granted prior to January 1, 2017 was zero. In addition, the adoption of this accounting standard resulted in the presentation of $349 and $26 of cash paid to the tax authorities for shares withheld to satisfy the Company’s statutory income tax withholding obligations as a financing cash outflow in the consolidated statement of cash flows for the years ended December 31 , 2017 and 2016, respectively.  13. Recently Issued Accounting Standards — In September 2017, the FASB issued ASU 2017-13, Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments , which allows certain public business entities (“PBEs”) that otherwise would not meet the definition of a public business entity except for a requirement to include its financial statements or financial information in another entity’s filings with the SEC, to elect to use non-PBE transition dates for the sole purpose of adopting ASU No. 2016-02, Leases (ASC 842), and ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606). Accordingly, all financial statements or financial information of the Company’s FSO and LNG joint ventures that may be included in the Company’s filings with the SEC pursuant to SEC Regulation S-X Rule 4-08(g), Summarized Financial Information of Subsidiaries Not Consolidated and 50 Percent or Less Owned Persons, and/or SEC Regulation S-X Rule 3-09, Separate Financial Statements of Subsidiaries Not Consolidated and 50 Percent or Less Owned Persons, will likely not reflect the adoptions of ASC 606 and ASC 842 until January 1, 2019 and January 1, 2020, respectively.  In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (ASC 7 18), which provides guidance in regards to a change to the terms or conditions of a share-based payment award. An entity is required to account for the effects of a modification unless all the following are met: (1) the fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The guidance is to be applied prospectively to an award modified on or after the adoption date. Management does not expect the adoption of this accounting standard to have a material impact on the Company’s consolidated financial statements.  In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASC 715), which requires that an employer classify and report the service cost component in the same line item or items in the statement of operations as other compensation costs arising from services rendered by the pertinent employees during the period and disclose by line item in the statement of operations the amount of net benefit cost that is included in the statement of operations. The other components of net benefit cost would be presented in the statement of operations separately from the service cost component and outside the subtotal of income from operations. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The standard requires application using a retrospective transition method and allows a practical expedient that permits an employer to use the amounts disclosed in its pension and other postretirement benefit plan note for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements . Management does not expect the adoption of this accounting standard to have a material impact on the Company’s consolidated financial statements. Upon adoption, net benefit costs totaling $335 and $985 for the years ended December 31, 2017 and 2016, respectively, that is currently presented in the general and administrative expense line will be presented in the other (expense)/income line on the consolidated statement operations.  In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (ASC 230): Restricted Cash , which requires that amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The standard will be effective for annual periods beginning after December 31, 2017 and interim periods within that reporting period. T he adoption of this accounting standard will not have a material impact on the Company’s consolidated statements of cash flows.  In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (ASC 230), which amends the guidance in ASC 230 on the classification of certain cash receipts and payments in the statement of cash flows. The primary purpose of the ASU is to reduce the diversity in practice that has resulted from the lack of consistent principles on this topic with respect to (1) debt prepayment or debt extinguishment costs; (2) settlement of zero-coupon debt; (3) contingent consideration payments made after a business combination; (4) proceeds from the settlement of insurance claims; (5) proceeds from the settlement of corporate-owned life insurance policies; (6) distributions received from equity method investees; (7) beneficial interests in securitization transactions; and (8) separately identifiable cash flows and application of the predominance principle. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The guidance requires application using a retrospective transition method. We currently anticipate adopting the standard for classification of distributions received from equity method investees using the cumulative equity earnings approach, which will result in the retrospective reclassification of distributions received from certain affiliated companies accounted for by the equity method, from investing activities to operating activities. Management does not expect the adoption of the other provisions of this accounting standard to have a material impact on the Company’s consolidated financial statements.  In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842), which requires lessees to recognize most leases on the balance sheet. This is expected to increase both reported assets and liabilities. The standard will be effective for the first interim reporting period within annual periods beginning after December 15, 2018, although early adoption is permitted. Lessees and lessors will be required to apply the new standard at the beginning of the earliest period presented in the financial statements in which they first apply the new guidance, using a modified retrospective transition method. The requirements of this standard include a significant increase in required disclosures. Management is analyzing the impact of the adoption of this guidance on the Company’s consolidated financial statements, including assessing changes that might be necessary to information technology systems, processes and internal controls to capture new data and address changes in financial reporting. Management expects that the Company will recognize increases in reported amounts for property, plant and equipment and related lease liabilities upon adoption of the new standard.  In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606), a standard that will supersede virtually all of the existing revenue recognition guidance in U.S. GAAP. The standard establishes a five-step model that will apply to revenue earned from a contract with a customer. The standard’s requirements will also apply to the sale of some non-financial assets that are not part of an entity’s ordinary activities (e.g., sales of property or plant and equipment). Extensive disclosures will be required, including disaggregation of total revenue, information about performance obligations, changes in contract asset and liability account balances between periods and key judgments and estimates. The FASB has issued several amendments to the standard, including clarification of the accounting for licenses of intellectual property and identifying performance obligations. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the cumulative catch-up transition method). The new standard will be effective for us beginning January 1, 2018 and while not expected to have a material impact upon adoption, it could have a material impact on the Company’s consolidated financial statements going forward. We intend to adopt the standard using the cumulative catch-up transition method. We have undertaken a comprehensive approach to assessing the impact of the guidance on our business by reviewing our current accounting policies and practices to identify any potential differences that may result from applying the new requirements to our consolidated financial statements. In evaluating the impact of adopting this standard, we determined that (i) the timing and recognition of earnings from the pool arrangements and time charter/bareboat charter-out contracts to which the Company is party will not change significantly from current practice; (ii) there may be a change in the timing of revenue recognition under spot voyage contracts that may have a material impact on the Company’s consolidated financial statements, depending on the number of spot voyages we have in progress at a reporting period end and whether or not the underlying voyage charter has been determined to be a service only contract or a lease contract with a service component; (iii) there will be a significant expansion of required disclosures regarding revenue recognition, including a requirement to disclose the portion of total revenues recognized in accordance with other standards such as ASC 840, Leases ; and (iv) the use of time charter equivalent (“TCE”) revenues as a means of measuring performance and comparing results amongst shipping industry participants could become more challenging. In quantifying the cumulative catch up adjustment that will be recognized on January 1, 2018, we determined that as of December 31, 2017, only one of the Company’s vessels was operating on a spot voyage charter. A review of the terms of the charter agreement resulted in the determination that it was a short-term lease contract because the charterer had substantive decision-making rights with respect to the load and discharge ports. We concluded there would be no material cumulative catch up adjustment for this contract as the adoption of ASC 606 did not materially change the timing or the amount of the non-lease component of the revenue recognized ratably between contract signing date in November 2017 and discharge of cargo in January 2018 .

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	12 Months Ended
	Dec. 31, 2017
Earnings per Common Share [Abstract]
Earnings per Common Share	NOTE 3 — EARNINGS PER COMMON SHARE: Basic earnings per common share is computed by dividing earnings, after the deduction of dividends and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. The computation of diluted earnings per share assumes the issuance of common stock for all potentially dilutive stock options and restricted stock units not classified as participating securities. Participating securities are defined by ASC 260, Earnings Per Share, as unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents and are included in the computation of earnings per share pursuant to the two-class method.  There were 35,876 , 1,489 and 0 weight ed average shares of unvested restricted common stock shares considered to be participating securities for t he years ended December 31, 2017 , 201 6 and 201 5 , respectively. Such participating securities are allocated a portion of income , but not losses under the two-class method . Accordingly, no allocation was made to the participating securities under the two-class method for the year s ended December 31, 2017 and 2016. As of December 31, 2017, there were 105,429 shares of restricted stock units and 275,830 stock options outstanding considered to be potentially dilutive securities. The components of the calculation of basic and diluted earnings per share are as follows:       For the year ended December 31, 2017 2016 2015  Net (loss)/income $ (106,088) $ (18,223) $ 173,170   Weighted average common shares outstanding:  Basic 29,159,440 29,157,992 29,157,387  Diluted 29,159,440 29,157,992 29,157,387  Reconciliations of the numerator of the basic and diluted earnings per share computations are as follows:       For the year ended December 31, 2017 2016 2015  Net (loss)/income allocated to:  Common Stockholders $ (106,088) $ (18,223) $ 173,170  Participating securities - - -  $ (106,088) $ (18,223) $ 173,170  There were no dilutive equity awards ou tstanding for the years ended December 31, 2017, 2016 and 2015. Awards of 397,833 and 11,153 for the year ended 2017 and 2016, respectively, were not included in the computation of diluted earnings per share because inclusion of these awards would be anti-dilutive.

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING	12 Months Ended
	Dec. 31, 2017
Business and Segment Reporting [Abstract]
Business and Segment Reporting	NOTE 4 — BUSINESS AND SEGMENT REPORTING: The Company is engaged primarily in the ocean transportation of crude oil and petroleum products in the international market through the ownership and operation of a diversified fleet of vessels. The shipping industry has many distinct market segments based, in large part, on the size and design configuration of vessels required and, in some cases, on the flag of registry. Rates in each market segment are determined by a variety of factors affecting the supply and demand for vessels to move cargoes in the trades for which they are suited. Tankers are not bound to specific ports or schedules and therefore can respond to market opportunities by moving between trades and geographical areas. The Company charters its vessels to commercial shippers and foreign governments and governmental agencies primarily on voyage charters and on time charters.  The Company has two rep ortable segments: Crude Tankers and Product Carriers. The joint ventures with two floating storage and offloading service vessels are included in the Crude Tankers Segment. The joint venture with four LNG Carriers is included in Other. Adjusted income/(loss) from vessel operations for segment reporting is defined as income/(loss) from vessel operations before general and administrative expenses, third-party debt modification fees , separation and transition costs, technical management transition costs, and (loss) /gain on disposal of ve ssels and other property, including impairments . The accounting policies followed by the reportable segments are the same as those followed in the preparation of the Company’s consolidated financial statements.  Information about the Company’s reportable segments as of and for each of the years in the three-year period ended December 31, 2017 follows:        Crude Product  Tankers Carriers Other Totals  2017  Shipping revenues $ 192,426 $ 97,675 $ - $ 290,101  Time charter equivalent revenues 178,812 96,183 - 274,995  Depreciation and amortization 56,302 22,418 133 78,853  Loss on disposal of vessels and other property, including impairments 85,625 1,230 - 86,855  Adjusted income/(loss) from vessel operations 21,623 (8,385) (31) 13,207  Equity in income of affiliated companies 34,577 - 14,389 48,966  Investments in and advances to affiliated companies at December 31, 2017 260,884 15,612 102,398 378,894  Adjusted total assets at December 31, 2017 1,104,714 382,905 102,025 1,589,644  Expenditures for vessels and vessel improvements 172,164 1,371 - 173,535  Payments for drydockings 17,606 3,790 - 21,396  2016  Shipping revenues $ 271,764 $ 126,555 $ - $ 398,319  Time charter equivalent revenues 258,171 126,314 560 385,045  Depreciation and amortization 52,395 26,696 794 79,885  Loss on disposal of vessels and other property, including impairments 7,585 71,456 162 79,203  Adjusted income from vessel operations 111,768 13,327 710 125,805  Equity in income of affiliated companies 5,584 - 11,265 16,849  Investments in and advances to affiliated companies at December 31, 2016 266,470 15,296 76,915 358,681  Adjusted total assets at December 31, 2016 1,066,184 422,579 76,915 1,565,678  Expenditures for vessels and vessel improvements 691 1,297 - 1,988  Payments for drydockings 7,636 1,622 - 9,258  2015  Shipping revenues $ 324,703 $ 172,931 $ - $ 497,634  Time charter equivalent revenues 304,182 171,608 - 475,790  Depreciation and amortization 51,347 28,763 1,543 81,653  Loss/(gain) on disposal of vessels and other property 31 (3,231) (1,259) (4,459)  Adjusted income/(loss) from vessel operations 157,840 56,746 (1,176) 213,410  Equity in income of affiliated companies 34,371 - 11,188 45,559  Investments in and advances to affiliated companies at December 31, 2015 276,839 13,793 54,259 344,891  Adjusted total assets at December 31, 2015 1,148,361 505,353 43,340 1,697,054  Expenditures for vessels and vessel improvements 91 873 - 964  Payments for drydockings 13,842 6,886 - 20,728  Reconciliations of time charter equivalent revenues of the segments to shipping revenues as reported in the consolidated statements of operations follow:      For the year ended December 31, 2017 2016 2015  Time charter equivalent revenues $ 274,995 $ 385,045 $ 475,790  Add: Voyage expenses 15,106 13,274 21,844  Shipping revenues $ 290,101 $ 398,319 $ 497,634   Consistent with general practice in the shipping industry, the Company uses time charter equivalent revenues, which represents shipping revenues less voyage expenses, as a measure to compare revenue generated from a voyage charter to revenue generated from a time charter. Time charter equivalent revenues, a non-GAAP measure, provides additional meaningful information in conjunction with shipping revenues, the most directly comparable GAAP measure, because it assists Company management in making decisions regarding the deployment and use of its vessels and in evaluating their financial performance. Reconciliations of adjusted income from vessel operations of the segments to (loss)/income before income taxes, as reported in the consolidated statements of operations follow:      For the year ended December 31, 2017 2016 2015  Total adjusted income from vessel operations of all segments $ 13,207 $ 125,805 $ 213,410  General and administrative expenses (24,736) (31,618) (41,516)  Third-party debt modification fees (9,240) - -  Separation and transition costs (604) (9,043) -  Technical management transition costs - - (39)  (Loss)/gain on disposal of vessels and other property,  including impairments (86,855) (79,203) 4,459  Consolidated (loss)/income from vessel operations (108,228) 5,941 176,314  Equity in income of affiliated companies 48,966 16,849 45,559  Other (expense)/income (6,344) (966) 66  Interest expense (40,438) (39,476) (42,970)  Reorganization items, net - (131) (5,659)  (Loss)/income before income taxes $ (106,044) $ (17,783) $ 173,310  Reconciliations of total assets of the segments to amounts included in the consolidated balance sheets follow:     At December 31, 2017 2016  Total adjusted assets of all segments $ 1,589,644 $ 1,565,678  Corporate unrestricted cash and cash equivalents 60,027 92,001  Corporate restricted cash 10,579 -  Other unallocated amounts 4,234 4,842  Consolidated total assets $ 1,664,484 $ 1,662,521   Certain additional information about the Company’s operations for each of the years in the three year period ended December 31, 2017 follows:      Crude Product  Tankers Carriers Other Consolidated  2017  Total vessels, deferred drydock and other property at December 31, 2017 $ 800,362 $ 339,627 $ 374 $ 1,140,363  2016  Total vessels, deferred drydock and other property at December 31, 2016 $ 753,028 $ 377,095 $ 484 $ 1,130,607  2015  Total vessels, deferred drydock and other property at December 31, 2015 $ 804,514 $ 472,675 $ 297 $ 1,277,486

VESSELS, DEFERRED DRYDOCK AND O

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY	12 Months Ended
	Dec. 31, 2017
Vessels, Deferred Drydock and Other Property [Abstract]
Vessels, Deferred Drydock and Other Property	NOTE 5 — VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY: Vessels and other property , excluding vessel held for sale, consist of the following:     As of 2017 2016  Vessels, at cost $ 1,404,360 $ 1,478,940  Accumulated depreciation (302,087) (381,449)  Vessels, net 1,102,273 1,097,491   Other property, at cost 7,377 8,680  Accumulated depreciation and amortization (4,923) (6,121)  Other property, net 2,454 2,559   Total Vessels and other property $ 1,104,727 $ 1,100,050  All except one of the Company’s vessels are pledged as collateral under the INSW Facilities (see Note 8, “Debt”). The aggregate carrying value of the 42 vessels pledged as collateral under the INSW Facilities at December 31, 2017, including a 2002-built MR which was held for sale as of December 31, 2017, was $1,102,844 . A breakdown of the carrying value of the Company’s vessels by reportable segment and fleet as of December 31, 2017 and 2016 follows:      As of December 31, 2017  Net Average Number of  Accumulated Carrying Vessel Age Owned  Cost Depreciation Value (by dwt) Vessels   Crude Tankers  VLCC (includes ULCC) $ 663,880 $ (209,966) $ 453,914 12.5 10  Suezmax 117,259 (1,821) 115,438 0.4 2  Aframax 167,146 (21,064) 146,082 12.6 7  Panamax 61,120 (538) 60,582 15.3 8  Total Crude Tankers 1,009,405 (233,389) 776,016 (1) 12.1 27   Product Carriers  LR2 73,681 (9,305) 64,376 3.4 1  LR1 106,176 (13,122) 93,054 9.0 4  MR 215,098 (46,271) 168,827 11.5 10  Total Product Carriers 394,955 (68,698) 326,257 (2) 9.6 15   Fleet Total $ 1,404,360 $ (302,087) $ 1,102,273 11.7 42  (1) Includes seven VLCCs, two Suezmaxes, and three Aframaxes with an aggregate carrying value of $581,461 , which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $459,000 by $122,461 . (2) Includes one LR2, four LR1s and four MRs with an aggregate carrying value of $281,383 , which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $209,375 , by $72,008 .      As of December 31, 2016  Net Average Number of  Accumulated Carrying Vessel Age Owned  Cost Depreciation Value (by dwt) Vessels   Crude Tankers  VLCC (includes ULCC) $ 681,891 $ (235,159) $ 446,732 12.1 9  Aframax 247,863 (66,943) 180,920 11.6 7  Panamax 121,810 (18,506) 103,304 14.3 8  Total Crude Tankers 1,051,564 (320,608) 730,956 12.3 24   Product Carriers  LR2 73,681 (6,601) 67,080 2.4 1  LR1 106,176 (8,474) 97,702 8.1 4  MR 247,519 (45,766) 201,753 11.2 13  Total Product Carriers 427,376 (60,841) 366,535 9.3 18   Fleet Total $ 1,478,940 $ (381,449) $ 1,097,491 11.7 42  Vessel activity for the three years ended December 31, 2017 is summarized as follows:      Accumulated Net Book  Vessel Cost Depreciation Value  Balance at January 1, 2015 $ 1,648,115 (341,575) $ 1,306,540  Purchases and vessel additions 1,531 -  Disposals (6,755) 1,003  Depreciation - (64,385)  Balance at December 31, 2015 1,642,891 (404,957) 1,237,934  Purchases and vessel additions 2,127 -  Disposals - (63,328)  Depreciation (166,078) 86,836  Balance at December 31, 2016 1,478,940 (381,449) 1,097,491  Purchases and vessel additions 174,108 -  Disposals and transfer to held for sale (23,266) 2,232  Depreciation - (59,883)  Impairment (225,422) 137,013  Balance at December 31, 2017 $ 1,404,360 $ (302,087) $ 1,102,273  The total of purchases and vessel additions will differ from expenditures for vessels as shown in the consolidated statements of cash flows because of the timing of when payments were made. Vessel Impairments The Company gave consideration as to whether events or changes in circumstances had occurred since December 31, 2016 that could indicate that the carrying amounts of the vessels in the Company’s fleet may not be recoverable as of Dec ember 3 1 , 2017. Factors considered included declines in valuations during 2017 for vessels of certain sizes and ages, any negative changes in forecasted near term charter rates, and an increase in the likelihood that the Company will sell certain of its vessels before the end of their estimated useful lives in conjunction with the Company’s fleet renewal program. The Company concluded that the above indicators constituted impairment trigger events for eighteen vessels (one ULCC, one VLCC, six Aframaxes, eight Panamaxes and two LR1s) as of Dec ember 3 1 , 201 7 and three vessels (one Panamax and two MRs) as of Sept ember 3 0 , 2017.  In developing estimates of undiscounted future cash flows for performing Step 1 of the impairment tests, the Company utilized weighted probabilities assigned to possible outcomes for the vessels that the Company was considering to sell or recycle before the end of their respective useful lives in conjunction with the Company’s fleet renewal program. T he Company made assumptions about future performance, with significant assumptions being related to charter rates, ship operating expenses, utilization, drydocking requirements, residual value and the estimated remaining useful lives of the vessels. These assumptions are based on historical trends as well as future expectations. The estimated daily time charter equivalent rates used for unfixed days were based on a combination of (i) internally forecasted rates that are consistent with forecasts provided to the Company’s senior management and Board of Directors, and (ii) the trailing 12-year historical average rates, based on monthly average rates published by a third party maritime research service. The internally forecasted rates were based on management’s evaluation of current economic data and trends in the shipping and oil and gas industries. Management used the published 12-year historical average rates in its assumptions because it is management’s belief that the 12-year period captures an even distribution of strong and weak charter rate periods, which results in the use of an average mid-cycle rate that is in line with management’s forecast of a return to mid-cycle charter rate levels in the medium term. Recognizing that the transportation of crude oil and petroleum products is cyclical and subject to significant volatility based on factors beyond the Company’s control, management believes the use of estimates based on the combination of internally forecasted rates and 12-year historical average rates calculated as of the reporting date to be reasonable.  Estimated outflows for operating expenses and drydocking requirements are based on historical and budgeted costs and are adjusted for assumed inflation. Utilization is based on historical levels achieved, and estimates of a residual value for recyclings are based upon published 12-year historical data or the pattern of scrap rates used in management’s evaluation of salvage value for purposes of recording depreciation.  In estimating the fair value of the vessels for the purposes of Step 2 of the impairment tests, the Company considered the market and income approaches by using a combination of third party appraisals, current recycling market data, and discounted cash flow models prepared by the Company. In preparing the discounted cash flow models, the Company used a methodology consistent with that described above, and discounted the cash flows using its current estimate of INSW’s weighted average cost of capital. Based on the tests performed, impairment charges totaling $81,062 and $7,346 were recorded on twelve vessels (one ULCC, one VLCC, four Aframaxes and six Panamaxes) at December 31, 2017 and three vessels (one Panamax and two MRs) as of September 30, 2017, respectively to write-down their carrying values to their estimated fair values.  The Company monitored the industry wide decline in vessel valuations during 2016 and specifically from June 30, 2016 to September 30, 2016, and September 30, 2016 to December 31, 2016, as well as the decline in forecasted near term charter rates, and concluded that the declines in vessel valuations and in forecasted near term charter rates constituted impairment trigger events for 28 vessels as of September 30, 2016 and 24 vessels as of December 31, 2016. In developing estimates of undiscounted future cash flows for performing Step 1 of the impairment tests, the Company utilized the methodology described above.  In estimating the fair value of the vessels for the purposes of Step 2 of the September 30, 2016 impairment tests, the Company developed fair value estimates that utilized a market approach which considered an average of two vessel appraisals. Based on the tests performed, impairment charges totaling $49,640 were recorded on two LR1s, an Aframax and a Panamax to write-down their carrying values to their estimated fair values at September 30, 2016. In estimating the fair values of the vessels for the purposes of Step 2 of the December 31, 2016 impairment tests, the Company considered the market and income approaches by using a combination of third party appraisals and discounted cash flow models prepared by the Company. In preparing the discounted cash flow models, the Company used a methodology consistent with that described above, and discounted the cash flows using its current estimate of INSW’s weighted average cost of capital. Based on the tests performed, impairment charges aggregating $29,602 were recorded on one Panamax and seven MRs to write-down their carrying values to their estimated fair values at December 31, 2016.  During its evaluations as to whether or not events or circumstances existing during 2015 resulted in a triggering event for impairment testing of its fleet, Management gave consideration to average TCE rates earned by its vessels versus INSW’s 2015 budget, near term rate forecasts, significant changes in third party valuation appraisals of vessels, and plans or intentions that materially affect how the international fleet w ould be used in the next 12 months (including disposals). Management concluded there was no triggering event for impairment testing.  Management also gave consideration as to whether events or changes in circumstances had occurred since December 2014 that could indicate that the carrying amounts of the vessels in its fleet may not be recoverable as of December 31, 2015. INSW concluded that no such events or changes in circumstances had occurred to warrant a change in the assumptions utilized in the December 2014 impairment tests of its fleet.  Vessel Acquisitions and Deliveries  During 2017, the Company acquired two 2017-built Suezmax tankers for an aggregate price of $116,000 , which were delivered in July 2017, and one 2010-built VLCC tanker for a price of $53,000 , which was delivered in November 2017.  In Decem ber 2017, the Company entered into a binding Letter of Intent (“LOI”) for the acquisition of six VLCC tankers including one 2015-built and five 2016-built for a price of $434 ,000 . The transaction is expected to close in the second quarter of 2018. The Company’s obligation to consummate the transaction is subject to a number of conditions. Either party is permitted to terminate the LOI on or after March 31, 2018 if the parties have not entered into a definitive stock purchase agreement by such date and the party terminating the LOI is not otherwise in breach thereof.  Vessel Sales  During 2017, the Company recognized an aggregate gain on disposal of vessels of $1,594 relating to the sale of a 2001-built MR and a 2004-built MR. During the last quarter of 2017, the Company entered into memorandums of agreement for the sale of a 2002-built MR and a 2004-built MR, which were delivered to buyers during the first quarter of 2018. The 2002-built MR had been classified as vessel held for sale as of December 31, 2017. The Company recognized gains on such sales in 2018.  There were no vessels sold during the year ended December 31, 2016. During the year ended December 31, 2015, the Company sold a 1998-built MR and recognized a gain on sale of $3,236 . Drydocking activity for the three years ended December 31, 2017 is summarized as follows:     2017 2016 2015  Balance at January 1 $ 30,557 $ 37,075 $ 29,325  Additions 19,205 8,822 22,981  Sub-total 49,762 45,897 52,306  Drydock amortization (18,367) (15,340) (15,231)  Amount charged to loss/gain on sale of vessels (867) - -  Balance at December 31 $ 30,528 $ 30,557 $ 37,075 

EQUITY METHOD INVESTMENTS

EQUITY METHOD INVESTMENTS	12 Months Ended
	Dec. 31, 2017
Equity Method Investments [Abstract]
Equity Method Investments	NOTE 6 — EQUITY METHOD INVESTMENTS: Investments in affiliated companies include joint ventures accounted for using the equity method. As of December 31, 2017, the Company had an approximate 50% interest in three joint ventures. One joint venture operates four LNG carriers (the “LNG Joint Venture”). The other two joint ventures converted two ULCCs to Floating Storage and Offloading Service vessels (collectively the “FSO Joint Venture”). FSO Joint Venture In May 2017 , the FSO Joint Venture signed two five-year service contracts with North Oil Company (“NOC”), the new operator of the Al Shaheen oil field, off the coast of Qatar, relating to the two FSO service vessels. The shareholders of NOC are Qatar Petroleum Oil & Gas Limited and Total E&P Golfe Limited. Such contracts commenced at the expiry of the existing contracts with Maersk Oil Qatar AS during the third quarter of 2017 . The Company has a 50% interest in this joint venture . The FSO Joint Venture financed the purchase of the vessels from each of Euronav NV and INSW and their conversion costs through partner loans and a long-term bank financing, which was secured by, among other things, the service contracts and the FSOs themselves. Approximately $75,343 was outstanding under the bank financing facility as of December 31, 2016. In July 2017, the FSO Joint Venture repaid the principal balance outstanding on the bank financing facility, using cash on hand. The FSO Joint Venture previously entered into floating-to-fixed interest rate swaps with major financial institutions. These agreements, which paid fixed rates of approximately 3.9% and received floating rates based on LIBOR, had maturity dates ranging from July to September 2017. In conjunction with the repayment of the principal balance outstanding on the bank financing facility, the interest rate swap associated with the FSO Africa was terminated early and settled on June 15, 2017. The interest rate swap associated with the FSO Asia was settled upon maturity in July 2017. As of December 31, 201 6, the joint venture had a liability of $2,236, for the fair value of the swaps associated with the FSO Africa and FSO Asia. The Company’s share of the effective portion of such amount, aggregating $111 at December 31, 2016, is included in accumulated other comprehensive loss in the accompanying balance sheet.  The FSO Joint Venture is party to a number of contracts to which INSW serves as guarantor. See Note 12, “Related Parties,” for additional information relating to guarantees.  LNG Joint Venture In November 2004, the Company formed a joint venture with Qatar Gas Transport Company Limited (Nakilat) (“QGTC”) whereby companies in which OSG holds a 49.9% interest ordered four 216,200 cbm LNG Carriers. Upon delivery in late 2007 and early 2008, these vessels commenced 25 -year time charters to Qatar Liquefied Gas Company Limited (2) (‘‘LNG Charterer’’). QGTC subsequently contributed its ownership interests in the joint venture to its wholly owned subsidiary, Nakilat Marine Services Ltd. The aggregate construction cost for such newbuildings was financed by the joint venture through long-term bank financing that is nonrecourse to the partners and partner contributions. Approximately $ 597,129 and $638,827 was outstanding under this secured facility as of December 31, 2017 and 2016, respectively. The joint venture has entered into floating-to-fixed interest rate swaps with a group of major financial institutions pursuant to which it pays fixed rates of approximately 4.9% and receives a floating rate based on LIBOR. The interest rate swap agreements have maturity dates ranging from July to November 2022 and cover notional amounts aggregating $576,429 and $617,636 at December 31, 2017 and 2016, respectively. These swaps are being accounted for as cash flow hedges. As of December 31, 2017 and 2016, the joint venture recorded a liability of $58,243 and $80,458 , respectively, for the fair value of these swaps. The Company’s share of the effective portion of the fair value of these swaps, $ 28,980 and $40,076 at December 31, 2017 and 2016, respectively, is included in accumulated other comprehensive loss in the accompanying consolidated balance sheets.  Impairment of Equity Method Investments  Management gave consideration as to whether events or changes in circumstances had occurred since December 2016 that could indicate that the carrying amounts of its investments in the FSO Joint Venture and LNG Joint Venture may not be recoverable as of December 31, 2017. Management concluded that no such events or changes in circumstances had occurred to warrant an impairment testing .  In December 2016, evidence of an other-than-temporary decline in the fair value of the Company’s investments in its FSO Joint Venture below its carrying value was identified by the Company. Specifically, management concluded that the lower charter rate expected over the duration of the recently awarded five-year service contracts commencing in the third quarter of 2017 was negative evidence indicating that the excess of the carrying value of the Company’s investment in these joint ventures over their fair value was other-than-temporary as of December 31, 2016. As the Company determined that other-than-temporary impairments existed in relation to its investments in the FSO Joint Venture, impairment charges aggregating $30,475 were recorded to write down the investments to their estimated fair values as of December 31, 2016. In estimating the fair value of the Company’s investments in the FSO Joint Ventures as of December 31, 2016, the Company utilized an income approach by preparing discounted cash flow models since there is a lack of comparable market transactions for the specially built assets held by the FSO Joint Venture. In preparing the discounted cash flow models, the Company used a methodology largely consistent with the methodology and assumptions detailed in Note 6, “Vessels, Deferred Drydock and Other Property” above with the exception being that as the assets owned by the joint ventures serve under specific service contracts, the estimated charter rates for periods after the expiry of the existing contracts are based upon management’s internally forecasted rates. The cash flows were discounted using the current estimated weighted average cost of capital for each joint venture, which approximated 9.5% and took into consideration country risk, entity size and uncertainty with respect to the cash flows for periods beyond the current charter expiries.  Financial Information of Significant Equity Method Investments  Investments in and advances to affiliated companies as reflected in the accompanying consolidated balance sheet as of December 31, 2017 consisted of: FSO Joint Venture of $251,594 , LNG Joint Venture of $102,398 and Other of $24,902 (which primarily relates to working capital deposits that the Company maintains for commercial pools in which it participates).  Financial information for the equity method investees that were significant for the three years ended December 31, 2017, adjusted for basis and accounting policy differences, is as follows:       For the year ended December 31, 2017 2016 2015  Shipping revenues $ 234,916 $ 247,451 $ 245,444  Ship operating expenses (106,228) (114,487) (113,639)  Income from vessel operations 128,688 132,964 131,805  Other income 3,497 830 2,357  Interest expense (36,831) (43,038) (47,218)  Income tax provision (1,886) - -  Net income $ 93,468 $ 90,756 $ 86,944   Percentage of ownership in equity investees 49.9% - 50.0 % 49.9% - 50.0% 49.9% - 50.0%  Equity in income/(loss) of affiliated companies, before  consolidating and reconciling adjustments $ 46,704 $ 45,355 $ 43,449   Impairment of equity method investments in FSO Joint Venture - (30,475) -  Amortization on deferred gain on 2009 sale  of TI Africa to FSO Joint Venture 2,301 2,409 2,409  Amortization of interest capitalized during construction of  LNG vessels (419) (419) (419)  Other 380 (21) 120  Equity in income/(loss) of affiliated companies $ 48,966 $ 16,849 $ 45,559  The tables below present the financial position for the equity method investees that were significant and a reconciliation of the Company’ s share of the joint ventures’ total equity to the investments in and advances to affiliates line on the consolidated balance sheet s as of December 31, 2017 and 2016:      As of December 31, 2017 2016  Current assets $ 77,545 $ 128,531  Vessels, net 1,344,613 1,386,836  Other assets 65,551 66,708  Total assets $ 1,487,709 $ 1,582,075   Current liabilities $ 78,273 $ 150,153  Long-term debt and other non-current liabilities 917,564 1,055,922  Equity 491,872 376,000  Total liabilities and equity $ 1,487,709 $ 1,582,075   Percentage of ownership in equity investees 49.9% - 50.0% 49.9% - 50.0%  INSW Share of affiliate's equity, before consolidating and reconciling adjustments $ 245,751 $ 187,868   Impairment of equity method investments in FSO Joint Venture (30,475) (30,475)  Advances from shareholders of FSO Joint Venture (2) 162,762 203,513  Unamortized deferred gain on 2009 sale of TI Africa to FSO Joint Venture, net (34,284) (36,585)  Unamortized interest capitalized during construction of LNG vessels 10,275 10,693  Other (1) 24,865 23,667  Investments in and advances to affiliated companies $ 378,894 $ 358,681  (1) Primarily relates to working capital deposits that the Company maintains with the commercial pools in which it participates. (2) Such advances are unsecured, interest free and not repayable within one year . See Note 9, “Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures,” and Note 14, “Accumulated Other Comprehensive Loss,” for additional disclosures relating to the FSO and LNG joint venture interest rate swap agreements.

VARIABLE INTEREST ENTITIES ("VI

VARIABLE INTEREST ENTITIES ("VIEs")	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities ("VIEs") [Abstract]
Variable Interest Entities ("VIEs")	NOTE 7 —VARIABLE INTEREST ENTITIES (“VIEs”): At December 31, 2017 , the Company participates in s even commercial pools and three joint ventures. Commercial pools operate a large number of vessels as an integrated transportation system, which offers customers greater flexibility and a higher level of service while achieving scheduling efficiencies. Participants in the commercial pools contribute one or more vessels and generally provide an initial contribution towards the working capital of the pool at the time they enter their vessels. The pools finance their operations primarily through the earnings that they generate. INSW enters into joint ventures to take advantage of commercial opportunities. INSW entities have entered into joint ventures wit h different partners (see Note 6 , “Equity Method Investments”). In each joint venture, the INSW entities have the same relative rights and obligations and financial risks and rewards as i ts partners. INSW evaluated all ten arrangements to determine if they were variable interest entities (“VIEs”). INSW determined that one of the pools and two of the joint ventures met the criteria of a VIE and, therefore, INSW reviewed its participation in these VIEs to determine if it was the primary beneficiary of any of them.  INSW reviewed the legal documents that govern the creation and management of the VIEs described above and also analyzed its involvement to determine if INSW was a primary beneficiary in any of these VIEs. A VIE for which INSW is determined to be the primary beneficiary is required to be consolidated in its financial statements.  The formation agreements for the commercial pool state that the board of the pool has decision making power over their significant decisions. In addition, all such decisions must be approved unanimously by the board. Since INSW shares power to make all significant economic decisions that affect the pool and does not control a majority of the board, INSW is not considered a primary beneficiary of the pool.  The FSO joint venture s described in Note 6 , “Equity Method Investments,” w ere determined to be VIE s . The formation agreements of the joint venture s state that all significant decisions must be approved by the majority of the board. As a result, INSW shares power to make all significant economic decisions that affect this joint venture and does not control a majority of the board and is not considered a primary beneficiary. Accordingly, INSW accounts for th ese investment s under the equity method of accounting.  The joint ventures ’ formation agreements require INSW and its joint venture partner to provide financial support as needed. INSW has provided and will continue to provide suc h support as described in Note 6 , “Equity Method Investments.”  The following table presents the carrying amounts of assets and liabilities in the consolidated balance sheets related to the VIEs described above as of December 31, 2017 and 2016:      Consolidated Balance Sheet as of December 31, 2017 2016  Investments in Affiliated Companies $ 255,456 $ 261,403 In accordance with accounting guidance, the Company evaluated its maximum exposure to loss related to these VIEs by assuming a complete loss of the Company’s investment in these VIEs . The table below compares the Company’s liability in the consolidated balance sheet to the maximum exposure to loss at December 31, 2017:         Consolidated Balance Sheet Maximum Exposure to Loss  Other Liabilities $ - $ 255,456  In addition, as of December 31, 201 7 , the Company had approximately $12,617 of trade receivables from pools that were determined to be VIEs. These trade receivables, which are included in voyage receivables in the accompanying consolidated balance sheet, have been excluded from the above tables and the calculation of INSW’s maximum exposure to loss. The Company does not record the maximum exposure to loss as a liability because it does not believe that such a loss is probable of occurring as of December 31, 201 7 .

DEBT

DEBT	12 Months Ended
	Dec. 31, 2017
Debt [Abstract]
Debt	NOTE 8 —DEBT:  Debt consists of the following:     December 31, December 31,  2017 2016  2017 Term Loan Facility, due 2022, net of unamortized discount  and deferred costs of $23,074 $ 523,489 $ -  2017 Revolver Facility, net of unamortized deferred costs of $552 29,448 -  INSW Term Loan Facility, due 2019, net of unamortized discount  and deferred costs of $20,311 - 439,651  552,937 439,651  Less current portion (24,063) (6,183)  Long-term portion $ 528,874 $ 433,468   Capitalized terms used hereafter have the meaning given in these consolidated financial statements or in the respective transaction documents referred to below, including subsequent amendments thereto. 2017 Debt Facilities On June 22, 2017, INSW, its wholly owned subsidiary, International Seaways Operating Corporation (the “Administrative Borrower” or “ISOC”) and certain of its subsidiaries entered into secured debt facilities with Jefferies Finance LLC and JP Morgan Chase Bank, N.A., as joint lead arrangers, UBS Securities LLC, as joint bookrunner, DNB Markets Inc., Fearnley Securities AS, Pareto Securities Inc. and Skandinaviska Enskilda Banken AB (Publ) as co-managers, and the other lenders party thereto, consisting of (i) a revolving credit facility of $50,000 (the “2017 Revolver Facility”) and (ii) a term loan of $500,000 (the “2017 Term Loan Facility” and together with the 2017 Revolver Facility, the “2017 Debt Facilities”) containing an accordion feature whereby the 2017 Term Loan Facility could be increased up to an additional $50,000 subject to certain conditions. The 2017 Term Loan Facility matures on June 22, 2022, and the 2017 Revolver Facility matures on December 22, 2021. The maturity dates for the 2017 Debt Facilities are subject to acceleration upon the occurrence of certain events (as described in the credit agreement).  The 2017 Debt Facilities are secured by a first lien on substantially all of the assets of the Administrative Borrower and certain of its subsidiaries. On June 22, 2017, the proceeds received from the 2017 Term Loan Facility were used to repay the $458,416 outstanding balance under the INSW Facilities (defined below) and to pay certain expenses related to the refinancing. The remaining proceeds will be used for general corporate purposes, including fleet renewal and growth.  On July 19, 2017, the Company drew down $50,000 under the 2017 Revolver Facility, and on July 24, 2017, the Company entered into an amendment of the 2017 Debt Facilities (the “First Amendment”) to effect the increase of the 2017 Term Loan Facility by $50,000 , pursuant to the accordion feature described above. Except as related to such increase, no other terms of the 2017 Debt Facilities were amended. The net proceeds f rom these two borrowings were used for general corporate purposes, including funding the acquisition of two 2017-built Suezmax tankers as described above in Note 5, “Vessels.” On August 18, 2017, the outstanding balance under the 2017 Revolver Facility was repaid in full using cash on hand and proceeds of the sale of the 2001-built MR described in Note 5, “Vessels,” above.  On November 6, 2017, the Company drew down $30,000 under the 2017 Revolver Facility in order to partially fund the acquisition of a 2010-built VLCC tanker as described above in Note 5, “Vessels.”  Interest on the 2017 Debt Facilities is calculated, at the Administrative Borrower’s option, based upon (i) an alternate base rate (“ABR”) plus the applicable margin or (ii) Adjusted LIBOR plus the applicable margin. ABR is defined as the highest of (i) the Base Rate ( i.e. , the prime rate published in The Wall Street Journal ), (ii) the Federal Funds Effective Rate plus 0.50% , (iii ) the one-month Adjusted LIBOR Rate plus 1.00% and (iv) 2.00% per annum. The applicable margins and floor interest rates for each facility are as follows:     Facility 2017 Term Loan Facility 2017 Revolver Facility  Rate ABR LIBOR ABR LIBOR  Floor 2.00% 1.00% 2.00% 1.00%  Applicable Margin 4.50% 5.50% 2.50% 3.50%  The 2017 Term Loan Facility amortizes in quarterly installments equal to 0.625% of the original principal amount of the loan for the first four quarterly installments and equal to 1.25% of the original principal amount of the loan for all quarterly installments thereafter. The 2017 Term Loan Facility is subject to additional mandatory annual prepayments in an aggregate principal amount of 50% of Excess Cash Flow, as defined in the credit agreement.  Management determined that it had no Excess Cash Flow under the 201 7 Term Loan Facility for the nine months ended Dec ember 3 1 , 2017. Accordingly, there is currently no mandatory prepayment expected during the first quarter of 2018.  As set forth in the 2017 Debt Facilities credit agreement, the 2017 Debt Facilities contain certain restrictions relating to new borrowings and INSW’s ability to receive cash dividends, loans or advances from ISOC and its subsidiaries that are Restricted Subsidiaries. As of December 31 , 2017, permitted cash dividends that can be distributed to INSW by ISOC under the 2017 Term Loan Facility was $15,000 .  The 2017 Debt Facilities have covenants to maintain the aggregate Fair Market Value (as defined in the credit agreement) of the Collateral Vessels at greater than or equal to $300,000 at the end of each fiscal quarter and to ensure that at any time, the outstanding principal amounts of the 2017 Debt Facilities and certain other secured indebtedness permitted under credit agreement minus the amount of unrestricted cash and cash equivalents does not exceed 65% of the aggregate Fair Market Value of the Collateral Vessels plus the Fair Market Value of certain joint venture equity interests. The Company had substantial headroom under this covenant as of December 31, 2017, with an estimated ratio of 41% .  As of December 31, 201 7 , the aggregate annual principal payments required to be made on the 2017 Term Loan Facility are as follows:       Year Amount  2018 $ 24,063  2019 27,500  2020 27,500  2021 27,500  2022 440,000  Aggregate principal payments required $ 546,563   INSW Facilities On June 22, 2017, the agreements governing the INSW Facilities — a secured term loan facility in the aggregate amount of $628,375 (the “INSW Term Loan”) and a secured revolving loan facility of up to $50,000 (the “INSW Revolver Facility”), dated as of August 5, 2014, as amended by that certain First Amendment, dated as of June 3, 2015, that certain Second Amendment, dated as of July 18, 2016, that certain Third Amendment, dated as of September 20, 2016 and that certain Fourth Amendment, dated as of November 30, 2016, among INSW, OIN Delaware LLC (the sole member of which is INSW), certain INSW subsidiaries, Jefferies Finance LLC, as administrative agent, and other lenders party thereto, were terminated in accordance with their terms.  Interest Expense  The following table summarizes interest expense, including amortization of issuance and deferred financing costs (for additional information related to deferred financing costs see Note 2, “Significant Accounting Policies”), commitment, administrative and other fees, recognized during the years ended December 31, 2017, 2016 and 2015 with respect to the Company’s debt facilities:      Debt facility 2017 2016 2015  2017 Term Loan Facility, due 2022 $ 22,546 $ - $ -  2017 Revolver Facility, due 2021 495 - -  INSW Facilities, due 2019 16,743 38,442 42,688  Total debt related interest expense $ 39,784 $ 38,442 $ 42,688    The following table summarizes interest paid, excluding deferred financing fees paid, and capitalized interest, during the years ended December 31, 2017, 2016 and 2015 with respect to the Company’s debt facilities:      Debt facility 2017 2016 2015  2017 Term Loan Facility, due 2022 $ 16,319 $ - $ -  2017 Revolver Facility, due 2021 316 - -  INSW Facilities, due 2019 16,732 33,039 36,368  Total debt related interest expense paid $ 33,367 $ 33,039 $ 36,368   Debt Modifications, Repurchases and Extinguishments  During the year ended December 31, 2017, the Company incurred issuance costs aggregating $24,307 in connection with the 2017 Debt Facilities. Issuance costs paid to all lenders and third-party fees associated with lenders of the 2017 Debt Facilities who had not participated in the INSW Facilities aggregating $15,067 were capitalized as deferred finance charges. (See Note 2, “Significant Accounting Policies,” for additional information relating to deferred financing charges). Third party fees associated with the First Amendment and with lenders of the 2017 Debt Facilities who had participated in the INSW Facilities aggregating $9,240 , for the year ended December 31, 2017 were expensed and included in third-party debt modification fees in the consolidated statement of operations. In addition, an aggregate net loss of $7,020 for the year ended December 31, 2017 realized on the modification of the Company’s debt facilities, is included in other income/(expense) in the consolidated statement of operations. The net loss reflects a write-off of unamortized original issue discount and deferred financing costs associated with the INSW Facilities, which were treated as partial extinguishments. Issuance costs incurred with respect to the 2017 Debt Facilities have been treated as a reduction of debt proceeds. During the year ended December 31, 2016, the Company paid deferred financing fees of $8,273 in connection with amendments to the INSW Facilities. Such fees were capitalized as deferred finance charges.  During the year ended December 31, 2016, INSW made repurchases of the INSW Term Loan in the open market of $68,922 and mandatory principal prepayments of $83,832 . The aggregate net losses of $1,342 realized on these transactions for the year ended December 31, 2016, is included in other income/(expense) in the consolidated statement of operations. The net loss reflects a $5,097 write-off of unamortized original issue discount and deferred financing costs associated with the principal reductions which were treated as partial extinguishments and a $3,755 discount on repurchase of debt for the year ended December 31, 2016. Third party legal and consulting fees ( aggregating $225 ) incurred by INSW in relation to the open market repurchases are included in general and administrative expenses in consolidated stat ement of operations for the year ended December 31 , 2016.

FAIR VALUE OF FINANCIAL INSTRUM

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES	12 Months Ended
	Dec. 31, 2017
Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures	NOTE 9 — FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES:  The following methods and assumptions were used to estimate the fair value of each class of financial instrument. Cash and cash equivalents and restricted cash— The carrying amounts reported in the consolidated balance sheets for interest-bearing deposits approximate their fair value. Debt— The fair values of the Company’s debt is estimated based on quoted market prices.  Interest rate swaps and caps— The fair values of interest rate swaps and caps are the estimated amounts that the Company would receive or pay to terminate the swaps or caps at the reporting date, which include adjustments for the counterparty or the Company’s credit risk, as appropriate, after taking into consideration any underlying collateral securing the swap or cap agreements. ASC 820, Fair Value Measurements and Disclosures , relating to fair value measurements, defines fair value and established a framework for measuring fair value. The ASC 820 fair value hierarchy distinguishes between market participant assumptions developed based on market data obtained from sources independent of the reporting entity and the reporting entity's own assumptions about market participant assumptions developed based on the best information available in the circumstances. ASC 820 defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date, essentially an exit price. In addition, the fair value of assets and liabilities should include consideration of non-performance risk, which for the liabilities described below includes the Company's own credit risk. The levels of the fair value hierarchy established by ASC 820 are as follows: Level 1—Quoted prices in active markets for identical assets or liabilities Level 2—Quoted prices for similar assets and liabilities in active markets or inputs that are observable Level 3—Inputs that are unobservable (for example cash flow modeling inputs based on assumptions)  The estimated fair values of the Company’s financial instruments, other than derivatives that are not measured at fair value on a recurring basis, categorized based upon the fair value hierarchy, at December 31, 2017 and 2016, are as follows:      Fair Value Level 1 Level 2  December 31, 2017:  Cash and cash equivalents (1) $ 70,606 $ 70,606 $ -  2017 Term Loan Facility (550,689) - (550,689)  2017 Revolver Facility (30,227) (30,227)   December 31, 2016:  Cash and cash equivalents $ 92,001 $ 92,001 $ -  INSW Term Loan (447,888) - (447,888)  (1) Includes non-current restricted cash of $10,579 at December 31, 2017.  Derivatives The Company manages its exposure to interest rate volatility risks by using derivative instruments. Interest Rate Risk The Company uses interest rate caps and swaps for the management of interest rate risk exposure. In December 2017 , the Company entered into an interest rate cap agreement (“Interest Rate Cap”) with a forward start date of Janu ary 1, 201 8 with a major financial institution covering a notional amount of $300,000 to limit the floating interest rate exposure associated with the 2017 Term Loan. The interest rate cap was designated and qualified as a cash flow hedge. This agreement contains no leverage features. The Interest Rate Cap has a Cap Rate of 2.5% through the termination date of December 31, 2020. At December 31, 2016, the Company was party to a similar interest rate cap agreement covering a notional amount of $400,000 to limit the floating interest rate exposure associated with the INSW Term Loan and such agreement expired on February 5, 2017.  Tabular disclosure of derivatives location  D erivatives are recorded in the balance sheet on a net basis by counterparty when a legal right of offset exists. The following tables present information with respect to the fair values of derivatives reflected in the December 31, 2017 and 2016 balance sheets on a gross basis by transaction: Fair Values of Derivative Instruments:     Asset Derivatives Liability Derivatives  Balance Sheet Balance Sheet  Location Amount Location Amount  December 31, 2017:  Derivatives designated as hedging instruments:  Interest rate caps:  Current portion Prepaid expenses and other current assets $ 16 Accounts payable, accrued expenses and other current liabilities $ -  Long-term portion Other assets 886 Other liabilities -  Total derivatives designated as hedging instruments $ 902 $ -   December 31, 2016:  Derivatives designated as hedging instruments:  Interest rate caps:  Long-term portion Other assets $ - Other liabilities $ -  Total derivatives designated as hedging instruments $ - $ -  The following tables present information with respect to gains and losses on derivative positions reflected in the consolidated statements of operations or in the consolidated statements of other comprehensive income/(loss). The effect of cash flow hedging relationships recognized in other comprehensive income/(loss) excluding amounts reclassified from accumulated other comprehensive loss (effective portion), including hedges of equity method investees, for the years ended December 31, 2017, 2016 and 2015 follows:     For the year ended December 31, 2017 2016 2015  Interest rate swaps $ (1,132) $ (3,050) $ (9,721)  Interest rate caps (8) (2) (472)  Total $ (1,140) $ (3,052) $ (10,193)  The effect of cash flow hedging relationships on the consolidated statements of operations is presented excluding hedges of equity method investees. The effect of the Company’s cash flow hedging relationships on the consolidated statement of operations for the years ended December 31, 2017, 2016 and 2015 is shown below:      Statement of Operations  Effective Portion of Gain/(Loss)  Reclassified from Accumulated  Other Comprehensive Loss Ineffective Portion  Amount of Amount of  Location Gain/(Loss) Location Gain/(Loss)  For the year ended December 31, 2017:  Interest rate caps Interest expense $ (131) Interest expense $ -  Total $ (131) $ -   For the year ended December 31, 2016:  Interest rate caps Interest expense $ (517) Interest expense $ -  Total $ (517) $ -   For the year ended December 31, 2015:  Interest rate caps Interest expense $ (2) Interest expense $ -  Total $ (2) $ -      See Note 6 , “Equity Method Investments,” for additional information relating to derivatives held by the Company’s equity method investees and Note 1 4 , “Accumulated Other Comprehensive Loss,” for disclosures relating to the impact of derivative instruments on accumulated other comprehensive loss.  Fair Value Hierarchy  The following table presents the fair values, which are pre-tax, for assets and liabilities measured on a recurring basis (excluding investments in affiliated companies):     Fair Value Level 2  Assets/(Liabilities) at December 31, 2017  Derivative Assets (interest rate caps) $ 902 $ 902 (1)   Assets/(Liabilities) at December 31, 2016  Derivative Assets (interest rate caps) $ - $ - (1) (1) For the interest rate cap, fair value is derived using valuation models that utilize the income valuation approach. These valuation models take into account contract terms such as maturity, as well as other inputs such as interest rate yield curves and creditworthiness of the counterparty and the Company. The following table summarizes the fair values of assets for which an impairment charge was recognized for the year ended December 31, 201 7 :      Impairment  Description Fair Value Level 2 Level 3 Charges  Crude Tankers - Vessels held and used (1) (2) $ 147,584 $ 78,479 $ 69,105 $ (85,626)  Product Carriers - Vessels held and used (1) (2) $ 22,400 $ 22,400 $ - $ (2,782)  (1) Aggregate pre-tax impairment charges of $7,346 related to one vessel in the Crude Tanker segment and two vessels in the Product Carriers segment and $81,062 related to twelve vessels in the International Crude Tanker segment were recorded during the three-month periods ended September 30, 2017 and December 31, 2017, respectively. (2) The fair value measurements aggregating $67,979 at December 31, 2017 used to determine impairment for four vessels and fair value measurements aggregating $32,900 at September 30, 2017 used to determine impairment for three vessels were based upon a market approach, which considered the expected sales prices or scrap values of vessels obtained from vessel appraisals. Because sales of vessels occur somewhat infrequently the expected sales prices are considered to be Level 2. Fair value measurements aggregating $69,105 at December 31, 2017 used to determine the impairment for eight vessels were based on the income approach, which utilized cash flow projections consistent with the most recent projections of the Company and a discount rate equivalent to INSW's weighted average cost of capital. Because the Company uses its own cash flow projections, the cash flow projections are considered to be Level 3. 

ACCOUNTS PAYABLE, ACCRUED EXPEN

ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	12 Months Ended
	Dec. 31, 2017
ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES [Abstract]
ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES	NOTE 10 — ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES:      At December 31, 2017 2016  Accounts payable $ 330 $ 2,866  Payroll and benefits 5,897 5,672  Interest 3,437 4,042  Due to owners on chartered in vessels 867 856  Accrued drydock, repairs and vessel betterment costs 1,838 1,608  Bunkers and lubricants 1,893 2,787  Charter revenues received in advance 918 6,725  Insurance 575 2,650  Accrued vessel expenses 3,369 6,804  Accrued general and administrative expenses 1,599 2,644  Other 2,082 1,583  Total accounts payable, accrued expense and other current liabilities $ 22,805 $ 38,237 

TAXES

TAXES	12 Months Ended
	Dec. 31, 2017
Taxes [Abstract]
Taxes	NOTE 11 —TAXES:  Income taxes are provided using the asset and liability method, such that income taxes are recorded based on amounts refundable or payable in the current year and include the results of any differences in the basis of assets and liabilities between U.S. GAAP and tax reporting. The Company derives substantially all of its gross income from the use and operation of vessels in international commerce. The Company’s entities that own and operate vessels are primarily domiciled in the Marshall Islands, which does not impose income tax on shipping operations. The Company also has or had subsidiaries in various jurisdictions that performed administrative, commercial or technical management functions. These subsidiaries are subject to income taxes based on the services performed in countries in which those particular offices are located and, accordingly, current and deferred income taxes are recorded.  INSW, including its subsidiaries, which are disregarded entities for U.S. Federal income tax purposes, is exempt from taxation on its U.S. source shipping income under Section 883 of the U.S. Internal Revenue Code of 1986, as amended (the “Code”) and U.S. Treasury Department regulations . Under Section 883 of the Code and U.S. Treasury Department regulations, INSW qualified for this exemption because its common shares were treated as primarily and regularly traded on an established securities market in the United States or another qualified country and for more than half of the days in the taxable year ended December 31, 2017 , less than 50 percent of the total vote and value of the Company’s stock was held by one or more shareholders who each owned 5% or more of the vote and value of the Company’s stock . Beginning in 2018, to the extent INSW is unable to qualify for exemption from tax under Section 883, INSW will be subject to U.S. federal taxation of 4% of its U.S. source shipping income on a gross basis without the benefit of deductions. Shipping income that is attributable to transportation that begins or ends, but that does not both begin and end, in the U.S. will be considered to be 50% derived from sources within the U.S. Shipping income attributable to transportation that both begins and ends in the U.S. will be considered to be 100% derived from sources within the U.S. INSW does not engage in transportation that gives rise to 100% U.S. source income. Shipping income attributable to transportation exclusively between non-U.S. ports will be considered to be 100% derived from sources outside the U.S. Shipping income derived from sources outside the U.S. will not be subject to any U.S. federal income tax. INSW’s vessels operate in various parts of the world, including to or from U.S. ports. There can be no assurance that INSW will continue to qualify for the Section 883 exemption.  A substantial portion of income earned by INSW is not subject to income tax, and no deferred taxes are provided on the temporary differences between the tax and financial statement basis of the underlying assets and liabilities for those subsidiaries not subject to income tax in their respective countries of incorporation.  The Marshall Islands impose tonnage taxes, which are assessed on the tonnage of certain of the Company’s vessels. These tonnage taxes are included in vessel expenses in the accompanying consolidated statements of operations.  The components of the income tax provisions follow:      For the year ended December 31, 2017 2016 2015  Current $ 44 $ 440 $ 140  Deferred - - -  Total provision for income taxes $ 44 $ 440 $ 140  The differences between income taxes expected at the Marshall Islands statutory income tax rate of zero percent and the reported income tax provisions are summarized as follows:      For the year ended December 31, 2017 2016 2015  Marshall Islands statutory income tax rate - % - % - %  Change in valuation allowance 0.78 % 25.29 % - %  Liquidation of subsidiaries (0.88) % (29.53) % - %  Income subject to tax in other jurisdictions 0.06 % 1.76 % 0.08 %  Effective income tax rate (0.04) % (2.48) % 0.08 %  The significant components of the Company’s deferred tax liabilities and assets follow:      As of December 31, 2017 2016  Deferred tax assets:  Net operating loss carryforwards $ 1,178 $ 1,711  Excess of tax over book basis of depreciable assets 548 548  Pensions 2,852 3,147  Total deferred tax assets 4,578 5,406  Less: Valuation allowance (4,578) (5,406)  Deferred tax assets, net - -  Net noncurrent deferred tax assets/(liabilities) $ - $ -  As of December 31, 2017 and 2016, the Company had net operating loss carryforwards of $6,931 and $42,001 , respectively. The net operating loss carryforward of $6,931 as of December 31, 2017 ha s an indefinite life.  The Company believes that it is more likely than not that the benefit from its net operating loss carryforwards and certain other deferred tax assets will not be realized and has maintained a valuation allowance of $4,578 and $5,406 , respectively , as of December 31, 201 7 and 201 6 . If or when recognized, the tax benefits related to any reversal of the valuation allowance on deferred tax assets will be accounted for as a reduction of income tax expense in the period such reversal occurs. During 201 7 , the Company decreased its valuation allowance by $828 primari ly as a result of the liquidation of certain subsidiaries .  The following is tabular rollforward of the Company’s unrecognized tax benefits (excluding interest and penalties):      2017 2016  Balance of unrecognized tax benefits as of January 1, $ 153 $ 40  Increases for positions taken in prior years - 115  Decreases for positions taken in prior years - -  Changes due to currency translations - (2)  Balance of unrecognized tax benefits as of December 31, $ 153 $ 153 The Company records interest on unrecognized tax benefits in its provision for income taxes. Accrued interest is included in other current liabilities in the consolidated balance sheets. As of December 31, 2017 and 2016, the Company has recognized a total liability for interest of $51 and $33 , respectively. INSW has recorded the unrecognized tax benefits in other current liabilities in the consolidated balance sheets. If recognized, all of the December 31, 2017 balance of unrecognized tax benefits would affect the effective tax rate. Management believes that it is reasonably possible that a decrease of up to $94 in unrecognized tax benefits related to issues currently under examination by the taxing authorities will be settled during 2018.

RELATED PARTIES

RELATED PARTIES	12 Months Ended
	Dec. 31, 2017
RELATED PARTIES [Abstract]
RELATED PARTIES	NOTE 1 2 —RELATED PARTIES:  The following tables show certain related party transactions between INSW and OSG:     For the year ended December 31, 2017 2016 2015  Corporate overhead allocations from OSG  General and administrative $ - $ 21,486 $ 36,792  Depreciation - 517 730  Separation and transition costs - 6,569 -  Reorganization items, net - 131 5,659  Total corporate overhead allocations from OSG $ - $ 28,703 $ 43,181 Payables to OSG aggregating $367 and $683 as of December 31, 2017 and 2016, respectively, we re primarily in relation to the spin-related agreements described below. A full and final payment of all amounts due to OSG under the spin-related agreements was made during the first quarter of 2018. Transition Services Agreement and Other Spin-off Related Activity  On November 30, 2016, INSW entered into a separation and distribution agreement (the “Separation and Distribution Agreement”) with OSG, which among other things, (i) governed the transfer of assets and liabilities between both entities, (ii) terminated all intercompany arrangements between INSW and OSG except for specified agreements and arrangements, (iii) contained terms and conditions that generally require INSW and OSG to use commercially reasonable efforts to consummate the transactions contemplated by the Separation and Distribution Agreement and the ancillary agreements, (iv) released certain claims between the parties and their affiliates, successors and assigns, (v) contained mutual indemnification provisions and (vi) allocated expenses of the spin-off between the parties. Following the true up of final separation costs between INSW and OSG, income of $64 was recognized during the year ended December 31, 2017 , in conjunction with the Separation and Distribution Agreement .  During the year ended December 31, 2016, spin-off related expenses incurred by INSW pursuant to the Separation and Distribution Agreement aggregated $9,043 . Approximately $3,337 of these costs represented INSW’s allocated share of severance costs for certain individuals that departed OSG in conjunction with the spin-off of INSW. INSW and OSG also entered into a transition services agreement (the “TSA” or “Transition Services Agreement”) pursuant to which both parties agreed to provide each other with specified services for a limited time to help ensure an orderly transition following the Distribution. The Transition Services Agreement specifies the calculation of the costs for these services. Pursuant to the terms of the agreement, OSG provided certain administrative services, including administrative support services related to benefit plans, human resources and legal services, for a transitional period after the spin-off. Similarly, INSW agreed to provide certain limited transition services to OSG, including services relating to accounting activities and information and data provision services. The Transition Services Agreement terminated on June 30, 2017. During the years ended December 31, 2017 and 2016, INSW earned fees totaling $63 and $27 , respectively for services provided to OSG pursuant to the terms of the Transition Services Agreement. During the years ended December 31, 2017 and 2016, INSW also incurred fees totaling $731 and $31 , respectively, for services receiv ed from OSG, including INSW’s share of the compensation costs of former OSG corporate employees providing services to one or both companies during the defined transitional period, which ended on June 30, 2017.  INSW and OSG also entered into an employee matters agreement (the “Employee Matters Agreement”), which addresse d the allocation and treatment of assets and liabilities relating to employees and compensation and benefit plans and programs in which INSW employees participated, including equity incentive plans. The Employee Matters Agreement also governs the transfer of employees between OSG and INSW in connection with the Distribution, and set forth certain obligations for reimbursements and indemnities between OSG and INSW.  Corporate Overhead Allocations from OSG  During the periods presented, the Company benefited from certain corporate functions provided by OSG. In addition, certain entities within INSW incurred similar costs in respect of corporate functions that provided services to non-INSW subsidiaries of OSG. An allocation of these corporate expenses, including legal costs related to certain litigation undertaken by OSG, has been reflected in the consolidated financial statements in general and administrative expenses, depreciation and amortization and reorganization items, net. Income earned directly by OSG is not subject to allocation because it is not directly related to the INSW business. Reorganization items, net for the year ended December 31, 2016, includes a credit for the recovery of costs allocated to INSW in prior years related to certain litigation undertaken by OSG that was settled by OSG in February 2016. Guarantees The FSO Joint Venture is a party to a number of contracts: (a) the FSO Joint Venture is an obligor pursuant to a guarantee facility agreement dated as of July 14, 2017, by and among the FSO Joint Venture, ING Belgium NV/SA, as issuing bank, and Euronav and INSW, as guarantors (the ‘‘Guarantee Facility’’); and (b) the FSO Joint Venture is party to two service contracts with NOC (the ‘‘NOC Service Contracts’’). INSW severally guarantees the obligations of the FSO Joint Venture pursuant to the Guarantee Facility and severally guaranteed the obligations of the FSO Joint Venture to Maersk Oil Qatar AS (“MOQ”) under the MOQ service contracts, which contracts were novated to NOC in July 2017 (the ‘‘MOQ Guarantee’’) and severally guarantees the obligations of the FSO Joint Venture under the NOC Service Contracts. INSW continues the MOQ Guarantee for the period ended on the novation date of the service contracts for MOQ, which guarantee will end when the Qatari authorities determine that the FSO Joint Venture has paid all Qatari taxes owed by the FSO Joint Venture under such service contracts for tax periods through the novation date.  INSW maintains a guarantee in favor of Qatar Liquefied Gas Company Limited (2) (‘‘LNG Charterer’’) relating to certain LNG Tanker Time Charter Party Agreements with the LNG Charterer and each of Overseas LNG H1 Corporation, Overseas LNG H2 Corporation, Overseas LNG S1 Corporation and Overseas LNG S2 Corporation (such agreements, the ‘‘LNG Charter Party Agreements,’’ and such guarantee, the ‘‘LNG Performance Guarantee’’). INSW will pay QGTC an annual fee of $100 until such time that QGTC ceases to provide a guarantee in favor of the LNG charterer relating to performance under the LNG Charter Party Agreements.  OSG continues to provide a guarantee in favor of the LNG Charterer relating to the LNG Charter Party Agreements (such guarantees, the ‘‘OSG LNG Performance Guarantee’’). INSW will indemnify OSG for liabilities arising from the OSG LNG Performance Guarantee pursuant to the terms of the Separation and Distribution Agreement. In connection with the OSG LNG Performance Guarantee, INSW pays a $125 fee per year to OSG, which will increase to $135 per year in 2018 and will be terminated if OSG ceases to provide the OSG LNG Performance Guarantee.  Capital Contributions from OSG and Dividends Paid to OSG For the year ended December 31, 2016, the Company recorded capital contributions from OSG of $3,797 comprised of allocated reorganization items, net of $131 , non-cash expense relating to stock compensation benefits of $2,520 and certain allocated general and administrative costs of $1,146 . For the year ended December 31, 2015, the Company recorded capital contributions from OSG of $9,424 , comprised of allocated reorganizations items, net of $5,659 , non-cash expense relating to stock compensation benefits of $2,811 , certain allocated general and administrative expenses of $954. For additional information relating to stock compensation benefits see Note 1 3 , “Capital Stock and Stock Compensation.”  During the years ended December 31, 2016 and 2015, INSW made dividend distributions to OSG totaling $202,000 (or $6.93 per share) and $200,000 (or $6.86 per share), respectively.

CAPITAL STOCK AND STOCK COMPENS

CAPITAL STOCK AND STOCK COMPENSATION	12 Months Ended
	Dec. 31, 2017
Capital Stock and Stock Compensation [Abstract]
Capital Stock and Stock Compensation	NOTE 13 — CAPITAL STOCK AND STOCK COMPENSATION:  The Company accounts for stock compensation expense in accordance with the fair value based method required by ASC 718, Compensation – Stock Compensation . Such fair value based method requires share based payment transactions to be measured based on the fair value of the equity instruments issued.  In connection with the spin-off, effective November 18, 2016 INSW adopted, and OSG as its sole stockholder approved, incentive compensation plans (the “Incentive Plans” as further described below) in order to facilitate the grant of equity and cash incentives to directors, employees, including executive officers and consultants of the Company and certain of its affiliates and to enable the Company and certain of its affiliates to obtain and retain the services of these individuals, which is essential to our long-term success. INSW reserved 2,000,000 shares for issuance under its management incentive plan and 400,000 shares for issuance under its non-employee director incentive compensation plan.  OSG maintains or maintained various stock-based compensation arrangements (the “OSG Incentive Plans” and the “OSG 2004 Stock Incentive Plan” ), under which it provided awards to certain employees of INSW of restricted common stock, restricted stock units, performance restricted stock units and stock options to purchase shares of OSG. Because INSW provided employee services in consideration for the participation of INSW’s employees in these plans, a share-based compensation expense for the awards granted to INSW’s employees has been reflected in the consolidated statement of operations. Furthermore, the restricted stock, restricted stock unit and stock option grants also relate to individuals that are considered to be employees of OSG or directors of OSG . Compensation expense relating to such grants is a component of general and administrative expense on OSG’s consolidated statement of operations and as a result for periods prior to our spin-off from OSG was subject to the cost allocation procedures described in Note 12, “Related Parties.”  Each OSG restricted stock unit and performance restricted stock unit that was unvested and outstanding immediately prior to the effective time of our spin off from OSG ( the “Effective Time” ) and held by an INSW Group Employee (as defined by the Employee Matters Agreement) was converted as of the Effective Time into an INSW restricted stock unit or INSW performance restricted stock unit, respectively. Each OSG stock option to purchase shares of OSG that was outstanding immediately prior to the Effective Time and held by an INSW Group Employee was converted as of the Effective Time into an INSW stock option.  The OSG Incentive Plans contained anti-dilution provisions whereby in the event of any change in the capitalization of OSG, the number and type of securities underlying outstanding share based payment awards were to be adjusted, as appropriate, in order to prevent dilution or enlargement of rights. The impact of these provisions resulted in a modification of all outstanding share based payment awards held by INSW Group Employees upon the spinoff transaction. As the fair value of the INSW restricted stock unit or INSW performance restricted stock unit awards and the INSW stock option awards immediately after the spinoff transaction increased when compared to the fair value of the equivalent OSG awards held by INSW Group Employees immediately prior to the spinoff transactions, incremental compensation costs of approximately $427 will be recognized by INSW over the remaining vesting period of such awards as a result of the spinoff modifications. As of December 31, 2017, approximately $124 of such costs remain unamortized.  Information regarding share-based compensation awards granted by INSW follows:  Director Compensation — Restricted Common Stock  INSW awarded a total of 38,938 and 32,067 restricted common stock shares during the years ended December 31, 2017 and 2016 to its non-employee directors. The weighted average fair value of INSW’s stock on the measurement date of such awards was $20.03 (2017) and $13.72 (2016) per share. Such restricted shares awards vest in full on the earlier of the next annual meeti ng of the stockholders or anniversary date , subject to each director continuing to provide services to INSW through such date. The restricted share awards granted may not be transferred, pledged, assigned or otherwise encumbered prior to vesting. Prior to the vesting date, a holder of restricted share awards has all the rights of a shareholder of INSW, including the right to vote such shares and the right to receive dividends paid with respect to such shares at the same time as common shareholders generally.  Management Compensation  Capitalized terms that follow are defined herein or in the Employee Matters Agreement.  (i) Restricted Stock Units  During the years ended December 31, 2017, 2016 and 2015, the Company awarded 66,503 , 76,585 and 0 time-based restricted stock units (“RSUs”) to certain of its employees, including senior officers, respectively. The average grant date fair value of these awards was $18.91 (2017) and $15.00 (2016) per RSU. Each RSU represents a contingent right to receive one share of INSW common stock upon vesting. Each award of RSUs will vest in equal installments on each of the first three anniversaries of the grant date. RSUs may not be transferred, pledged, assigned or otherwise encumbered until they are settled. Settlement of vested RSUs may be in either shares of common stock or cash, as determined at the discretion of the Human Resources and Compensation Committee, and shall occur as soon as practicable after the vesting date. If the RSUs are settled in shares of common stock, following the settlement of such shares, the grantee will be th e record owner of the shares of common stock and will have all the rights of a shareholder of the Company, including the right to vote such shares and the right to receive dividends paid with respect to such shares of common stock. RSUs which have not become vested as of the date of a grantee’s termination from the Company will be forfeited without the payment of any consideration, unless otherwise provided for.  During the year ended December 31, 2017 the Company awarded 30,856 performance-based RSUs to its senior officers. Each performance stock unit represents a contingent right to receive RSUs based upon the covered employees being continuously employed through the end of the period over which the performance goals are measured and shall vest as follows: (i) one-third of the target RSUs shall vest on December 31, 2019, subject to INSW’s three-year earnings per share (“EPS”) performance in the three-year EPS performance period relative to a target (the “EPS Target”) set forth in the award agreements; (ii) one-third of the target RSUs shall vest on December 31, 2019, subject to INSW’s return on invested capital (“ROIC”) performance in the three-year ROIC performance period relative to a target rate (the “ROIC Target”) set forth in the award agreements; and (iii) one-third of the target RSUs will be subject to INSW’s three-year total shareholder return (“TSR”) performance relative to that of a performance peer group over a three-year performance period (“TSR Target”). Vesting is subject in each case to the Human Resources and Compensation Committee of the Company’s Board of Directors’ certification of achievement of the performance measures and targets no later than March 15, 2020. The EPS Target and ROIC Target are performance conditions which, as of December 31, 2017, INSW management believes, are not yet considered probable of being achieved. Accordingly, for financial reporting purposes, no compensation costs will be recognized for these awards until it becomes probable that the performance conditions will be achieved. The weighted average grant date fair value of the awards with performance conditions was determined to be $19.73 per RSU. The weighted average grant date fair value of the TSR based performance awards, which have a market condition, was estimated using a Monte Carlo probability model and determined to be $24.35 per RSU. In addition, during the year ended December 31, 2017, INSW granted 29,206 performance-based RSUs ( 11,383 of which represented the 2017 tranche of the awards originally made on October 12, 2015) to certain members of its senior management. The grant date fair value of the performance awards was determined to be $19.13 per RSU. Each performance stock unit represents a contingent right to receive RSUs based upon certain performance related goals being met and the covered employees being continuously employed through the end of the period over which the performance goals are measured. These performance awards which are vested on December 31, 2017, are subject to INSW’s ROIC performance for the year ended December 31, 2017 relative to a target rate set forth in the award agreements. Vesting is subject in each case to the Human Resources and Compensation Committee of the Company’s Board of Directors’ certification of achievement of the performance measures and targets no later than March 31, 2018. The performance condition in this award was achieved and resulted in payouts ranging from 130% to 150% of target. During the year ended December 31 , 2016 the Company awarded 33,709 performance-based RSUs to its senior officers to replace non-vested OSG performance-based RSUs awarded by OSG. Of this amount, 24,953 performance-based RSUs represent a contingent right to receive INSW RSUs based upon the covered employees being continuously employed through December 31, 2018. The grant date fair value of the TSR based performance awards, which has a market condition, was determined to be $15.00 per INSW RSU. On March 29, 2017, pursuant to the terms of the INSW Management Equity Incentive Plan and the Employee Matters Agreement with OSG, the Human Resources and Compensation Committee of the Company’s Board of Directors adjusted the applicable performance metrics for the OSG performance based units held by certain members of senior management that had been converted into INSW performance based units as of the November 30, 2016 spin-off date. The performance metrics were modified as follows: (i) one-third of the target RSUs shall vest on December 31, 2018, subject to INSW’s three-year EPS performance in the three-year EPS performance period relative to the same compounded annual growth rate (the “Modified EPS Target”) set forth in the original OSG award agreements; (ii) one-third of the target RSUs shall vest on December 31, 2018, subject to a proportionate average of OSG’s ROIC performance for the first eleven months and INSW’s ROIC performance for the last twenty-five months of the three-year ROIC performance period relative to the same target rate used under the original OSG award agreements (the “Modified ROIC Target”); and (iii) one-third of the target RSUs will be subject to a three-year TSR performance relative to that of the same performance peer group used under the original OSG award, over a three-year TSR performance period (“Modified TSR Target”). The TSR performance shall be measured using a proportionate average of the TSR performance of OSG for the first eleven months and INSW’s TSR performance for the last twenty-five months in the three-year TSR performance period. The modifications to the awards with performance conditions (EPS and ROIC Target awards) did not result in incremental compensation cost as these performance targets are not yet considered probable of being achieved. The modification of the TSR Target award resulted in incremental compensation expense of $124, which will be recognized over the remaining performance period of the awards. The Modified EPS Target and Modified ROIC Target are performance condition s which, as of December 31, 2017 , INSW management believes, are not yet considered probable of being achieved. Accordingly, for financial reporting purposes, no compensation costs will be recognized for the portion of these awards relating to performance conditions until it becomes probable that the performance conditions will be achieved. Settlement of the vested INSW performance-based RSUs may be in either shares of common stock or cash, as determined by the Human Resources and Compensation Committee in its discretion, and shall occur as soon as practicable after the vesting date.  (ii) Stock Options  During the years ended December 31, 2017 and 2016, the Company awarded to certain senior officers an aggregate of 148,271 and 127,559 stock options, respectively. Each stock option represents an option to purchase one share of INSW common stock for an exercise price that ranged between $18.21 and $22.42 per share for options granted in 2017 and between $19.04 and $30.93 per share for options granted in 2016 . The weighted average grant date fair value of the options granted in 2017 was $8.48 per option. The weighted average grant date fair value of the options granted in 2016 as a result of the conversion of corresponding OSG stock options originally granted in 2016, 2015 and 2014 were $4.55 , $2.26 and $1.86 , respectively. Stock options may not be transferred, pledged, assigned or otherwise encumbered prior to vesting. Each stock option will vest in equal installments on each of the first three anniversaries of the award date. The stock options expire on the business day immediately preceding the tenth anniversary of the award date. If a stock option grantee’s employment is terminated for cause (as defined in the applicable Form of Grant Agreement), stock options (whether then vested or exercisable or not) will lapse and will not be exercisable. If a stock option grantee’s employment is terminated for reasons other than cause, the option recipient may exercise the vested portion of the stock option but only within such period of time ending on the earlier to occur of (i) the 90th day ending after the option recipient’s employment terminated and (ii) the expiration of the options, provided that if the Optionee’s employment terminates for death or disability the vested portion of the option may be exercised until the earlier of (i) the first anniversary of employment termination and (ii) the expiration date of the options.  The fair values of the options granted in 2017 were estimated using the Black-Scholes option pricing model with inputs that include the INSW stock price, the INSW exercise price and the following weighted average assumptions: risk free interest rates ranging from 1.95% to 2.11% , dividend yields of 0.0% , expected stock price volatility factor of .44 , and expected lives at inception of six years, respectively.  The fair value of the options granted in 2016 were estimated using the Black-Scholes option pricing model with inputs including the INSW stock v alue based on weighted average per share price of INSW common stock for the 20 Trading Days following the Distribution Date, the INSW exercise price and the following weighted average assumptions for the converted OSG Option originally granted in 2016, 2015 and 2014: risk free interest rates of 2.18% , 1.79% and 1.79% , respectively, dividend yields of 0.0% , expected stock price volatility factor of .40 , and expected lives at inception of five years, four years and four years, respectively.  Share Repurchases In connection with the settlement of vested restricted stock units, the Company repurchased 13,961 shares of common stock during year ended December 31, 2017 at an average cost of $18.66 per share (based on the market prices on the dates of vesting) from certain members of management to cover withholding taxes. In January 2018, an additional 4,989 shares of common stock were repurchased from certain employees and members of management at an average cost of $17.81 per share to cover withholding taxes paid in December 2017. On May 2, 2017, the Company’s Board of Directors approved a resolution authorizing the Company to implement a stock repurchase program. Under the program, the Company may opportunistically repurchase up to $30,000 worth of shares of the Company’s common stock from time to time over a 24-month period, on the open market or otherwise, in such quantities, at such prices, in such manner and on such terms and conditions as management determines is in the best interests of the Company. Shares owned by employees, directors and other affiliates of the Company will not be eligible for repurchase under this program without further authorization from the Board. During the year ended December 31, 2017, the Company repurchased and retired 160,000 shares of its common stock in open-market purchases at an average price of $19.86 per share, for a total cost of $3,177 . Activity with respect to restricted common stock and restricted stock units under INSW compensation plans is summarized as follows:      Activity for the three years ended December 31, 2017 Common Stock   Nonvested Shares Outstanding at December 31, 2015 -  RSUs issued to replace OSG RSUs 110,294  Granted 32,067  Vested ( $19.04 per share) (1) (25,103)  Nonvested Shares Outstanding at December 31, 2016 117,258  Granted 165,503  Vested ( $18.21 - $19.13 per share) (1) (108,584)  Nonvested Shares Outstanding at December 31, 2017 174,177 (1) Includes 6,508 (2016) and 12,442 (2017) shares of common stock forfeited by employees to cover withholding taxes.  Activity with respect to stock options under INSW compensation plans is summarized as follows:    Activity for the three years ended December 31, 2017 Common Stock   Options Outstanding at December 31, 2015 -  Options issued to replace OSG options 127,559  Exercised -  Options Outstanding at December 31, 2016 127,559  Granted 148,271  Exercised -  Options Outstanding at December 31, 2017 275,830  Options Exercisable at December 31, 2017 95,618  The weighted average remaining contractual life of the outstanding and exercisable stock options at December 31, 2017 was 8.54 years and 7.96 yea rs, respectively . The range of exercise prices of the stock options outstanding at December 31, 2017 was between $18.21 and $30.93 per share. The weighted average exercise price of the stock options outstanding and exercisable at Decembe r 31, 2017 was $21.09 and $23.65, respectively . The aggregate intrinsic value of the INSW stock options outstanding and exercisable at December 31, 2017 was $20 and $7 , respectively. Compensation expense is recognized over the vesting period applicable to each grant, using the straight-line method.  Direct and allocated compensation expense with respect to restricted common stock and restricted stock units outstanding for t he years ended December 31, 2017, 2016 and 201 5 was $2,982 , $2,157 and $2,380 , respectively. The allocated compensation expense in 2016 and 2015 was recorded as a capital contribution from OSG as such amount was not settled in cash.  Direct and allocated compensation expense relating to stock options recorded by INSW for t he years ended December 31, 2017 , 201 6 and 201 5 was $826 , $684 and $431 , respectively. The allocated compensation expense has been recorded as a capital contribution from OSG as such amount will not be settled in cash.  As of December 31, 2017 , there was $3,066 of unrecognized compensation cost related to INSW nonvested share-based compensation arrangements. That cost is expected to be recognized over a weighted average period of 1.64 years .

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Loss [Abstract]
Accumulated Other Comprehensive Loss	NOTE 14 —ACCUMULATED OTHER COMPREHENSIVE LOSS:  The components of accumulated other comprehensive loss, net of related taxes, in the consolidated balance sheets follow:      At December 31, 2017 2016  Unrealized losses on derivative instruments $ (28,989) $ (40,317)  Items not yet recognized as a component of net periodic benefit cost (pension plans) (11,418) (11,950)  $ (40,407) $ (52,267)  The following tables present the changes in the balances of each component of accumulated other comprehensive loss, net of related taxes, for the three years ended December 31, 2017.     Unrealized losses on cash flow hedges Items not yet recognized as a component of net periodic benefit cost (pension plans) Foreign currency translation adjustment Total   Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (1,140) 17 - (1,123)  Amounts reclassified from accumulated other  comprehensive loss 12,468 515 - 12,983  Total change in accumulated other comprehensive loss 11,328 532 - 11,860  Balance at December 31, 2017 $ (28,989) $ (11,418) $ - $ (40,407)   Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (3,052) (2,364) 42 (5,374)  Amounts reclassified from accumulated other  comprehensive loss 16,181 1,050 - 17,231  Total change in accumulated other comprehensive loss 13,129 (1,314) 42 11,857  Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)   Balance at December 31, 2014 $ (61,356) $ (12,988) $ (29) $ (74,373)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (10,193) 1,870 (13) (8,336)  Amounts reclassified from accumulated other  comprehensive loss 18,103 482 - 18,585  Total change in accumulated other comprehensive loss 7,910 2,352 (13) 10,249  Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124)  The following table presents information with respect to amounts reclassified out of accumulated other comprehensive loss for the three years ended December 31, 2017.    Years Ended December 31,  Accumulated Other Comprehensive Loss Component 2017 2016 2015 Statement of Operations Line Item   Unrealized losses on cash flow hedges:  Interest rate swaps entered into by the Company's Equity in income of  equity method joint venture investees $ (12,337) $ (15,664) $ (18,101) affiliated companies   Interest rate caps entered into by the Company's  subsidiaries (131) (517) (2) Interest expense   Items not yet recognized as a component of net  periodic benefit cost (pension plans):  Net periodic benefit costs associated with  pension and postretirement benefit plans for General and  shore-based employees (515) (1,050) (482) administrative expenses  $ (12,983) $ (17,231) $ (18,585) Total before and net of tax  The following amounts are included in accumulated other comprehensive loss at December 31, 201 7 , which have not yet been recognized in net periodic cost: unrecognized prior service costs of $1,467 ( $1,100 net of tax) and unrecognized actuarial losses of $11,734 ($ 10,318 net of tax). The prior service costs and actuarial loss es included in accumulated other comprehensive loss and expected to be recognized in net pe riodic cost during 201 8 are losses of $70 (gross and net of tax) and $408 (gross and net of tax), respectively.  At December 31, 2017 , the Company expects that it will reclassify $8,509 (gross and net of tax) of net losses on derivative instruments from accumulated other comprehensive loss to earnings during the next twelve months due to the payment of variable rate interest associated with floating rate debt of INSW’s LNG equity method investees and the interest rate cap held by the Company.  See Note 6 , “Equity Method Investments,” for additional information relating to derivatives held by the Company’s equity method investees and Note 9 , “Fair Value of Financial Instruments, Derivatives and Fair Value,” for additional disclosures relating to derivative instruments. 

LEASES

LEASES	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Leases	NOTE 15 — LEASES:  1. Charters-in:  As of December 31, 2017 , the Company had commitments to charter-in six MR vessels. All of the charters-in, of which two are bareboat charters with expiry dates ranging from April 201 8 to June 2018 and four are time charters with expiry dates ranging from June 2018 to July 2018, are accounted for as operating leases. Lease expense relating to charters-in is included in charter hire expenses in the consolidated statements of operations.  The future minimum commitments and related number of operating days under these operating leases are as follows:      Bareboat Charters-in:   At December 31, 2017 Amount Operating Days  2018 $ 1,841 279  Net minimum lease payments $ 1,841 279 Time Charters-in:      At December 31, 2017 Amount Operating Days  2018 $ 11,849 1,218  Net minimum lease payments $ 11,849 1,218 The future minimum commitments for time charters-in exclude amounts with respect to vessels chartered-in where the duration of the charter was one year or less at inception but include amounts with respect to workboats employed in the Crude Tankers Lightering business which are cancellable upon 180 d ays ’ notice. Time charters-in commitments have been reduced to reflect estimated days that the vessels will not be available for employment due to drydock because INSW does not pay charter hire when time chartered-in vessels are not available for its use. Certain of the cha rters in the above tables provide INSW with renewal options. 2. Charters-out: The future minimum revenues, before reduction for brokerage commissions, expected to be received on noncancelable time charters and the related revenue days (revenue days represent calendar days, less days that vessels are not available for employment due to repairs, drydock or lay-up) are as follows:      At December 31, 2017 Amount Revenue Days  2018 $ 6,218 604  Future minimum revenues $ 6,218 604 Future minimum revenues do not include (i) the Company’s share of time charters entered into by the pools in which it participates, (ii) the Company’s share of time charters entered into by the joint ventures, which the Company accounts for under the equity method. Revenues from a time charter are not generally received when a vessel is off-hire, including time required for normal periodic maintenance of the vessel. In arriving at the minimum future charter revenues, an estimated time off-hire to perform periodic maintenance on each vessel has been deducted, although there is no assurance that such estimate will be reflective of the actual off-hire in the future. 3. Office space: The future minimum commitments under all lease obligations for office space are as follows:      At December 31, Amount  2018 $ 1,249  2019 1,166  2020 1,152  2021 665  Net minimum lease payments $ 4,232 

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS	12 Months Ended
	Dec. 31, 2017
Pension and Other Postretirement Benefit Plans [Abstract]
Pension and Other Postretirement Benefit Plans	NOTE 16 —PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS:  Pension plans  The Company has obligations outstanding under a defined benefit pension plan in the UK. The plan provides defined benefits based on years of service and final average salary. The plan was closed to new entrants and accrual from December 2007. The Company has provided a guarantee to the trustees of the OSG Ship Management (UK) Ltd. Retirement Benefits Plan (the “Scheme”) in the amount of the unfunded deficiency calculated on a solvency basis, if the principal employer fails to make the required periodic contributions to the Scheme.  Information with respect to the Scheme for which INSW uses a December 31 measurement date, is as follows:      Pension Benefits  At December 31, 2017 2016  Change in benefit obligation:  Benefit obligation at beginning of year $ 29,240 $ 29,899  Interest cost on benefit obligation 797 932  Actuarial losses/(gains) (519) 5,525  Benefits paid (770) (603)  Settlements - (1,579)  Foreign exchange losses/(gains) 2,779 (4,934)  Benefit obligation at year end 31,527 29,240   Change in plan assets:  Fair value of plan assets at beginning of year 25,466 21,090  Actual return on plan assets 1,714 2,503  Employer contributions 787 7,605  Benefits paid (770) (603)  Settlements - (1,775)  Plan administration costs (64) -  Foreign exchange (gains)/losses 2,394 (3,354)  Fair value of plan assets at year end 29,527 25,466  Unfunded status at December 31 $ (2,000) $ (3,774) The unfunded benefit obligation for the pension plan is included in other liabilities in the consolidated balance sheets. Information for the defined benefit pension plan with accumulated benefit obligations in excess of plan assets follows:      At December 31, 2017 2016  Projected benefit obligation $ 31,527 $ 29,240  Accumulated benefit obligation 31,527 29,240  Fair value of plan assets 29,527 25,466       Pension benefits  For the year ended December 31, 2017 2016 2015  Components of expense:  Plan administration costs $ 64 $ - $ -  Interest cost on benefit obligation 797 886 1,164  Expected return on plan assets (1,041) (951) (1,159)  Amortization of prior-service costs 68 67 79  Recognized net actuarial loss 447 343 403  Recognized settlement loss - 640 -  Net periodic benefit cost $ 335 $ 985 $ 487  Unrecognized actuarial losses are amortized over a period of twenty-one years, which represents the term to retirement of the youngest member of the Scheme.  The weighted-average assumptions used to determine benefit obligations follow:     Pension benefits  At December 31, 2017 2016  Discount rate 2.40% 2.60%   The selection of a single discount rate for the defined benefit plan was derived from bond yield curves, which the Company believed as of such dates to be appropriate for the plan, reflecting the length of the liabilities and the yields obtainable on investment grade bonds. The assumption for a long-term rate of return on assets was based on a weighted average of rates of return on the investment sectors in which the assets are invested.  The weighted-average assumptions used to determine net periodic benefit costs follow:       Pension benefits  For the year ended December 31, 2017 2016 2015  Discount rate 2.60% 3.80% 3.55%  Expected (long-term) return on plan assets 3.85% 5.62% 5.35%  Rate of future compensation increases - - -  Expected benefit payments are as follows:       Pension benefits  2018 $ 667  2019 700  2020 735  2021 772  2022 810  Years 2023-2027 4,703  $ 8,387 The fair values of the Company’s pension plan assets at December 31, 2017, by asset category are as follows:      Description Fair Value Level 1 Level 2 (1)  Cash and cash equivalents $ 971 $ 971 $ -  Managed fund 28,556 - 28,556  Total $ 29,527 $ 971 $ 28,556   (1) Quoted prices for the managed fund is not available from an active market source since such investments are pooled investment funds. The unitized pooled investment vehicles have been valued at the latest available bid price or single price provided by the pooled investment manager. Shares in other pooled arrangements have been valued at the latest available net asset value, determined in accordance with fair value principles, provided by the pooled investment manager. Management has historically maintained a targeted allocation of between 86% and 90% of the Scheme assets in an equity fund index and between 10% and 14% in an over 15-year Gilt index fund. During 2017 , in connection with a transition from passive investments funds to actively managed investment funds, the allocation was amended to better reflect the liabilities of the Scheme. An allocation of 67% is now maintained with return seeking assets, with the balance of 33% invested in liability driven investments to target a 100% match to interest rate risks (by asset value) .  The Company contributed $787 , $7,605 and $1,161 to the UK Scheme in 2017, 2016 and 2015, respectively. The Company expects that its contribution to the UK Scheme in 2018 will be approximately $810 . Defined Contribution Plans The Company has defined contribution plans covering all eligible shore-based employees in the U.K. and U.S . Contributions are limited to amounts allowable for income tax purposes and include employer matching contributions to the plans. All contributions to the plans are at the discretion of the Company or as mandated by statutory laws . The contributions to the plan s during the three years ended December 31, 201 7 were not material.  The expenses directly attributable to INSW’s employees for these defined contribution plans for each of t he years ended December 31, 2017 , 201 6 and 201 5 were not material.

OTHER INCOME_(EXPENSE)

OTHER INCOME/(EXPENSE)	12 Months Ended
	Dec. 31, 2017
OTHER INCOME/(EXPENSE) [Abstract]
OTHER INCOME/(EXPENSE)	NOTE 17 — OTHER (EXPENSE)/ INCOME :      For the year ended December 31, 2017 2016 2015  Investment income:  Interest $ 676 $ 376 $ 66  676 376 66  Write-off of deferred financing costs (7,020) (5,097) -  Discount on repurchase of debt - 3,755 -  $ (6,344) $ (966) $ 66  Refer to Note 8 , “ Debt ,” for additional information relating to write-off of deferred financing costs and discount on repurchase of debt .

REORGANIZATION ITEMS, NET

REORGANIZATION ITEMS, NET	12 Months Ended
	Dec. 31, 2017
REORGANIZATION ITEMS, NET [Abstract]
REORGANIZATION ITEMS, NET	NOTE 18 — REORGANIZATION ITEMS, NET: On November 14, 2012 (the “Petition Date”), OSG and 180 of its subsidiaries including INSW Debtor entities, filed voluntary petitions for reorganization under Chapter 11 of the U.S. Code (the “Bankruptcy Code”) in the U.S. Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”). The Debtors filed with the Bankruptcy Court a plan of reorganization which was subsequently confirmed by the Bankruptcy Court’s order entered on July 18, 2014. On August 5, 2014 (the “Effective Date”), the plan of reorganization became effective and OSG and its affiliated debtors, including INSW Debtor entities, emerged from bankruptcy. On February 10, 2017, pursuant to a final decree and order of the Bankruptcy Court, OSG’s one remaining case, as the parent company, was closed.  Reorganization items, net represent amounts incurred subsequent to the bankruptcy date as a direct result of the filing of the Chapter 11 cases. The table below reflects the recovery of previously allocated professional fees associated with a litigation matter that OSG subsequently settled for an amount in excess of its related out-of-pocket expenses.     For the year ended December 31, 2017 2016 2015  Allocated trustee fees $ - $ 74 $ 147  Allocated professional fees - (3,220) 5,422  Other claim adjustments - 3,277 90  $ - $ 131 $ 5,659  The table above reflects the recovery of previously allocated professional fees associated with a litigation matter that OSG subsequently settled for an amount in excess of its related out-of-pocket expenses during 2016.  No cash was paid for reorganization items for the years ended December 31, 201 7, 201 6 and 201 5. For the years ended December 31, 2016 and 201 5, the allocation of non-cash reorganization expenses of $131 , and $5,659 , respectively, were recorded as capital contributions from OSG.

2017 AND 2016 QUARTERLY RESULTS

2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS	12 Months Ended
	Dec. 31, 2017
2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS [Abstract]
2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS	NOTE 19 — 2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS (UNAUDITED):       Selected Financial Data for the Quarter Ended March 31, June 30, Sept. 30, Dec. 31,  2017  Shipping revenues $ 88,750 $ 71,957 $ 59,968 $ 69,426  Loss on disposal of vessels and other property, including impairments - - (5,406) (81,449)  Income/(loss) from vessel operations 13,344 (9,645) (23,749) (88,178)  Interest expense (8,965) (9,076) (11,030) (11,367)  Income tax benefit/(provision) (4) (4) (23) (13)  Net income/(loss) 18,067 (11,619) (21,816) (90,720)   Basic and Diluted net income/(loss) per share $ 0.62 $ (0.40) $ (0.75) $ (3.12)     Selected Financial Data for the Quarter Ended March 31, June 30, Sept. 30, Dec. 31,  2016  Shipping revenues $ 128,676 $ 103,062 $ 80,771 $ 85,810  Gain/(loss) on disposal of vessels and other property, including impairments 171 - (49,640) (29,734)  Income/(loss) from vessel operations 53,129 29,079 (47,758) (28,509)  Interest expense (10,742) (9,690) (9,519) (9,525)  Reorganization items, net 4,471 (520) (3,849) (233)  Income tax benefit/(provision) (4) (173) 20 (283)  Net income/(loss) 59,890 30,506 (50,862) (57,757)   Basic and Diluted net income/(loss) per share $ 2.05 $ 1.05 $ (1.74) $ (1.98)

CONTINGENCIES

CONTINGENCIES	12 Months Ended
	Dec. 31, 2017
Contingencies [Abstract]
Contingencies	NOTE 20 — CONTINGENCIES:  INSW’s policy for recording legal costs related to contingencies is to expense such legal costs as incurred.  Multi-Employer Plans The Merchant Navy Officers Pension Fund (“MNOPF”) is a multi-employer defined benefit pension plan covering British crew members that served as officers on board INSW’s vessels (as well as vessels of other owners). The trustees of the plan have indicated that, under the terms of the High Court ruling in 2005, which established the liability of past employers to fund the deficit on the Post 1978 section of MNOPF, calls for further contributions may be required if additional actuarial deficits arise or if other employers liable for contributions are not able to pay their share in the future. As the amount of any such assessment cannot currently be reasonably estimated, no reserves have been recorded for this contingency in INSW’s consolidated financial statements as of December 31, 2017. The next deficit valuation is due March 31, 2018. The Merchant Navy Ratings Pension Fund (“MNRPF”) is a multi-employer defined benefit pension plan covering British crew members that served as ratings (seamen) on board INSW’s vessels (as well as vessels of other owners) more than 20 years ago. During 2014 the trustees of the MNRPF sought court approval for a new deficit reduction regime for participating employers. Participating employers include current employers, historic employers that have made voluntary contributions, and historic employers such as INSW that have made no deficit contributions. The trustees received court approval of the new deficit reduction regime in February 2015 and INSW received an assessment of $1,487 which was recorded in June 2015, of which £639 ( $988 ) was paid in October 2015 and the balance was paid on October 25, 2016. Calls for further contributions may be required if additional actuarial deficits arise or if other employers liable for contributions are unable to pay their share in the future. Based on the latest estimated deficit valuation using a measurement date of March 31, 2017, which was distributed to employers in June 2017, INSW recorded a reserve of £290 ( $388 ) for a potential assessment by the trustees of the MNRPF as of December 31, 2017.  Galveston In late September 2017, an industrial accident at a leased facility in Galveston resulted in fatalities to two temporary employees. In accordance with law, an investigation of the accident is currently underway by the Occupational Safety and Health Administration and local law enforcement. In addition, lawsuits relating to the accident, each of which claims damages in excess of $25,000 were filed in state court in Texas (Harris County District Court) and identified a subsidiary of the Company as one of several defendants. The lawsuits have been settled as to most of the original defendants, with the exception of the subsidiary, and the remaining disputes were removed to federal court in Texas (South ern District) in January 2018. The subsidiary has filed its answer to those complaints, generally denying the allegations and stating certain affirmative defenses, and has separately filed a motion for declaratory judgment in federal court in Texas (Southern District) seeking judgment that it does not owe contractual indemnification obligations to certain of the other original defendants. The Company intends to vigorously defend these suits. Estimating an amount or range of possible losses resulting from litigation proceedings is inherently difficult and requires an extensive degree of judgment, particularly where the matters involve indeterminate claims for monetary damages and are in the stages of the proceedings where key factual and legal issues have not been resolved. Accordingly, the Company is currently unable to predict the ultimate timing or outcome of, or to reasonably estimate the possible loss or a range of possible loss resulting from, these matters. Legal Proceedings Arising in the Ordinary Course of Business The Company is a party, as plaintiff or defendant, to various suits in the ordinary course of business for monetary relief arising principally from personal injuries, wrongful death, collision or other casualty and to claims arising under charter parties and other contract disputes . A substantial majority of such personal injury, wrongful death, collision or other casualty claims against the Company are covered by insurance (subject to deductibles not material in amount). Each of the claims involves an amount which, in the opinion of management, should not be material to the Company’s financial position, results of operations and cash flows. 

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	NOTE 2 1 — SUBSEQUENT EVENTS :  During March 2018, the Company entered into memorandums of agreement and charter party agreements for the sale and lease back of two 2009-built Aframaxes with bareboat charters for periods ranging from 70 to 73 months . Such agreements contain purchase options executable by the Company. The transaction s are expected to close in March 2018 and the Company expects to recognize losses on such sales. 

SUMMARY OF SIGNIFICANT ACCOUN30

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2017
Significant Accounting Policies [Abstract]
Cash and cash equivalents	1. Cash and cash equivalents — Interest-bearing deposits that are highly liquid investments and have a maturity of three months or less when purchased are includ ed in cash and cash equivalents. R estricted cash of $10,579 as of December 31, 201 7 represents legally restricted cash relating to the 2017 Debt Facilities (as defined in Note 8 , “Debt”). Such restricted cash reserves are included in the non-current assets section of the consolidated balance sheet. The 2017 Debt Facilities stipulate that net cash proceeds of any INSW asset sale or casualty event exceeding $5,000, are restricted and required to be reinvested in fixed or capital assets within twelve months of such sale or casualty event or used to repay the principal balance outstanding on the 2017 Debt Facilities. Activity relating to restricted cash is reflected in investing activities in the c onsolidated statements of cash flow.
Concentration of Credit Risk	2. Concentration of Credit Risk — Financial instruments that potentially subject the Company to concentrations of credit risk are voyage receivables due from charterers and pools in which the Company participates. With respect to voyage receivables, the Company limits its credit risk by performing ongoing credit evaluations. Voyage receivables reflected in the consolidated balance sheets as of December 31, 201 7 and 201 6 are net of an allowance for doubtful accounts of $108 and $70 , respectively. The provisions for doubtful accounts for t he years ended December 31, 2017, 2016 and 201 5 were not material. During the thr ee years ended December 31, 2017 , the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted for 89% and 90% of consolidated voyage receivables at December 31, 2017 and 2016 .
Inventories	Inventories —Inventories, which consists principally of fuel, are stated at cost determined on a first-in, first-out basis.
Vessels, vessel lives, deferred drydocking expenditures and other property	4. Vessels, vessel lives, deferred drydocking expenditures and other property —Vessels are recorded at cost and are depreciated to their estimated salvage value on the straight-line basis over the lives of the vessels, which are generally 25 years. Each vessel’s salvage value is equal to the product of its lightweight tonnage and an estimated scrap rate of $300 per ton. Other property, including leasehold improvements, are recorded at cost and amortized on a straight-line basis over the shorter of the terms of the leases or the estimated useful lives of the assets, which range from three to seven years.  Interest costs are capitalized to vessels during the period that vessels are under construction, however, no inte rest was capitalized during 2017 , 201 6 or 201 5 . Expenditures incurred during a drydocking are deferred and amortized on the straight-line basis over the period until the next scheduled drydocking, generally two and a half to five years. The Company only includes in deferred drydocking costs those direct costs that are incurred as part of the drydocking to meet regulatory requirements, or are expenditures that add economic life to the vessel, increase the vessel’s earnings capacity or improve the vessel’s efficiency. Direct costs include shipyard costs as well as the costs of placing the vessel in the shipyard. Expenditures for normal maintenance and repairs, whether incurred as part of the drydocking or not, are expensed as incurred.  The carrying value of each of the Company’s vessels represents its original cost at the time it was delivered or purchased less depreciation calculated using estimated useful lives from the date such vessel was originally delivered from the shipyard. A vessel’s carrying value is reduced to its new cost basis (i.e., its current fair value) if a vessel impairment charge is recorded.
Impairment of long-lived assets	Impairment of long-lived assets —The carrying amounts of long-lived assets held and used by the Company are reviewed for potential impairment whenever events or changes in circumstances indicate that the carrying amount of a particular asset may not be fully recoverable. In such instances, an impairment charge would be recognized if the estimate of the undiscounted future cash flows expected to result from the use of the asset and its eventual disposition is less than the asset’s carrying amount. This assessment is made at the individual vessel level since separately identifiable cash flow information for each vessel is available. The impairment charge, if any, would be measured as the amount by which the carrying amount of a vessel exceeded its fair value. If using an income approach in determining the fair value of a vessel, the Company will consider the discounted cash flows resulting from highest and best use of the vessel asset from a market-participant’s perspective. Alternatively, if using a market approach, the Company will obtain third party appraisals of the estimated fair value of the vessel. A long lived asset impairment charge results in a new cost basis being established for the relevant long lived asset. See Note 5 , “Vessels,” for further discussion on the impairment tests performed on certain of our vessels during the thr ee years ended December 31, 2017 .
Deferred finance charges	6. Deferred finance charges —Finance charges, excluding original issue discounts, incurred in the arrangement and /or amendments resulting in the modification of debt are deferred and amortized to interest expense on either an effective interest method or straight-line basis over the life of the related debt. Unamortized deferred finance charges of $1,691 relating to the INSW Revolver Facility (as defined in Note 8 , “Debt”) are included in other assets in the consolidated balance sheets as of December 31, 2016. Unamortized deferred finance charges of $23,626 relating to the 2017 Term Loan Facility (as defined in Note 8 , “Debt”) and the 2017 Revolver Facility and $19, 827 relating to the INSW Term Loan are included in long-term debt on the consolidated balance sheets as of December 31, 2017 and 2016.  Interest expense relating to the amortization of deferred financing costs amounted to $5,115 in 201 7 , $ 6,449 in 201 6 and $5,625 in 201 5 .
Revenue and expense recognition	7. Revenue and expense recognition —Revenues from time charters and bareboat charters are accounted for as operating leases and are thus recognized ratably over the rental periods of such charters, as service is performed. Voyage revenues and expenses are recognized ratably over the estimated length of each voyage, calculated on a discharge-to-discharge basis and, therefore, are allocated between reporting periods based on the relative transit time in each period. The impact of recognizing voyage expenses ratably over the length of each voyage is not materially different on a quarterly and annual basis from a method of recognizing such costs as incurred. The Company does not begin recognizing voyage revenue until a charter has been agreed to by both the Company and the customer, even if the vessel has discharged its cargo and is sailing to the anticipated load port on its next voyage. Under voyage charters, expenses such as fuel, port charges, canal tolls, cargo handling operations and brokerage commissions are paid by the Company whereas, under time and bareboat charters, such voyage costs are paid by the Company’s customers. For the Company’s vessels operating in pools, revenues and voyage expenses are pooled and allocated to each pool’s participants on a time charter equivalent (“TCE”) basis in accordance with an agreed-upon formula. Such TCE revenues are reported as pool revenues in the accompanying consolidated statement of operations. For the pools in which the Company participates, management monitors, among other things, the relative proportion of the Company’s vessels operating in each of the pools to the total number of vessels in each of the respective pools, and assesses whether or not the Company’s participation interest in each of the pools is sufficiently significant so as to determine that the Company has effective control of the pool.
Derivatives	8. Derivatives —ASC 815, Derivatives and Hedging , requires the Company to recognize all derivatives on the balance sheet at fair value. Derivatives that are not effective hedges must be adjusted to fair value through earnings. If the derivative is an effective hedge, depending on the nature of the hedge, a change in the fair value of the derivative is either recorded to current earnings (fair value hedge), or recognized in other comprehensive income/(loss) and reclassified into earnings in the same period or periods during which the hedge transaction affects earnings (cash flow hedge). The ineffective portion of an effective hedge and the full amount of the change in fair value of derivative instruments that do not qualify for hedge accounting are immediately recognized in earnings. The Company formally documents all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking various hedge transactions. This process includes linking all derivatives that are designated as cash flow hedges to forecasted transactions. The Company also formally assesses (both at the hedge's inception and on an ongoing basis) whether the derivatives that are used in hedging transactions have been highly effective in offsetting changes in the cash flows of hedged items and whether those derivatives may be expected to remain highly effective in future periods. When it is determined that a derivative is not (or has ceased to be) highly effective as a hedge, the Company discontinues hedge accounting prospectively, as discussed below. The Company discontinues hedge accounting prospectively when (1) it determines that the derivative is no longer effective in offsetting changes in the cash flows of a hedged item such as forecasted transactions; (2) the derivative expires or is sold, terminated, or exercised; (3) it is no longer probable that the forecasted transaction will occur; or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate or desired. When the Company discontinues hedge accounting because it is no longer probable that the forecasted transaction will occur in the originally expected period, the gain or loss on the derivative remains in accumulated other comprehensive loss and is reclassified into earnings when the forecasted transaction affects earnings. However, if it is probable that a forecasted transaction will not occur by the end of the originally specified time period or within an additional two-month period of time thereafter, the gains and losses that were accumulated in other comprehensive loss will be recognized immediately in earnings. In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Company will carry the derivative at its fair value on the balance sheet, recognizing changes in the fair value in current-period earnings, unless it is designated in a new hedging relationship. During the three years ended December 31, 201 7 , no ineffectiveness gains or losses were recorded in earnings relative to interest rate caps entered into by the Company or its subsidiaries that qualified for hedge accounting. Any gain or loss realized upon the early termination of an interest rate cap is recognized as an adjustment of interest expense over the shorter of the remaining term of the cap or the hedged debt. See Note 9 , “Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures,” for additional disclosures on the Company’s interest rate caps and other financial instruments.
Income taxes	9. Income taxes — Substantially all of the companies included in the Company’s consolidated financial statements were excluded from the OSG consolidated group for U.S. income tax purposes for the eleven month period ended November 30, 2016 and the year ended December 31, 2015 . T he Company’s financial statements have been prepared on the basis that OSG was responsible for all U.S. taxes for periods prior to December 1, 2016. Prior to December 1, 2016, the Company had not operated as an independent stand-alone entity. However, for the purposes of these consolidated financial statements the Company has calculated income taxes as if it had filed relevant income tax returns on a stand-alone basis. T he Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. Net deferred tax assets are recorded to the extent the Company believes these assets will more likely than not be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies, and results of recent operations. In the event the Company were to determine that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, an adjustment would be made to the deferred tax asset valuation allowance, which would reduce the provision for income taxes in the period such determination is made. Uncertain tax positions are recorded in accordance with ASC 740, Income Taxes, on the basis of a two-step process whereby (1) the Company first determines whether it is more likely than not that the tax positions will be sustained based on the technical merits of the position and (2) for those tax positions that meet the more-likely-than-not recognition threshold, the Company recognizes the largest amount of tax benefit that is greater than 50% likely to be realized upon ultimate settlement with the related tax authority.
Valuation of equity method investments	Valuation of equity method investments — When events and circumstances warrant, investments accounted for under the equity method of accounting are evaluated for impairment. An impairment charge is recorded whenever a decline in fair value of an investment below its carrying amount is determined to be other-than-temporary. Impairment charges related to equity method investments are record ed in equity in i ncome of a ffiliated c ompanies in the accompanying consolidated statements of operations. See Note 6 , “Equity Method Investments,” for further discussion of the Company’s evaluation of impairment of its equity method investments at December 31, 2017 and 2016, respectively.
Use of estimates	Use of estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts of assets, liabilities, equity, revenues and expenses reported in the financial statements and accompanying notes. The most significant estimates relate to the depreciation of vessels and other property, amortization of drydocking costs, estimates used in assessing the recoverability of goodwill, equity method investments, intangible and other long-lived assets, liabilities incurred relating to pension benefits, and income taxes. Actual results could differ from those estimates.
Recently adopted / issued accounting standards	12. Recently Adopted Accounting Standards — In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (ASC 815) , which makes more financial and nonfinancial hedging strategies eligible for hedge accounting, amends the presentation and disclosure requirements, and changes how companies assess effectiveness. It is intended to more closely align hedge accounting with companies’ risk management strategies, simplify the application of hedge accounting, and increase transparency as to the scope and results of hedging programs. The new guidance permits a qualitative effectiveness assessment for certain hedges instead of a quantitative test after initial qualification if the company can reasonably support an expectation of high effectiveness throughout the term of the hedge. An initial quantitative test to establish that the hedge relationship is highly effective is still required. For cash flow hedges, if the hedge is highly effective, all changes in the fair value of the derivative hedging instrument will be recorded in other comprehensive income. They will be reclassified to earnings when the hedged item impacts earnings. On the other hand, for fair value hedges, because the change in fair value of the hedged item and the derivative hedging instrument will still be recorded in current earnings, if the hedge is not 100% effective there will be an income statement impact. The standard will be effective for interim and annual periods beginning after December 31, 2018 and early adoption is permitted. Beginning December 1, 2017, the Company elected to early adopt this accounting standard with an initial application date of January 1, 2017. The adoption of this accounting standard had no impact on the Company’s consolidated financial statements since the hedge relationship that existed at the initial application date had expired prior to the adoption date . Also, the hedge relationship entered into after the December 1, 2017 adoption date had a forward start date of January 1, 2018.  In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting (ASC 718), which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, forfeitures, classification of awards as either equity or liabilities, and classification in the statement of cash flows. The standard is effective for annual periods beginning after December 31, 2016 and interim periods within that reporting period. As a result of the adoption of this accounting standard, effective January 1, 2017, the Company elected to account for forfeitures of share-based payments as they occur. The adoption of this accounting policy had no impact on the Company’s consolidated financial statements since management’s estimate of the forfeiture rate on share-based payment awards granted prior to January 1, 2017 was zero. In addition, the adoption of this accounting standard resulted in the presentation of $349 and $26 of cash paid to the tax authorities for shares withheld to satisfy the Company’s statutory income tax withholding obligations as a financing cash outflow in the consolidated statement of cash flows for the years ended December 31 , 2017 and 2016, respectively.  13. Recently Issued Accounting Standards — In September 2017, the FASB issued ASU 2017-13, Amendments to SEC Paragraphs Pursuant to the Staff Announcement at the July 20, 2017 EITF Meeting and Rescission of Prior SEC Staff Announcements and Observer Comments , which allows certain public business entities (“PBEs”) that otherwise would not meet the definition of a public business entity except for a requirement to include its financial statements or financial information in another entity’s filings with the SEC, to elect to use non-PBE transition dates for the sole purpose of adopting ASU No. 2016-02, Leases (ASC 842), and ASU No. 2014-09, Revenue from Contracts with Customers (ASC 606). Accordingly, all financial statements or financial information of the Company’s FSO and LNG joint ventures that may be included in the Company’s filings with the SEC pursuant to SEC Regulation S-X Rule 4-08(g), Summarized Financial Information of Subsidiaries Not Consolidated and 50 Percent or Less Owned Persons, and/or SEC Regulation S-X Rule 3-09, Separate Financial Statements of Subsidiaries Not Consolidated and 50 Percent or Less Owned Persons, will likely not reflect the adoptions of ASC 606 and ASC 842 until January 1, 2019 and January 1, 2020, respectively.  In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (ASC 7 18), which provides guidance in regards to a change to the terms or conditions of a share-based payment award. An entity is required to account for the effects of a modification unless all the following are met: (1) the fair value of the modified award is the same as the fair value of the original award immediately before the original award is modified; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The guidance is to be applied prospectively to an award modified on or after the adoption date. Management does not expect the adoption of this accounting standard to have a material impact on the Company’s consolidated financial statements.  In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (ASC 715), which requires that an employer classify and report the service cost component in the same line item or items in the statement of operations as other compensation costs arising from services rendered by the pertinent employees during the period and disclose by line item in the statement of operations the amount of net benefit cost that is included in the statement of operations. The other components of net benefit cost would be presented in the statement of operations separately from the service cost component and outside the subtotal of income from operations. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The standard requires application using a retrospective transition method and allows a practical expedient that permits an employer to use the amounts disclosed in its pension and other postretirement benefit plan note for the prior comparative periods as the estimation basis for applying the retrospective presentation requirements . Management does not expect the adoption of this accounting standard to have a material impact on the Company’s consolidated financial statements. Upon adoption, net benefit costs totaling $335 and $985 for the years ended December 31, 2017 and 2016, respectively, that is currently presented in the general and administrative expense line will be presented in the other (expense)/income line on the consolidated statement operations.  In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (ASC 230): Restricted Cash , which requires that amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. The standard will be effective for annual periods beginning after December 31, 2017 and interim periods within that reporting period. T he adoption of this accounting standard will not have a material impact on the Company’s consolidated statements of cash flows.  In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (ASC 230), which amends the guidance in ASC 230 on the classification of certain cash receipts and payments in the statement of cash flows. The primary purpose of the ASU is to reduce the diversity in practice that has resulted from the lack of consistent principles on this topic with respect to (1) debt prepayment or debt extinguishment costs; (2) settlement of zero-coupon debt; (3) contingent consideration payments made after a business combination; (4) proceeds from the settlement of insurance claims; (5) proceeds from the settlement of corporate-owned life insurance policies; (6) distributions received from equity method investees; (7) beneficial interests in securitization transactions; and (8) separately identifiable cash flows and application of the predominance principle. The standard will be effective for interim and annual periods beginning after December 31, 2017 and early adoption is permitted. The guidance requires application using a retrospective transition method. We currently anticipate adopting the standard for classification of distributions received from equity method investees using the cumulative equity earnings approach, which will result in the retrospective reclassification of distributions received from certain affiliated companies accounted for by the equity method, from investing activities to operating activities. Management does not expect the adoption of the other provisions of this accounting standard to have a material impact on the Company’s consolidated financial statements.  In February 2016, the FASB issued ASU No. 2016-02, Leases (ASC 842), which requires lessees to recognize most leases on the balance sheet. This is expected to increase both reported assets and liabilities. The standard will be effective for the first interim reporting period within annual periods beginning after December 15, 2018, although early adoption is permitted. Lessees and lessors will be required to apply the new standard at the beginning of the earliest period presented in the financial statements in which they first apply the new guidance, using a modified retrospective transition method. The requirements of this standard include a significant increase in required disclosures. Management is analyzing the impact of the adoption of this guidance on the Company’s consolidated financial statements, including assessing changes that might be necessary to information technology systems, processes and internal controls to capture new data and address changes in financial reporting. Management expects that the Company will recognize increases in reported amounts for property, plant and equipment and related lease liabilities upon adoption of the new standard. 

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings per Common Share [Abstract]
Components of Calculation of Earnings Per Share	The components of the calculation of basic and diluted earnings per share are as follows:       For the year ended December 31, 2017 2016 2015  Net (loss)/income $ (106,088) $ (18,223) $ 173,170   Weighted average common shares outstanding:  Basic 29,159,440 29,157,992 29,157,387  Diluted 29,159,440 29,157,992 29,157,387  Reconciliations of the numerator of the basic and diluted earnings per share computations are as follows:       For the year ended December 31, 2017 2016 2015  Net (loss)/income allocated to:  Common Stockholders $ (106,088) $ (18,223) $ 173,170  Participating securities - - -  $ (106,088) $ (18,223) $ 173,170 

BUSINESS AND SEGMENT REPORTING

BUSINESS AND SEGMENT REPORTING (Tables)	12 Months Ended
	Dec. 31, 2017
Business and Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Information about the Company’s reportable segments as of and for each of the years in the three-year period ended December 31, 2017 follows:        Crude Product  Tankers Carriers Other Totals  2017  Shipping revenues $ 192,426 $ 97,675 $ - $ 290,101  Time charter equivalent revenues 178,812 96,183 - 274,995  Depreciation and amortization 56,302 22,418 133 78,853  Loss on disposal of vessels and other property, including impairments 85,625 1,230 - 86,855  Adjusted income/(loss) from vessel operations 21,623 (8,385) (31) 13,207  Equity in income of affiliated companies 34,577 - 14,389 48,966  Investments in and advances to affiliated companies at December 31, 2017 260,884 15,612 102,398 378,894  Adjusted total assets at December 31, 2017 1,104,714 382,905 102,025 1,589,644  Expenditures for vessels and vessel improvements 172,164 1,371 - 173,535  Payments for drydockings 17,606 3,790 - 21,396  2016  Shipping revenues $ 271,764 $ 126,555 $ - $ 398,319  Time charter equivalent revenues 258,171 126,314 560 385,045  Depreciation and amortization 52,395 26,696 794 79,885  Loss on disposal of vessels and other property, including impairments 7,585 71,456 162 79,203  Adjusted income from vessel operations 111,768 13,327 710 125,805  Equity in income of affiliated companies 5,584 - 11,265 16,849  Investments in and advances to affiliated companies at December 31, 2016 266,470 15,296 76,915 358,681  Adjusted total assets at December 31, 2016 1,066,184 422,579 76,915 1,565,678  Expenditures for vessels and vessel improvements 691 1,297 - 1,988  Payments for drydockings 7,636 1,622 - 9,258  2015  Shipping revenues $ 324,703 $ 172,931 $ - $ 497,634  Time charter equivalent revenues 304,182 171,608 - 475,790  Depreciation and amortization 51,347 28,763 1,543 81,653  Loss/(gain) on disposal of vessels and other property 31 (3,231) (1,259) (4,459)  Adjusted income/(loss) from vessel operations 157,840 56,746 (1,176) 213,410  Equity in income of affiliated companies 34,371 - 11,188 45,559  Investments in and advances to affiliated companies at December 31, 2015 276,839 13,793 54,259 344,891  Adjusted total assets at December 31, 2015 1,148,361 505,353 43,340 1,697,054  Expenditures for vessels and vessel improvements 91 873 - 964  Payments for drydockings 13,842 6,886 - 20,728 
Reconciliation of Revenue from Segments to Consolidated	Reconciliations of time charter equivalent revenues of the segments to shipping revenues as reported in the consolidated statements of operations follow:      For the year ended December 31, 2017 2016 2015  Time charter equivalent revenues $ 274,995 $ 385,045 $ 475,790  Add: Voyage expenses 15,106 13,274 21,844  Shipping revenues $ 290,101 $ 398,319 $ 497,634  
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	Reconciliations of adjusted income from vessel operations of the segments to (loss)/income before income taxes, as reported in the consolidated statements of operations follow:      For the year ended December 31, 2017 2016 2015  Total adjusted income from vessel operations of all segments $ 13,207 $ 125,805 $ 213,410  General and administrative expenses (24,736) (31,618) (41,516)  Third-party debt modification fees (9,240) - -  Separation and transition costs (604) (9,043) -  Technical management transition costs - - (39)  (Loss)/gain on disposal of vessels and other property,  including impairments (86,855) (79,203) 4,459  Consolidated (loss)/income from vessel operations (108,228) 5,941 176,314  Equity in income of affiliated companies 48,966 16,849 45,559  Other (expense)/income (6,344) (966) 66  Interest expense (40,438) (39,476) (42,970)  Reorganization items, net - (131) (5,659)  (Loss)/income before income taxes $ (106,044) $ (17,783) $ 173,310 
Reconciliation of Assets from Segment to Consolidated	Reconciliations of total assets of the segments to amounts included in the consolidated balance sheets follow:     At December 31, 2017 2016  Total adjusted assets of all segments $ 1,589,644 $ 1,565,678  Corporate unrestricted cash and cash equivalents 60,027 92,001  Corporate restricted cash 10,579 -  Other unallocated amounts 4,234 4,842  Consolidated total assets $ 1,664,484 $ 1,662,521 
Long Lived Assets Deployment by Segment	Certain additional information about the Company’s operations for each of the years in the three year period ended December 31, 2017 follows:      Crude Product  Tankers Carriers Other Consolidated  2017  Total vessels, deferred drydock and other property at December 31, 2017 $ 800,362 $ 339,627 $ 374 $ 1,140,363  2016  Total vessels, deferred drydock and other property at December 31, 2016 $ 753,028 $ 377,095 $ 484 $ 1,130,607  2015  Total vessels, deferred drydock and other property at December 31, 2015 $ 804,514 $ 472,675 $ 297 $ 1,277,486 

VESSELS, DEFERRED DRYDOCK AND33

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Schedule of Property	Vessels and other property , excluding vessel held for sale, consist of the following:     As of 2017 2016  Vessels, at cost $ 1,404,360 $ 1,478,940  Accumulated depreciation (302,087) (381,449)  Vessels, net 1,102,273 1,097,491   Other property, at cost 7,377 8,680  Accumulated depreciation and amortization (4,923) (6,121)  Other property, net 2,454 2,559   Total Vessels and other property $ 1,104,727 $ 1,100,050 
Schedule of Property Plant and Equipment by Segment	All except one of the Company’s vessels are pledged as collateral under the INSW Facilities (see Note 8, “Debt”). The aggregate carrying value of the 42 vessels pledged as collateral under the INSW Facilities at December 31, 2017, including a 2002-built MR which was held for sale as of December 31, 2017, was $1,102,844 . A breakdown of the carrying value of the Company’s vessels by reportable segment and fleet as of December 31, 2017 and 2016 follows:      As of December 31, 2017  Net Average Number of  Accumulated Carrying Vessel Age Owned  Cost Depreciation Value (by dwt) Vessels   Crude Tankers  VLCC (includes ULCC) $ 663,880 $ (209,966) $ 453,914 12.5 10  Suezmax 117,259 (1,821) 115,438 0.4 2  Aframax 167,146 (21,064) 146,082 12.6 7  Panamax 61,120 (538) 60,582 15.3 8  Total Crude Tankers 1,009,405 (233,389) 776,016 (1) 12.1 27   Product Carriers  LR2 73,681 (9,305) 64,376 3.4 1  LR1 106,176 (13,122) 93,054 9.0 4  MR 215,098 (46,271) 168,827 11.5 10  Total Product Carriers 394,955 (68,698) 326,257 (2) 9.6 15   Fleet Total $ 1,404,360 $ (302,087) $ 1,102,273 11.7 42  (1) Includes seven VLCCs, two Suezmaxes, and three Aframaxes with an aggregate carrying value of $581,461 , which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $459,000 by $122,461 . (2) Includes one LR2, four LR1s and four MRs with an aggregate carrying value of $281,383 , which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $209,375 , by $72,008 .      As of December 31, 2016  Net Average Number of  Accumulated Carrying Vessel Age Owned  Cost Depreciation Value (by dwt) Vessels   Crude Tankers  VLCC (includes ULCC) $ 681,891 $ (235,159) $ 446,732 12.1 9  Aframax 247,863 (66,943) 180,920 11.6 7  Panamax 121,810 (18,506) 103,304 14.3 8  Total Crude Tankers 1,051,564 (320,608) 730,956 12.3 24   Product Carriers  LR2 73,681 (6,601) 67,080 2.4 1  LR1 106,176 (8,474) 97,702 8.1 4  MR 247,519 (45,766) 201,753 11.2 13  Total Product Carriers 427,376 (60,841) 366,535 9.3 18   Fleet Total $ 1,478,940 $ (381,449) $ 1,097,491 11.7 42 
Vessel/Fleet [Member]
Property, Plant and Equipment [Line Items]
Schedule of Property Plant and Equipment by Segment	 Vessel activity for the three years ended December 31, 2017 is summarized as follows:      Accumulated Net Book  Vessel Cost Depreciation Value  Balance at January 1, 2015 $ 1,648,115 (341,575) $ 1,306,540  Purchases and vessel additions 1,531 -  Disposals (6,755) 1,003  Depreciation - (64,385)  Balance at December 31, 2015 1,642,891 (404,957) 1,237,934  Purchases and vessel additions 2,127 -  Disposals - (63,328)  Depreciation (166,078) 86,836  Balance at December 31, 2016 1,478,940 (381,449) 1,097,491  Purchases and vessel additions 174,108 -  Disposals and transfer to held for sale (23,266) 2,232  Depreciation - (59,883)  Impairment (225,422) 137,013  Balance at December 31, 2017 $ 1,404,360 $ (302,087) $ 1,102,273 
Drydock [Member]
Property, Plant and Equipment [Line Items]
Schedule of Property	Drydocking activity for the three years ended December 31, 2017 is summarized as follows:     2017 2016 2015  Balance at January 1 $ 30,557 $ 37,075 $ 29,325  Additions 19,205 8,822 22,981  Sub-total 49,762 45,897 52,306  Drydock amortization (18,367) (15,340) (15,231)  Amount charged to loss/gain on sale of vessels (867) - -  Balance at December 31 $ 30,528 $ 30,557 $ 37,075 

EQUITY METHOD INVESTMENTS (Tabl

EQUITY METHOD INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments [Abstract]
Schedule of Equity Method Investments	Financial information for the equity method investees that were significant for the three years ended December 31, 2017, adjusted for basis and accounting policy differences, is as follows:       For the year ended December 31, 2017 2016 2015  Shipping revenues $ 234,916 $ 247,451 $ 245,444  Ship operating expenses (106,228) (114,487) (113,639)  Income from vessel operations 128,688 132,964 131,805  Other income 3,497 830 2,357  Interest expense (36,831) (43,038) (47,218)  Income tax provision (1,886) - -  Net income $ 93,468 $ 90,756 $ 86,944   Percentage of ownership in equity investees 49.9% - 50.0 % 49.9% - 50.0% 49.9% - 50.0%  Equity in income/(loss) of affiliated companies, before  consolidating and reconciling adjustments $ 46,704 $ 45,355 $ 43,449   Impairment of equity method investments in FSO Joint Venture - (30,475) -  Amortization on deferred gain on 2009 sale  of TI Africa to FSO Joint Venture 2,301 2,409 2,409  Amortization of interest capitalized during construction of  LNG vessels (419) (419) (419)  Other 380 (21) 120  Equity in income/(loss) of affiliated companies $ 48,966 $ 16,849 $ 45,559 
Equity Method Investments Summarized Balance Sheet Information	   As of December 31, 2017 2016  Current assets $ 77,545 $ 128,531  Vessels, net 1,344,613 1,386,836  Other assets 65,551 66,708  Total assets $ 1,487,709 $ 1,582,075   Current liabilities $ 78,273 $ 150,153  Long-term debt and other non-current liabilities 917,564 1,055,922  Equity 491,872 376,000  Total liabilities and equity $ 1,487,709 $ 1,582,075   Percentage of ownership in equity investees 49.9% - 50.0% 49.9% - 50.0%  INSW Share of affiliate's equity, before consolidating and reconciling adjustments $ 245,751 $ 187,868   Impairment of equity method investments in FSO Joint Venture (30,475) (30,475)  Advances from shareholders of FSO Joint Venture (2) 162,762 203,513  Unamortized deferred gain on 2009 sale of TI Africa to FSO Joint Venture, net (34,284) (36,585)  Unamortized interest capitalized during construction of LNG vessels 10,275 10,693  Other (1) 24,865 23,667  Investments in and advances to affiliated companies $ 378,894 $ 358,681  (1) Primarily relates to working capital deposits that the Company maintains with the commercial pools in which it participates. (2) Such advances are unsecured, interest free and not repayable within one year . See Note

VARIABLE INTEREST ENTITIES ("35

VARIABLE INTEREST ENTITIES ("VIEs") (Tables)	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities ("VIEs") [Abstract]
Schedule of Variable Interest Entities	The following table presents the carrying amounts of assets and liabilities in the consolidated balance sheets related to the VIEs described above as of December 31, 2017 and 2016:      Consolidated Balance Sheet as of December 31, 2017 2016  Investments in Affiliated Companies $ 255,456 $ 261,403 
Schedule of Variable Interest Entities Liability in Condensed Consolidated Balance Sheet to Maximum Exposure to Loss	The table below compares the Company’s liability in the consolidated balance sheet to the maximum exposure to loss at December 31, 2017:         Consolidated Balance Sheet Maximum Exposure to Loss  Other Liabilities $ - $ 255,456 

DEBT (Tables)

DEBT (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Applicable Margins and Floor Interest Rates Exit Financing Facility	    Facility 2017 Term Loan Facility 2017 Revolver Facility  Rate ABR LIBOR ABR LIBOR  Floor 2.00% 1.00% 2.00% 1.00%  Applicable Margin 4.50% 5.50% 2.50% 3.50% 
Contractual Obligation, Fiscal Year Maturity Schedule	   Year Amount  2018 $ 24,063  2019 27,500  2020 27,500  2021 27,500  2022 440,000  Aggregate principal payments required $ 546,563 
Schedule of Interest Paid	The following table summarizes interest expense, including amortization of issuance and deferred financing costs (for additional information related to deferred financing costs see Note 2, “Significant Accounting Policies”), commitment, administrative and other fees, recognized during the years ended December 31, 2017, 2016 and 2015 with respect to the Company’s debt facilities:      Debt facility 2017 2016 2015  2017 Term Loan Facility, due 2022 $ 22,546 $ - $ -  2017 Revolver Facility, due 2021 495 - -  INSW Facilities, due 2019 16,743 38,442 42,688  Total debt related interest expense $ 39,784 $ 38,442 $ 42,688    The following table summarizes interest paid, excluding deferred financing fees paid, and capitalized interest, during the years ended December 31, 2017, 2016 and 2015 with respect to the Company’s debt facilities:      Debt facility 2017 2016 2015  2017 Term Loan Facility, due 2022 $ 16,319 $ - $ -  2017 Revolver Facility, due 2021 316 - -  INSW Facilities, due 2019 16,732 33,039 36,368  Total debt related interest expense paid $ 33,367 $ 33,039 $ 36,368 
Term Loan [Member]
Schedule of Long-term Debt Instruments	Debt consists of the following:     December 31, December 31,  2017 2016  2017 Term Loan Facility, due 2022, net of unamortized discount  and deferred costs of $23,074 $ 523,489 $ -  2017 Revolver Facility, net of unamortized deferred costs of $552 29,448 -  INSW Term Loan Facility, due 2019, net of unamortized discount  and deferred costs of $20,311 - 439,651  552,937 439,651  Less current portion (24,063) (6,183)  Long-term portion $ 528,874 $ 433,468   Capitalized terms used hereafter have the meaning given in these consolidated financial statements or in the respective transaction documents referred to below, including subsequent amendments thereto.

FAIR VALUE OF FINANCIAL INSTR37

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The estimated fair values of the Company’s financial instruments, other than derivatives that are not measured at fair value on a recurring basis, categorized based upon the fair value hierarchy, at December 31, 2017 and 2016, are as follows:      Fair Value Level 1 Level 2  December 31, 2017:  Cash and cash equivalents (1) $ 70,606 $ 70,606 $ -  2017 Term Loan Facility (550,689) - (550,689)  2017 Revolver Facility (30,227) (30,227)   December 31, 2016:  Cash and cash equivalents $ 92,001 $ 92,001 $ -  INSW Term Loan (447,888) - (447,888)  (1) Includes non-current restricted cash of $10,579 at December 31, 2017. 
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following tables present information with respect to the fair values of derivatives reflected in the December 31, 2017 and 2016 balance sheets on a gross basis by transaction: Fair Values of Derivative Instruments:     Asset Derivatives Liability Derivatives  Balance Sheet Balance Sheet  Location Amount Location Amount  December 31, 2017:  Derivatives designated as hedging instruments:  Interest rate caps:  Current portion Prepaid expenses and other current assets $ 16 Accounts payable, accrued expenses and other current liabilities $ -  Long-term portion Other assets 886 Other liabilities -  Total derivatives designated as hedging instruments $ 902 $ -   December 31, 2016:  Derivatives designated as hedging instruments:  Interest rate caps:  Long-term portion Other assets $ - Other liabilities $ -  Total derivatives designated as hedging instruments $ - $ - 
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The effect of cash flow hedging relationships recognized in other comprehensive income/(loss) excluding amounts reclassified from accumulated other comprehensive loss (effective portion), including hedges of equity method investees, for the years ended December 31, 2017, 2016 and 2015 follows:     For the year ended December 31, 2017 2016 2015  Interest rate swaps $ (1,132) $ (3,050) $ (9,721)  Interest rate caps (8) (2) (472)  Total $ (1,140) $ (3,052) $ (10,193)  The effect of cash flow hedging relationships on the consolidated statements of operations is presented excluding hedges of equity method investees. The effect of the Company’s cash flow hedging relationships on the consolidated statement of operations for the years ended December 31, 2017, 2016 and 2015 is shown below:      Statement of Operations  Effective Portion of Gain/(Loss)  Reclassified from Accumulated  Other Comprehensive Loss Ineffective Portion  Amount of Amount of  Location Gain/(Loss) Location Gain/(Loss)  For the year ended December 31, 2017:  Interest rate caps Interest expense $ (131) Interest expense $ -  Total $ (131) $ -   For the year ended December 31, 2016:  Interest rate caps Interest expense $ (517) Interest expense $ -  Total $ (517) $ -   For the year ended December 31, 2015:  Interest rate caps Interest expense $ (2) Interest expense $ -  Total $ (2) $ - 
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table presents the fair values, which are pre-tax, for assets and liabilities measured on a recurring basis (excluding investments in affiliated companies):     Fair Value Level 2  Assets/(Liabilities) at December 31, 2017  Derivative Assets (interest rate caps) $ 902 $ 902 (1)   Assets/(Liabilities) at December 31, 2016  Derivative Assets (interest rate caps) $ - $ - (1) (1) For the interest rate cap, fair value is derived using valuation models that utilize the income valuation approach. These valuation models take into account contract terms such as maturity, as well as other inputs such as interest rate yield curves and creditworthiness of the counterparty and the Company.
Fair Value Measurements, Nonrecurring	The following table summarizes the fair values of assets for which an impairment charge was recognized for the year ended December 31, 201 7 :      Impairment  Description Fair Value Level 2 Level 3 Charges  Crude Tankers - Vessels held and used (1) (2) $ 147,584 $ 78,479 $ 69,105 $ (85,626)  Product Carriers - Vessels held and used (1) (2) $ 22,400 $ 22,400 $ - $ (2,782)  (1) Aggregate pre-tax impairment charges of $7,346 related to one vessel in the Crude Tanker segment and two vessels in the Product Carriers segment and $81,062 related to twelve vessels in the International Crude Tanker segment were recorded during the three-month periods ended September 30, 2017 and December 31, 2017, respectively. (2) The fair value measurements aggregating $67,979 at December 31, 2017 used to determine impairment for four vessels and fair value measurements aggregating $32,900 at September 30, 2017 used to determine impairment for three vessels were based upon a market approach, which considered the expected sales prices or scrap values of vessels obtained from vessel appraisals. Because sales of vessels occur somewhat infrequently the expected sales prices are considered to be Level 2. Fair value measurements aggregating $69,105 at December 31, 2017 used to determine the impairment for eight vessels were based on the income approach, which utilized cash flow projections consistent with the most recent projections of the Company and a discount rate equivalent to INSW's weighted average cost of capital. Because the Company uses its own cash flow projections, the cash flow projections are considered to be Level 3.

ACCOUNTS PAYABLE, ACCRUED EXP38

ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2017
ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES [Abstract]
Schedule of Accounts Payable, Accrued Expenses and Other Current Liabilities	   At December 31, 2017 2016  Accounts payable $ 330 $ 2,866  Payroll and benefits 5,897 5,672  Interest 3,437 4,042  Due to owners on chartered in vessels 867 856  Accrued drydock, repairs and vessel betterment costs 1,838 1,608  Bunkers and lubricants 1,893 2,787  Charter revenues received in advance 918 6,725  Insurance 575 2,650  Accrued vessel expenses 3,369 6,804  Accrued general and administrative expenses 1,599 2,644  Other 2,082 1,583  Total accounts payable, accrued expense and other current liabilities $ 22,805 $ 38,237 

TAXES (Tables)

TAXES (Tables)	12 Months Ended
	Dec. 31, 2017
Taxes [Abstract]
Components of Income Tax (Provisions) and Benefits	The components of the income tax provisions follow:      For the year ended December 31, 2017 2016 2015  Current $ 44 $ 440 $ 140  Deferred - - -  Total provision for income taxes $ 44 $ 440 $ 140 
Reconcilation of Effective to Statutory Tax Rate	The differences between income taxes expected at the Marshall Islands statutory income tax rate of zero percent and the reported income tax provisions are summarized as follows:      For the year ended December 31, 2017 2016 2015  Marshall Islands statutory income tax rate - % - % - %  Change in valuation allowance 0.78 % 25.29 % - %  Liquidation of subsidiaries (0.88) % (29.53) % - %  Income subject to tax in other jurisdictions 0.06 % 1.76 % 0.08 %  Effective income tax rate (0.04) % (2.48) % 0.08 % 
Components of Deferred Tax Liabilities and Assets	The significant components of the Company’s deferred tax liabilities and assets follow:      As of December 31, 2017 2016  Deferred tax assets:  Net operating loss carryforwards $ 1,178 $ 1,711  Excess of tax over book basis of depreciable assets 548 548  Pensions 2,852 3,147  Total deferred tax assets 4,578 5,406  Less: Valuation allowance (4,578) (5,406)  Deferred tax assets, net - -  Net noncurrent deferred tax assets/(liabilities) $ - $ - 
Reconcilation of Amounts of Unrecognized Tax Benefits	The following is tabular rollforward of the Company’s unrecognized tax benefits (excluding interest and penalties):      2017 2016  Balance of unrecognized tax benefits as of January 1, $ 153 $ 40  Increases for positions taken in prior years - 115  Decreases for positions taken in prior years - -  Changes due to currency translations - (2)  Balance of unrecognized tax benefits as of December 31, $ 153 $ 153 

RELATED PARTIES (Tables)

RELATED PARTIES (Tables)	12 Months Ended
	Dec. 31, 2017
RELATED PARTIES [Abstract]
Schedule of Related Party Transactions	The following tables show certain related party transactions between INSW and OSG:     For the year ended December 31, 2017 2016 2015  Corporate overhead allocations from OSG  General and administrative $ - $ 21,486 $ 36,792  Depreciation - 517 730  Separation and transition costs - 6,569 -  Reorganization items, net - 131 5,659  Total corporate overhead allocations from OSG $ - $ 28,703 $ 43,181 

CAPITAL STOCK AND STOCK COMPE41

CAPITAL STOCK AND STOCK COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2017
Capital Stock and Stock Compensation [Abstract]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	Activity with respect to restricted common stock and restricted stock units under INSW compensation plans is summarized as follows:      Activity for the three years ended December 31, 2017 Common Stock   Nonvested Shares Outstanding at December 31, 2015 -  RSUs issued to replace OSG RSUs 110,294  Granted 32,067  Vested ( $19.04 per share) (1) (25,103)  Nonvested Shares Outstanding at December 31, 2016 117,258  Granted 165,503  Vested ( $18.21 - $19.13 per share) (1) (108,584)  Nonvested Shares Outstanding at December 31, 2017 174,177 (1) Includes 6,508 (2016) and 12,442 (2017) shares of common stock forfeited by employees to cover withholding taxes.  Activity with respect to stock options under INSW compensation plans is summarized as follows:
Schedule of Share-based Compensation, Stock Options, Activity	    Activity for the three years ended December 31, 2017 Common Stock   Options Outstanding at December 31, 2015 -  Options issued to replace OSG options 127,559  Exercised -  Options Outstanding at December 31, 2016 127,559  Granted 148,271  Exercised -  Options Outstanding at December 31, 2017 275,830  Options Exercisable at December 31, 2017 95,618 

ACCUMULATED OTHER COMPREHENSI42

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Loss [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss, net of related taxes, in the consolidated balance sheets follow:      At December 31, 2017 2016  Unrealized losses on derivative instruments $ (28,989) $ (40,317)  Items not yet recognized as a component of net periodic benefit cost (pension plans) (11,418) (11,950)  $ (40,407) $ (52,267)  The following tables present the changes in the balances of each component of accumulated other comprehensive loss, net of related taxes, for the three years ended December 31, 2017.     Unrealized losses on cash flow hedges Items not yet recognized as a component of net periodic benefit cost (pension plans) Foreign currency translation adjustment Total   Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (1,140) 17 - (1,123)  Amounts reclassified from accumulated other  comprehensive loss 12,468 515 - 12,983  Total change in accumulated other comprehensive loss 11,328 532 - 11,860  Balance at December 31, 2017 $ (28,989) $ (11,418) $ - $ (40,407)   Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (3,052) (2,364) 42 (5,374)  Amounts reclassified from accumulated other  comprehensive loss 16,181 1,050 - 17,231  Total change in accumulated other comprehensive loss 13,129 (1,314) 42 11,857  Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)   Balance at December 31, 2014 $ (61,356) $ (12,988) $ (29) $ (74,373)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (10,193) 1,870 (13) (8,336)  Amounts reclassified from accumulated other  comprehensive loss 18,103 482 - 18,585  Total change in accumulated other comprehensive loss 7,910 2,352 (13) 10,249  Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124) 
Reclassification Out of Accumulated Other Comprehensive Income (Loss)	   Unrealized losses on cash flow hedges Items not yet recognized as a component of net periodic benefit cost (pension plans) Foreign currency translation adjustment Total   Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (1,140) 17 - (1,123)  Amounts reclassified from accumulated other  comprehensive loss 12,468 515 - 12,983  Total change in accumulated other comprehensive loss 11,328 532 - 11,860  Balance at December 31, 2017 $ (28,989) $ (11,418) $ - $ (40,407)   Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (3,052) (2,364) 42 (5,374)  Amounts reclassified from accumulated other  comprehensive loss 16,181 1,050 - 17,231  Total change in accumulated other comprehensive loss 13,129 (1,314) 42 11,857  Balance at December 31, 2016 $ (40,317) $ (11,950) $ - $ (52,267)   Balance at December 31, 2014 $ (61,356) $ (12,988) $ (29) $ (74,373)  Current period change, excluding amounts reclassified from  accumulated other comprehensive loss (10,193) 1,870 (13) (8,336)  Amounts reclassified from accumulated other  comprehensive loss 18,103 482 - 18,585  Total change in accumulated other comprehensive loss 7,910 2,352 (13) 10,249  Balance at December 31, 2015 $ (53,446) $ (10,636) $ (42) $ (64,124)  The following table presents information with respect to amounts reclassified out of accumulated other comprehensive loss for the three years ended December 31, 2017.    Years Ended December 31,  Accumulated Other Comprehensive Loss Component 2017 2016 2015 Statement of Operations Line Item   Unrealized losses on cash flow hedges:  Interest rate swaps entered into by the Company's Equity in income of  equity method joint venture investees $ (12,337) $ (15,664) $ (18,101) affiliated companies   Interest rate caps entered into by the Company's  subsidiaries (131) (517) (2) Interest expense   Items not yet recognized as a component of net  periodic benefit cost (pension plans):  Net periodic benefit costs associated with  pension and postretirement benefit plans for General and  shore-based employees (515) (1,050) (482) administrative expenses  $ (12,983) $ (17,231) $ (18,585) Total before and net of tax

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2017
Bareboat Charters-In [Member]
Lease [Abstract]
Operating Leases of Lessee Disclosure	The future minimum commitments and related number of operating days under these operating leases are as follows:      Bareboat Charters-in:   At December 31, 2017 Amount Operating Days  2018 $ 1,841 279  Net minimum lease payments $ 1,841 279 
Charters-Out [Member]
Lease [Abstract]
Operating Leases of Lessee Disclosure	The future minimum revenues, before reduction for brokerage commissions, expected to be received on noncancelable time charters and the related revenue days (revenue days represent calendar days, less days that vessels are not available for employment due to repairs, drydock or lay-up) are as follows:      At December 31, 2017 Amount Revenue Days  2018 $ 6,218 604  Future minimum revenues $ 6,218 604 
Property Subject to Operating Lease [Member] | Time Charters-In [Member]
Lease [Abstract]
Schedule of Property Subject to or Available for Operating Lease	Time Charters-in:      At December 31, 2017 Amount Operating Days  2018 $ 11,849 1,218  Net minimum lease payments $ 11,849 1,218 
Property Subject to Operating Lease [Member] | Office Space [Member]
Lease [Abstract]
Schedule of Property Subject to or Available for Operating Lease	The future minimum commitments under all lease obligations for office space are as follows:      At December 31, Amount  2018 $ 1,249  2019 1,166  2020 1,152  2021 665  Net minimum lease payments $ 4,232 

PENSION AND OTHER POSTRETIREM44

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Tables)	12 Months Ended
	Dec. 31, 2017
Pension and Other Postretirement Benefit Plans [Abstract]
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	Information with respect to the Scheme for which INSW uses a December 31 measurement date, is as follows:      Pension Benefits  At December 31, 2017 2016  Change in benefit obligation:  Benefit obligation at beginning of year $ 29,240 $ 29,899  Interest cost on benefit obligation 797 932  Actuarial losses/(gains) (519) 5,525  Benefits paid (770) (603)  Settlements - (1,579)  Foreign exchange losses/(gains) 2,779 (4,934)  Benefit obligation at year end 31,527 29,240   Change in plan assets:  Fair value of plan assets at beginning of year 25,466 21,090  Actual return on plan assets 1,714 2,503  Employer contributions 787 7,605  Benefits paid (770) (603)  Settlements - (1,775)  Plan administration costs (64) -  Foreign exchange (gains)/losses 2,394 (3,354)  Fair value of plan assets at year end 29,527 25,466  Unfunded status at December 31 $ (2,000) $ (3,774) 
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Information for the defined benefit pension plan with accumulated benefit obligations in excess of plan assets follows:      At December 31, 2017 2016  Projected benefit obligation $ 31,527 $ 29,240  Accumulated benefit obligation 31,527 29,240  Fair value of plan assets 29,527 25,466 
Schedule of Net Benefit Costs	   Pension benefits  For the year ended December 31, 2017 2016 2015  Components of expense:  Plan administration costs $ 64 $ - $ -  Interest cost on benefit obligation 797 886 1,164  Expected return on plan assets (1,041) (951) (1,159)  Amortization of prior-service costs 68 67 79  Recognized net actuarial loss 447 343 403  Recognized settlement loss - 640 -  Net periodic benefit cost $ 335 $ 985 $ 487 
Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates	The weighted-average assumptions used to determine benefit obligations follow:     Pension benefits  At December 31, 2017 2016  Discount rate 2.40% 2.60% 
Schedule of Assumptions Used	The weighted-average assumptions used to determine net periodic benefit costs follow:       Pension benefits  For the year ended December 31, 2017 2016 2015  Discount rate 2.60% 3.80% 3.55%  Expected (long-term) return on plan assets 3.85% 5.62% 5.35%  Rate of future compensation increases - - - 
Schedule of Expected Benefit Payments	Expected benefit payments are as follows:       Pension benefits  2018 $ 667  2019 700  2020 735  2021 772  2022 810  Years 2023-2027 4,703  $ 8,387 
Schedule of Changes in Fair Value of Plan Assets	The fair values of the Company’s pension plan assets at December 31, 2017, by asset category are as follows:      Description Fair Value Level 1 Level 2 (1)  Cash and cash equivalents $ 971 $ 971 $ -  Managed fund 28,556 - 28,556  Total $ 29,527 $ 971 $ 28,556   (1) Quoted prices for the managed fund is not available from an active market source since such investments are pooled investment funds. The unitized pooled investment vehicles have been valued at the latest available bid price or single price provided by the pooled investment manager. Shares in other pooled arrangements have been valued at the latest available net asset value, determined in accordance with fair value principles, provided by the pooled investment manager.

OTHER INCOME_(EXPENSE) (Tables)

OTHER INCOME/(EXPENSE) (Tables)	12 Months Ended
	Dec. 31, 2017
OTHER INCOME/(EXPENSE) [Abstract]
Schedule of Other Nonoperating Income (Expense)	   For the year ended December 31, 2017 2016 2015  Investment income:  Interest $ 676 $ 376 $ 66  676 376 66  Write-off of deferred financing costs (7,020) (5,097) -  Discount on repurchase of debt - 3,755 -  $ (6,344) $ (966) $ 66 

REORGANIZATION ITEMS, NET (Tabl

REORGANIZATION ITEMS, NET (Tables)	12 Months Ended
	Dec. 31, 2017
Chapter 11 Filing Going Concern and Other Related Matters [Abstract]
Schedule of Reorganization Items Net	On November 14, 2012 (the “Petition Date”), OSG and 180 of its subsidiaries including INSW Debtor entities, filed voluntary petitions for reorganization under Chapter 11 of the U.S. Code (the “Bankruptcy Code”) in the U.S. Bankruptcy Court for the District of Delaware (the “Bankruptcy Court”). The Debtors filed with the Bankruptcy Court a plan of reorganization which was subsequently confirmed by the Bankruptcy Court’s order entered on July 18, 2014. On August 5, 2014 (the “Effective Date”), the plan of reorganization became effective and OSG and its affiliated debtors, including INSW Debtor entities, emerged from bankruptcy. On February 10, 2017, pursuant to a final decree and order of the Bankruptcy Court, OSG’s one remaining case, as the parent company, was closed.  Reorganization items, net represent amounts incurred subsequent to the bankruptcy date as a direct result of the filing of the Chapter 11 cases. The table below reflects the recovery of previously allocated professional fees associated with a litigation matter that OSG subsequently settled for an amount in excess of its related out-of-pocket expenses.     For the year ended December 31, 2017 2016 2015  Allocated trustee fees $ - $ 74 $ 147  Allocated professional fees - (3,220) 5,422  Other claim adjustments - 3,277 90  $ - $ 131 $ 5,659 

2017 AND 2016 QUARTERLY RESUL47

2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS (Table)	12 Months Ended
	Dec. 31, 2017
2017 AND 2016 QUARTERLY RESULTS OF OPERATIONS [Abstract]
Schedule of Quarterly Financial Information	     Selected Financial Data for the Quarter Ended March 31, June 30, Sept. 30, Dec. 31,  2017  Shipping revenues $ 88,750 $ 71,957 $ 59,968 $ 69,426  Loss on disposal of vessels and other property, including impairments - - (5,406) (81,449)  Income/(loss) from vessel operations 13,344 (9,645) (23,749) (88,178)  Interest expense (8,965) (9,076) (11,030) (11,367)  Income tax benefit/(provision) (4) (4) (23) (13)  Net income/(loss) 18,067 (11,619) (21,816) (90,720)   Basic and Diluted net income/(loss) per share $ 0.62 $ (0.40) $ (0.75) $ (3.12)     Selected Financial Data for the Quarter Ended March 31, June 30, Sept. 30, Dec. 31,  2016  Shipping revenues $ 128,676 $ 103,062 $ 80,771 $ 85,810  Gain/(loss) on disposal of vessels and other property, including impairments 171 - (49,640) (29,734)  Income/(loss) from vessel operations 53,129 29,079 (47,758) (28,509)  Interest expense (10,742) (9,690) (9,519) (9,525)  Reorganization items, net 4,471 (520) (3,849) (233)  Income tax benefit/(provision) (4) (173) 20 (283)  Net income/(loss) 59,890 30,506 (50,862) (57,757)   Basic and Diluted net income/(loss) per share $ 2.05 $ 1.05 $ (1.74) $ (1.98) 

DESCRIPTION OF BUSINESS AND B48

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Narrative) (Details)	12 Months Ended
	Dec. 31, 2016shares	Dec. 31, 2017propertyshares
Schedule of Equity Method Investments [Line Items]
Common stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares authorized		10,000,000
Shares received pursuant to spinoff	0.3333
Number of vessels in fleet | property		55
Number of vessels owned (including joint ventures) | property		49
Warrant [Member]
Schedule of Equity Method Investments [Line Items]
Shares received pursuant to spinoff	0.063327

SUMMARY OF SIGNIFICANT ACCOUN49

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)$ / item	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts receivable	$ 108,000	$ 70,000
Amortization of financing costs	5,115,000	6,449,000	$ 5,625,000
Accounting Standards Update 2017-07 [Member]
Summary Of Significant Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results	$ 335,000	$ 985,000
Accounts Receivable [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk, percentage	89.00%	90.00%
INSW Revolver Facility [Member] | INSW Facilities [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross		$ 1,691,000
Term Loan [Member] | INSW Facilities [Member]
Summary Of Significant Accounting Policies [Line Items]
Deferred finance costs, gross	$ 23,626,000	19,827,000
Vessel/Fleet [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	25 years
Property, plant and equipment salvage, value per ton | $ / item	300
Interest costs capitalized	$ 0	$ 0	$ 0
Other Property [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Other Property [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	7 years
Drydock [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period for deferred costs	2 years 6 months
Drydock [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization period for deferred costs	5 years

EARNINGS PER COMMON SHARE (Narr

EARNINGS PER COMMON SHARE (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	397,833	11,153
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	105,429
Participaing securities allocated a portion of income		1,489
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	275,830
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Participaing securities allocated a portion of income	35,876		0

EARNINGS PER COMMON SHARE (Calc

EARNINGS PER COMMON SHARE (Calculation of EPS) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings per Common Share [Abstract]
Common Stockholders									$ (106,088)	$ (18,223)	$ 173,170
Net (Loss)/Income	$ (90,720)	$ (21,816)	$ (11,619)	$ 18,067	$ (57,757)	$ (50,862)	$ 30,506	$ 59,890	$ (106,088)	$ (18,223)	$ 173,170
Weighted average common shares outstanding:
Basic									29,159,440	29,157,992	29,157,387
Diluted									29,159,440	29,157,992	29,157,387
Common stock - basic and diluted									29,159,440	29,157,992	29,157,387

BUSINESS AND SEGMENT REPORTIN52

BUSINESS AND SEGMENT REPORTING (Reportable Segments Information) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment									2
Shipping revenues	$ 69,426	$ 59,968	$ 71,957	$ 88,750	$ 85,810	$ 80,771	$ 103,062	$ 128,676	$ 290,101	$ 398,319	$ 497,634
Time charter equivalent revenues									274,995	385,045	475,790
Depreciation and amortization									78,853	79,885	81,653
Loss/(gain) on disposal of vessels and other property, including impairments	81,449	$ 5,406			29,734	$ 49,640		$ (171)	86,855	79,203	(4,459)
Income/(loss) from vessel operations									13,207	125,805	213,410
Equity in income of affiliated companies									48,966	16,849	45,559
Investments in and advances to affiliated companies	378,894				358,681				378,894	358,681	344,891
Adjusted total assets	1,589,644				1,565,678				1,589,644	1,565,678	1,697,054
Total assets	1,664,484				1,662,521				1,664,484	1,662,521
Expenditures for vessels									173,535	1,988	964
Payments for drydockings									21,396	9,258	20,728
International Crude Tankers Segment [Member]
Segment Reporting Information [Line Items]
Shipping revenues									192,426	271,764	324,703
Time charter equivalent revenues									178,812	258,171	304,182
Depreciation and amortization									56,302	52,395	51,347
Loss/(gain) on disposal of vessels and other property, including impairments									85,625	7,585	31
Income/(loss) from vessel operations									21,623	111,768	157,840
Equity in income of affiliated companies									34,577	5,584	34,371
Investments in and advances to affiliated companies	260,884				266,470				260,884	266,470	276,839
Adjusted total assets	1,104,714				1,066,184				1,104,714	1,066,184	1,148,361
Expenditures for vessels									172,164	691	91
Payments for drydockings									17,606	7,636	13,842
International Product Carriers Segment [Member]
Segment Reporting Information [Line Items]
Shipping revenues									97,675	126,555	172,931
Time charter equivalent revenues									96,183	126,314	171,608
Depreciation and amortization									22,418	26,696	28,763
Loss/(gain) on disposal of vessels and other property, including impairments									1,230	71,456	(3,231)
Income/(loss) from vessel operations									(8,385)	13,327	56,746
Investments in and advances to affiliated companies	15,612				15,296				15,612	15,296	13,793
Adjusted total assets	382,905				422,579				382,905	422,579	505,353
Expenditures for vessels									1,371	1,297	873
Payments for drydockings									3,790	1,622	6,886
Other Segments [Member]
Segment Reporting Information [Line Items]
Time charter equivalent revenues										560
Depreciation and amortization									133	794	1,543
Loss/(gain) on disposal of vessels and other property, including impairments										162	(1,259)
Income/(loss) from vessel operations									(31)	710	(1,176)
Equity in income of affiliated companies									14,389	11,265	11,188
Investments in and advances to affiliated companies	102,398				76,915				102,398	76,915	54,259
Adjusted total assets	$ 102,025				$ 76,915				$ 102,025	$ 76,915	$ 43,340

BUSINESS AND SEGMENT REPORTIN53

BUSINESS AND SEGMENT REPORTING (Reconciliation of Time Charter Revenue to Shipping Revenues) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business and Segment Reporting [Abstract]
Time charter equivalent revenues									$ 274,995	$ 385,045	$ 475,790
Add: Voyage expenses									15,106	13,274	21,844
Shipping revenues	$ 69,426	$ 59,968	$ 71,957	$ 88,750	$ 85,810	$ 80,771	$ 103,062	$ 128,676	$ 290,101	$ 398,319	$ 497,634

BUSINESS AND SEGMENT REPORTIN54

BUSINESS AND SEGMENT REPORTING (Reconciliation of Income from Vessel Operations to Loss Before Reorganization) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Total income (loss) from vessel operations of all segments									$ 13,207	$ 125,805	$ 213,410
General and administrative expenses									(24,736)	(31,618)	(41,516)
Third-party debt modification costs									9,240
Separation and transition costs									(604)	(9,043)
Technical management transition costs											(39)
(Loss)/gain on disposal of vessels and other property, including impairments	$ (81,449)	$ (5,406)			$ (29,734)	$ (49,640)		$ 171	(86,855)	(79,203)	4,459
Consolidated income/(loss) from vessel operations	(88,178)	(23,749)	$ (9,645)	$ 13,344	(28,509)	(47,758)	$ 29,079	53,129	(108,228)	5,941	176,314
Equity in income of affiliated companies									48,966	16,849	45,559
Other expense									(6,344)	(966)	66
Interest expense	$ (11,367)	$ (11,030)	$ (9,076)	$ (8,965)	(9,525)	(9,519)	(9,690)	(10,742)	(40,438)	(39,476)	(42,970)
Reorganization items, net					$ (233)	$ (3,849)	$ (520)	$ 4,471		(131)	(5,659)
Income/(Loss) before Income Taxes									(106,044)	(17,783)	173,310
Vessel Operations [Member]
Total income (loss) from vessel operations of all segments									13,207	125,805	213,410
General and administrative expenses									(24,736)	(31,618)	(41,516)
Third-party debt modification costs									9,240
Separation and transition costs									(604)	(9,043)
Technical management transition costs											(39)
(Loss)/gain on disposal of vessels and other property, including impairments									(86,855)	(79,203)	4,459
Consolidated income/(loss) from vessel operations									(108,228)	5,941	176,314
Equity in income of affiliated companies									48,966	16,849	45,559
Other expense									(6,344)	(966)	66
Interest expense									(40,438)	(39,476)	(42,970)
Reorganization items, net										(131)	(5,659)
Income/(Loss) before Income Taxes									$ (106,044)	$ (17,783)	$ 173,310

BUSINESS AND SEGMENT REPORTIN55

BUSINESS AND SEGMENT REPORTING (Reconcilation of Assets of Segments to Consolidated Amounts) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Adjusted total assets	$ 1,589,644	$ 1,565,678	$ 1,697,054
Cash and cash equivalents	60,027	92,001	308,858	$ 178,240
Total assets	1,664,484	1,662,521
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Restricted cash	10,579
Unrestricted cash	60,027	92,001
Other Segments [Member]
Segment Reporting Information [Line Items]
Adjusted total assets	102,025	76,915	$ 43,340
Other unallocated amounts	4,234	4,842
Operating Segments [Member]
Segment Reporting Information [Line Items]
Adjusted total assets	$ 1,589,644	$ 1,565,678

BUSINESS AND SEGMENT REPORTIN56

BUSINESS AND SEGMENT REPORTING (Additional Information) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Vessels Deferred Dry Dock and Other Property	$ 1,140,363	$ 1,130,607	$ 1,277,486
International Crude Tankers Segment [Member]
Segment Reporting Information [Line Items]
Vessels Deferred Dry Dock and Other Property	800,362	753,028	804,514
International Product Carriers Segment [Member]
Segment Reporting Information [Line Items]
Vessels Deferred Dry Dock and Other Property	339,627	377,095	472,675
Other Segments [Member]
Segment Reporting Information [Line Items]
Vessels Deferred Dry Dock and Other Property	$ 374	$ 484	$ 297

VESSELS, DEFERRED DRYDOCK AND57

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Nov. 30, 2017	Jul. 31, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use			$ 7,346		$ 88,408	$ 79,242
Payments to acquire equipment	$ 53,000	$ 116,000			173,535	1,988	$ 964
Gain (loss) on disposition of property					1,553	39	4,459
Vessel/Fleet [Member]
Property, Plant and Equipment [Line Items]
Debt instrument, collateral amount					434,000
2001-built MR and a 2004-built MR [Member]
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition of property					1,594
2 Long Range (LRs), 1 Aframax and 1 Panamax [Member]
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use				$ 49,640
One Medium Range Vessel [Member]
Property, Plant and Equipment [Line Items]
Gain (loss) on disposition of property							$ 3,236
1 Panamax and 7 MRs Vessels [Member]
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use						$ 29,602
Twelve vessels (one ULCC, one VLCC, four Aframaxes and six Panamaxes) [Member]
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets held-for-use					81,062
INSW Facilities [Member]
Property, Plant and Equipment [Line Items]
Debt instrument, collateral amount					$ 1,102,844

VESSELS, DEFERRED DRYDOCK AND58

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Vessels and Other Property) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Net Carrying Value	$ 1,104,727	$ 1,100,050
Vessel/Fleet and Other Property [Member]
Property, Plant and Equipment [Line Items]
Net Carrying Value	1,104,727	1,100,050
Vessel/Fleet [Member]
Property, Plant and Equipment [Line Items]
Cost	1,404,360	1,478,940	$ 1,642,891	$ 1,648,115
Accumulated Depreciation	(302,087)	(381,449)	(404,957)	(341,575)
Net Carrying Value	1,102,273	1,097,491	$ 1,237,934	$ 1,306,540
Other Property [Member]
Property, Plant and Equipment [Line Items]
Cost	7,377	8,680
Accumulated Depreciation	(4,923)	(6,121)
Net Carrying Value	$ 2,454	$ 2,559

VESSELS, DEFERRED DRYDOCK AND59

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Breakdown of Vessel Carrying Value) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)item		Dec. 31, 2016USD ($)item	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Property, Plant and Equipment [Line Items]
Net Carrying Value	$ 1,104,727		$ 1,100,050
Vessel/Fleet [Member]
Property, Plant and Equipment [Line Items]
Cost	1,404,360		1,478,940	$ 1,642,891	$ 1,648,115
Accumulated Depreciation	(302,087)		(381,449)	(404,957)	(341,575)
Net Carrying Value	$ 1,102,273		$ 1,097,491	$ 1,237,934	$ 1,306,540
Average Vessel Age	11 years 8 months 12 days		11 years 8 months 12 days
Number of owned vessels | item	42		42
International Crude Tankers Segment [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 1,009,405		$ 1,051,564
Accumulated Depreciation	(233,389)		(320,608)
Net Carrying Value	$ 776,016	[1]	$ 730,956
Average Vessel Age	12 years 1 month 6 days		12 years 3 months 18 days
Number of owned vessels | item	27		24
International Crude Tankers Segment [Member] | VLCCs (included ULCC) [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 663,880		$ 681,891
Accumulated Depreciation	(209,966)		(235,159)
Net Carrying Value	$ 453,914		$ 446,732
Average Vessel Age	12 years 1 month 6 days		12 years 1 month 6 days
Number of owned vessels | item	10		9
International Crude Tankers Segment [Member] | Aframaxes (LR2) [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 167,146		$ 247,863
Accumulated Depreciation	(21,064)		(66,943)
Net Carrying Value	$ 146,082		$ 180,920
Average Vessel Age	12 years 7 months 6 days		11 years 7 months 6 days
Number of owned vessels | item	7		7
International Crude Tankers Segment [Member] | Suzemax [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 117,259
Accumulated Depreciation	(1,821)
Net Carrying Value	$ 115,438
Average Vessel Age	4 months 24 days
Number of owned vessels | item	2
International Crude Tankers Segment [Member] | Panamaxes (LR1) [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 61,120		$ 121,810
Accumulated Depreciation	(538)		(18,506)
Net Carrying Value	$ 60,582		$ 103,304
Average Vessel Age	15 years 3 months 18 days		14 years 3 months 18 days
Number of owned vessels | item	8		8
International Crude Tankers Segment [Member] | 1 Ultra Large Crude Carriers (ULCC), 8 Very Large Crude Carriers (VLCC), 7 Aframaxes and 7 Panamaxes [Member]
Property, Plant and Equipment [Line Items]
Net Carrying Value	$ 581,461
Property, plant and equipment, fair value	459,000
Pledged collateral market value over carrying value difference	122,461
International Product Carriers Segment [Member]
Property, Plant and Equipment [Line Items]
Cost	394,955		$ 427,376
Accumulated Depreciation	(68,698)		(60,841)
Net Carrying Value	$ 326,257	[2]	$ 366,535
Average Vessel Age	9 years 7 months 6 days		9 years 3 months 18 days
Number of owned vessels | item	15		18
International Product Carriers Segment [Member] | Aframaxes (LR2) [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 73,681		$ 73,681
Accumulated Depreciation	(9,305)		(6,601)
Net Carrying Value	$ 64,376		$ 67,080
Average Vessel Age	3 years 4 months 24 days		2 years 4 months 24 days
Number of owned vessels | item	1		1
International Product Carriers Segment [Member] | Panamaxes (LR1) [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 106,176		$ 106,176
Accumulated Depreciation	(13,122)		(8,474)
Net Carrying Value	$ 93,054		$ 97,702
Average Vessel Age	9 years		8 years 1 month 6 days
Number of owned vessels | item	4		4
International Product Carriers Segment [Member] | MR Vessel [Member]
Property, Plant and Equipment [Line Items]
Cost	$ 215,098		$ 247,519
Accumulated Depreciation	(46,271)		(45,766)
Net Carrying Value	$ 168,827		$ 201,753
Average Vessel Age	11 years 6 months		11 years 2 months 12 days
Number of owned vessels | item	10		13
International Product Carriers Segment [Member] | 1 LR2, 4 LR1s and 5 MRs Vessels [Member]
Property, Plant and Equipment [Line Items]
Net Carrying Value	$ 281,383
Property, plant and equipment, fair value	209,375
Pledged collateral market value over carrying value difference	$ 72,008
[1]	Includes seven VLCCs, two Suezmaxes, and three Aframaxes with an aggregate carrying value of $581,461, which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $459,000 by $122,461.
[2]	Includes one LR2, four LR1s and four MRs with an aggregate carrying value of $281,383, which the Company believes exceeds their aggregate market values (estimated by taking an average of two third party vessel appraisals) of approximately $209,375, by $72,008.

VESSELS, DEFERRED DRYDOCK AND60

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Vessel Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Book Value
Beginning Balance	$ 1,100,050
Ending Balance	1,104,727	$ 1,100,050
Vessel/Fleet [Member]
Vessel Cost
Beginning Balance	1,478,940	1,642,891	$ 1,648,115
Purchases and vessel additions	174,108	2,127	1,531
Transfers from construction in progress		166,078
Disposals	(23,266)		(6,755)
Impairment	(225,422)
Ending Balance	1,404,360	1,478,940	1,642,891
Accumulated Depreciation
Beginning Balance	(381,449)	(404,957)	(341,575)
Disposals	2,232	(63,328)	1,003
Depreciation	(59,883)	86,836	(64,385)
Impairment	137,013
Ending Balance	(302,087)	(381,449)	(404,957)
Net Book Value
Beginning Balance	1,097,491	1,237,934	1,306,540
Ending Balance	$ 1,102,273	$ 1,097,491	$ 1,237,934

VESSELS, DEFERRED DRYDOCK AND61

VESSELS, DEFERRED DRYDOCK AND OTHER PROPERTY (Drydocking Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Vessels, Deferred Drydock and Other Property [Abstract]
Beginning Balance	$ 30,557	$ 37,075	$ 29,325
Additions	19,205	8,822	22,981
Sub-total	49,762	45,897	52,306
Drydock amortization	(18,367)	(15,340)	(15,231)
Amount charged to loss/gain on sale of vessels	(867)
Ending Balance	$ 30,528	$ 30,557	$ 37,075

EQUITY METHOD INVESTMENTS (Narr

EQUITY METHOD INVESTMENTS (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Nov. 30, 2004m³	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Notional amount of interest rate cash flow hedge derivatives		$ 300,000	$ 400,000
Investments in and advances to affiliated companies		378,894	358,681
Long-term debt		552,937	439,651
Income (loss) from equity method investments		48,966	16,849	$ 45,559
Other than temporary impairment - Equity method investment, Impairment Charges		30,475	30,475
FSO Asia and FSO Africa [Member]
Schedule of Equity Method Investments [Line Items]
Other than temporary impairment - Equity method investment, Impairment Charges			$ 30,475
Liquid Natural Gas Carrier Vessel [Member]
Schedule of Equity Method Investments [Line Items]
Line of credit facility, amount outstanding		$ 597,129
Minimum [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		49.90%	49.90%	49.90%
Maximum [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%	50.00%	50.00%
Euronav Nv / FSO Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Investments in and advances to affiliated companies		$ 251,594
Other than temporary impairment - Equity method investment, Impairment Charges			$ 30,475
Fair Value Inputs, Discount Rate			9.50%
Euronav Nv / FSO Joint Venture [Member] | Interest Rate Swap [Member]
Schedule of Equity Method Investments [Line Items]
Derivative, fixed interest rate		3.90%
Euronav Nv / FSO Joint Venture [Member] | FSO Asia and FSO Africa [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		50.00%
Interest rate cash flow hedge liability at fair value		$ 2,236
Euronav Nv / FSO Joint Venture [Member] | FSO Asia and FSO Africa [Member] | Interest Rate Swap [Member]
Schedule of Equity Method Investments [Line Items]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss		111
Euronav Nv / FSO Joint Venture [Member] | Liquid Natural Gas Carrier Vessel [Member] | Interest Rate Swap [Member]
Schedule of Equity Method Investments [Line Items]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss		28,980
LNG Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Investments in and advances to affiliated companies		102,398
LNG Joint Venture [Member] | Liquid Natural Gas Carrier Vessel [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	49.90%
Line of credit facility, amount outstanding			$ 638,827
Storage volume, per carrier | m³	216,200
Initial term of contract	25 years
LNG Joint Venture [Member] | Liquid Natural Gas Carrier Vessel [Member] | Interest Rate Swap [Member]
Schedule of Equity Method Investments [Line Items]
Notional amount of interest rate cash flow hedge derivatives		576,429	$ 617,636
Derivative, fixed interest rate			4.90%	4.90%
Interest rate cash flow hedge liability at fair value		58,243	$ 80,458
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss			40,076
Other Investees [Member]
Schedule of Equity Method Investments [Line Items]
Investments in and advances to affiliated companies		$ 24,902
Term Loan [Member] | Euronav Nv / FSO Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Long-term debt			$ 75,343

EQUITY METHOD INVESTMENTS (Equi

EQUITY METHOD INVESTMENTS (Equity Method Investments Income Schedule) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 30, 2004
Shipping revenues	$ 234,916	$ 247,451	$ 245,444
Ship operating expenses	(106,228)	(114,487)	(113,639)
Income from vessel operations	128,688	132,964	131,805
Other income	3,497	830	2,357
Interest expense	(36,831)	(43,038)	(47,218)
Income tax provision	(1,886)
Net income	93,468	90,756	86,944
Equity in net income of affiliated companies, before consolidating and reconciling adjustments	46,704	45,355	43,449
Impairment of equity method investments	(30,475)	(30,475)
Other income/(expense)	380	(21)	120
Equity in income/(loss) of affiliated companies	$ 48,966	$ 16,849	$ 45,559
Minimum [Member]
Equity method investment, ownership percentage	49.90%	49.90%	49.90%
Maximum [Member]
Equity method investment, ownership percentage	50.00%	50.00%	50.00%
FSO Asia and FSO Africa [Member]
Impairment of equity method investments		$ (30,475)
FSO Africa [Member]
Amortization on deferred gain on 2009 sale of TI Africa to FSO Joint Venture	$ 2,301	2,409	$ 2,409
Euronav Nv / FSO Joint Venture [Member]
Impairment of equity method investments		(30,475)
Euronav Nv / FSO Joint Venture [Member] | FSO Asia and FSO Africa [Member]
Equity method investment, ownership percentage	50.00%
LNG Joint Venture [Member]
Amortization of interest capitalized during vessel construction	$ (419)	$ (419)	$ (419)
LNG Joint Venture [Member] | Liquid Natural Gas Carrier Vessel [Member]
Equity method investment, ownership percentage				49.90%

EQUITY METHOD INVESTMENTS (Eq64

EQUITY METHOD INVESTMENTS (Equity Method Investments Balance Sheet Schedule) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Nov. 30, 2004
Equity Method Investment, Summarized Financial Information, Current Assets	$ 77,545	$ 128,531
Vessels less accumulated depreciation	1,344,613	1,386,836
Other assets	65,551	66,708
Total assets	1,487,709	1,582,075
Equity Method Investment, Summarized Financial Information, Current Liabilities	78,273	150,153
Total Liabilities	917,564	1,055,922
Equity	491,872	376,000
Total liabilities and equity	1,487,709	1,582,075
INSW Share of affiliate's equity, before consolidating and reconciling adjustments	245,751	187,868
Impairment of equity method investments	(30,475)	(30,475)
Advances from shareholders	162,762	203,513
Unamortized deferred gain on 2009 sale of TI Africa to FSO Africa, net	(34,284)	(36,585)
Unamortized interest capitalized during vessel construction	10,275	10,693
Other	24,865	23,667
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total	378,894	358,681
FSO Asia and FSO Africa [Member]
Impairment of equity method investments		(30,475)
Euronav Nv / FSO Joint Venture [Member]
Impairment of equity method investments		$ (30,475)
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total	$ 251,594
Euronav Nv / FSO Joint Venture [Member] | FSO Asia and FSO Africa [Member]
Equity method investment, ownership percentage	50.00%
LNG Joint Venture [Member]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total	$ 102,398
LNG Joint Venture [Member] | Liquid Natural Gas Carrier Vessel [Member]
Equity method investment, ownership percentage			49.90%

VARIABLE INTEREST ENTITIES ("65

VARIABLE INTEREST ENTITIES ("VIEs") (Narrative) (Details) $ in Thousands	Dec. 31, 2017USD ($)item	Dec. 31, 2016USD ($)
Variable Interest Entity [Line Items]
Number of joint ventures | item	3
Accounts receivable, net, current	$ 58,187	$ 66,918
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Accounts receivable, net, current	$ 12,617

VARIABLE INTEREST ENTITIES ("66

VARIABLE INTEREST ENTITIES ("VIEs") (Schedule of Variable Interest Entities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Investments in Affiliated Companies	$ 378,894	$ 358,681	$ 344,891
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Investments in Affiliated Companies	$ 255,456	$ 261,403

VARIABLE INTEREST ENTITIES ("67

VARIABLE INTEREST ENTITIES ("VIEs") (Schedule of Variable Interest Entities Liability in Condensed Consolidated Balance Sheet to Maximum Exposure to Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Other Liabilities	$ 2,721	$ 4,438
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Maximum Exposure to Loss	$ 255,456

DEBT (Financing Facilities) (Na

DEBT (Financing Facilities) (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Nov. 30, 2017	Jul. 31, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
INSW Facilities [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 628,375
Line of credit facility, maximum borrowing capacity						50,000
Debt instrument, basis spread on variable rate					2.00%
Repayments of debt			$ 458,416
Debt instrument, collateral amount					$ 1,102,844
INSW Facilities [Member] | 1-Month London Interbank Offered Rate LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate					1.00%
INSW Facilities [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate					0.50%
Term Loan Facility, due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount					$ 500,000
Debt instrument, Accordion Feature		$ 50,000			$ 50,000
Debt instrument, amortization, quarterly percentage of original principal amount					0.625%
Debt instrument, additional mandatory prepayments, percentage					50.00%
Debt instrument, maximum amount of cash dividend					$ 15,000
Debt instrument, collateral amount					$ 300,000
Debt Instrument, Covenant, Fair Market Value of Collateral, Percentage					41.00%
Term Loan Facility, due 2022 [Member] | Scenario, Plan [Member]
Debt Instrument [Line Items]
Debt instrument, additional mandatory prepayments, percentage				1.25%
Revolver Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity						$ 50,000
Proceeds from Issuance of Debt	$ 30,000	$ 50,000
Maximum [Member] | Term Loan Facility, due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant, Fair Market Value of Collateral, Percentage					65.00%

DEBT (Debt Modifications, Repur

DEBT (Debt Modifications, Repurchases and Extinguishments) (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Loss on repurchase of debt		$ (3,755)
Write off of deferred debt issuance cost	$ (7,020)	(5,097)
INSW Facilities [Member]
Debt Instrument [Line Items]
Write off of deferred debt issuance cost		$ 5,097
Payments of financing costs	$ 8,273

DEBT (Schedule of Long-term Deb

DEBT (Schedule of Long-term Debt Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Long-term debt	$ 552,937	$ 439,651
Less current portion	(24,063)	(6,183)
Long-term portion	528,874	433,468
Term Loan Facility, due 2022 [Member]
Long-term debt	523,489
Revolver Facility [Member]
Long-term debt	29,448
Term Loan [Member] | INSW Facilities [Member]
Long-term debt	$ 546,563
Term Loan [Member] | INSW Facilities, due 2019 [Member]
Long-term debt		$ 439,651

DEBT (Schedule of Applicable Ma

DEBT (Schedule of Applicable Margins and Floor Interest Rates Exit Financing Facility) (Details) - INSW Facilities [Member]	12 Months Ended
	Dec. 31, 2017
Debt instrument, basis spread on variable rate	2.00%
INSW Revolver Facility [Member] | Base Rate [Member] | Floor [Member]
Debt instrument, basis spread on variable rate	2.00%
INSW Revolver Facility [Member] | Base Rate [Member] | Applicable Margin [Member]
Debt instrument, basis spread on variable rate	2.50%
INSW Revolver Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Floor [Member]
Debt instrument, basis spread on variable rate	1.00%
INSW Revolver Facility [Member] | London Interbank Offered Rate (LIBOR) [Member] | Applicable Margin [Member]
Debt instrument, basis spread on variable rate	3.50%
Term Loan [Member] | Base Rate [Member] | Floor [Member]
Debt instrument, basis spread on variable rate	2.00%
Term Loan [Member] | Base Rate [Member] | Applicable Margin [Member]
Debt instrument, basis spread on variable rate	4.50%
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Floor [Member]
Debt instrument, basis spread on variable rate	1.00%
Term Loan [Member] | London Interbank Offered Rate (LIBOR) [Member] | Applicable Margin [Member]
Debt instrument, basis spread on variable rate	5.50%

DEBT (Contractual Obligation, F

DEBT (Contractual Obligation, Fiscal Year Maturity Schedule Table 1) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Shedule Of Long Term Debt Maturities Repayments Of Principal [Line Items]
Long-term Debt	$ 552,937	$ 439,651
Term Loan [Member] | INSW Facilities [Member]
Shedule Of Long Term Debt Maturities Repayments Of Principal [Line Items]
2,018	24,063
2,019	27,500
2,020	27,500
2,021	27,500
2,022	440,000
Long-term Debt	$ 546,563

DEBT (Contractual Obligation,73

DEBT (Contractual Obligation, Fiscal Year Maturity Schedule Table 2) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reorganization expense	$ 233	$ 3,849	$ 520	$ (4,471)		$ 131	$ 5,659
Repayments of secured debt					$ 458,416	65,167
Write off of deferred debt issuance cost					(7,020)	(5,097)
Debt Facilities 2017 [Member]
Payments of debt issuance costs					24,307
Deferred finance costs, gross					15,067
Write off of deferred debt issuance cost					9,240
Gain (Loss) on Extinguishment of Debt, before Write off of Debt Issuance Cost					7,020
INSW Facilities [Member]
Contractual interest (including default interest)					39,784	38,442	42,688
Line of credit facility, maximum borrowing capacity	50,000					50,000
Debt instrument, face amount	628,375					628,375
Interest Paid					33,367	33,039	36,368
Write off of deferred debt issuance cost						5,097
Gain (Loss) on Extinguishment of Debt, before Write off of Debt Issuance Cost						3,755
Gain (Loss) on Extinguishment of Debt						(1,342)
Debt Issuance Costs, Legal and Consulting Fees						225
INSW Facilities, due 2019 [Member]
Contractual interest (including default interest)					16,743	38,442	42,688
Repayments of secured debt						83,832
Interest Paid					16,732	33,039	36,368
Debt instrument, repurchased face amount	68,922					68,922
Term Loan Facility, due 2022 [Member]
Contractual interest (including default interest)					22,546
Debt instrument, face amount					500,000
Interest Paid					16,319
Revolver Facility [Member]
Contractual interest (including default interest)					495
Line of credit facility, maximum borrowing capacity	50,000					50,000
Interest Paid					316
INSW Revolver Facility [Member] | INSW Facilities [Member]
Deferred finance costs, gross	1,691					1,691
OSG Inc. [Member]
Reorganization expense					131	131	$ 5,659
Term Loan [Member] | INSW Facilities [Member]
Deferred finance costs, gross	$ 19,827				$ 23,626	$ 19,827

FAIR VALUE OF FINANCIAL INSTR74

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures [Abstract]
Derivative, notional amount	$ 300,000	$ 400,000
Derivative, cap interest rate	2.50%

FAIR VALUE OF FINANCIAL INSTR75

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Value of Financial Instruments Other Than Derivatives) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 70,606	$ 92,001
Restricted cash	10,579
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	70,606	92,001
Term Loan [Member] | INSW Facilities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(550,689)	(447,888)
Term Loan [Member] | INSW Facilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(550,689)	$ (447,888)
Line of Credit [Member] | INSW Facilities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	(30,227)
Line of Credit [Member] | INSW Facilities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Payable, Fair Value Disclosure	$ (30,227)

FAIR VALUE OF FINANCIAL INSTR76

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Value of Derivative Instruments) (Details) - Interest Rate Cap [Member] - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivative Asset	$ 902
Derivative Liability
Prepaid Expenses and Other Current Assets [Member]
Derivative Asset, Current	16
Other Assets [Member]
Derivative Asset, Noncurrent	886
Accounts Payable and Accrued Liabilities [Member]
Derivative Liability, Current
Other Liabilities [Member]
Derivative Liability, Noncurrent

FAIR VALUE OF FINANCIAL INSTR77

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Effect of Cash Flow Hedging Relationships) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Unrealized losses on derivative instruments	$ (1,140)	$ (3,052)	$ (10,193)
Interest Rate Cap [Member]
Unrealized losses on derivative instruments	(8)	(2)	(472)
Interest Rate Swap [Member]
Unrealized losses on derivative instruments	$ (1,132)	$ (3,050)	$ (9,721)

FAIR VALUE OF FINANCIAL INSTR78

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Effect of Cash Flow Hedging Relationships on Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Ineffective Portion
Interest Rate Cap [Member] | Interest Expense [Member]
Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss	(131)	$ (517)	$ (2)
Ineffective Portion

FAIR VALUE OF FINANCIAL INSTR79

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Values of Assets and Liabilities Measured on Recurring Basis) (Details) - Interest Rate Cap [Member] - Fair Value, Measurements, Recurring [Member] $ in Thousands	Dec. 31, 2017USD ($)
Derivative assets	$ 902
Fair Value, Inputs, Level 2 [Member]
Derivative assets	$ 902	[1]
[1]	For the interest rate cap, fair value is derived using valuation models that utilize the income valuation approach. These valuation models take into account contract terms such as maturity, as well as other inputs such as interest rate yield curves and creditworthiness of the counterparty and the Company.

FAIR VALUE OF FINANCIAL INSTR80

FAIR VALUE OF FINANCIAL INSTRUMENTS, DERIVATIVES AND FAIR VALUE DISCLOSURES (Fair Value of Items Measured on Nonrecurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of equity method investments			$ (30,475)	$ (30,475)
International Crude Tankers Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	$ 147,584		147,584
Vessels held for use, Impairment Charges			(85,626)
International Crude Tankers Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	78,479		78,479
International Crude Tankers Segment [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	69,105		69,105
International Product Carriers Segment [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	22,400		22,400
Vessels held for use, Impairment Charges			(2,782)
International Product Carriers Segment [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	22,400		22,400
one vessel in the Crude Tanker segment and two vessels in the Product Carriers segment [member] | International Crude and Product Carriers Segments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	32,900		32,900
Impairment of equity method investments		$ 7,346
twelve vessels in the International Crude Tanker segment [member] | International Crude and Product Carriers Segments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Vessels held for use, Fair Value	67,979		$ 67,979
Impairment of equity method investments	$ 81,062

ACCOUNTS PAYABLE, ACCRUED EXP81

ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Schedule of Accounts Payable, Accrued Expenses and Other Current Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
ACCOUNTS PAYABLE, ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES [Abstract]
Accounts payable	$ 330	$ 2,866
Payroll and benefits	5,897	5,672
Interest	3,437	4,042
Due to owners on chartered in vessels	867	856
Accrued drydock and repair costs	1,838	1,608
Bunkers and lubricants	1,893	2,787
Charter revenues received in advance	918	6,725
Insurance	575	2,650
Accrued vessel expenses	3,369	6,804
Accrued general and administrative expenses	1,599	2,644
Other	2,082	1,583
Total accounts payable, accrued expense and other current liabilities	$ 22,805	$ 38,237

TAXES (Narrative) (Details)

TAXES (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Taxes [Abstract]
Percent of shipping income subject to U.S. federal taxation	4.00%
Operating loss carryforwards	$ 6,931	$ 42,001
Indefinite-lived net operating loss carryforwards	6,931
Operating loss carryforwards, valuation allowance	4,578	5,406
Increase (decrease) in valuation allowance	(828)
Unrecognized tax benefits, interest on income taxes accrued	51	$ 33
Unrecognized tax benefits, decrease resulting from settlements with taxing authorities	$ 94

TAXES (Components of Income Tax

TAXES (Components of Income Tax (Provisions) and Benefits) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Taxes [Abstract]
Current									$ 44	$ 440	$ 140
Total provision for income taxes	$ 13	$ 23	$ 4	$ 4	$ 283	$ (20)	$ 173	$ 4	$ 44	$ 440	$ 140

TAXES (Reconcilation of Effecti

TAXES (Reconcilation of Effective to Statutory Tax Rate) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adjustments due to:
Liquidation of subsidiaries	(0.88%)	(29.53%)
MARSHALL ISLANDS [Member]
Adjustments due to:
Change in valuation allowance	0.78%	25.29%
Income subject to tax in other jurisdictions	0.06%	1.76%	0.08%
Effective tax rate	(0.04%)	(2.48%)	0.08%

TAXES (Components of Deferred T

TAXES (Components of Deferred Tax Liabilities and Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 1,178	$ 1,711
Excess of tax over book basis of depreciable assets	548	548
Pensions	2,852	3,147
Total deferred tax assets	4,578	5,406
Less: Valuation allowance	(4,578)	(5,406)
Net deferred tax assets
Net noncurrent deferred tax assets

TAXES (Reconcilation of Amounts

TAXES (Reconcilation of Amounts of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Taxes [Abstract]
Balance of unrecognized tax benefits as of January 1,	$ 153	$ 40
Increases for positions taken in prior years		115
Decreases for positions taken in prior years
Changes due to currency translations		(2)
Balance of unrecognized tax benefits as of December 31,	$ 153	$ 153

RELATED PARTIES (Narrative) (De

RELATED PARTIES (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended					12 Months Ended
	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018	Dec. 31, 2014
Reorganization Items, net			$ 233	$ 3,849	$ 520	$ (4,471)		$ 131	$ 5,659
Non-cash expense relating to stock compensation benefits							$ 3,808	2,841	2,811
Net Carrying Value			1,100,050				1,104,727	1,100,050
Impairment of long-lived assets held-for-use		$ 7,346					88,408	79,242
Separation and transition costs							604	9,043
Severance costs related to separation and transition costs								3,337
Cash dividends paid to parent company by unconsolidated subsidiaries							$ 202,000	$ 200,000
Dividends paid, per share							$ 6.93	$ 6.86
Income Recognized							$ 64
Transition Services Agreement [Member]
Accounts receivable, related parties, current			27				63	$ 27
Accounts payable, related parties, current			31				731	31
Vessel/Fleet [Member]
Net Carrying Value			1,097,491				1,102,273	1,097,491	1,237,934		$ 1,306,540
OSG Inc. [Member]
Capital contribution from former parent							3,797	9,424
Reorganization Items, net							131	131	$ 5,659
Non-cash expense relating to stock compensation benefits							2,520	2,811
Allocated general and administrative expenses recorded as capital contributions							1,146	954
Accounts payable, related parties, current			$ 683				367	$ 683
Qatar Gas Transport Company Limited Nakilat Joint Venture [Member]
Guarantor obligation fee							100
INSW Facilities [Member]
Repayments of debt	$ 458,416
LNG Joint Venture [Member]
Annual fee to related party							$ 125
LNG Joint Venture [Member] | Scenario, Forecast [Member]
Annual fee to related party										$ 135

RELATED PARTIES (Schedule of Re

RELATED PARTIES (Schedule of Related Party Transactions) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reorganization Items, net	$ 233	$ 3,849	$ 520	$ (4,471)		$ 131	$ 5,659
OSG Inc. [Member]
General and administrative						21,486	36,792
Depreciation						517	730
Severance and relocation costs						6,569
Reorganization Items, net					$ 131	131	5,659
Total corporate overhead allocations from the Former Parent						$ 28,703	$ 43,181

CAPITAL STOCK AND STOCK COMPE89

CAPITAL STOCK AND STOCK COMPENSATION (Narrative) (Details)	1 Months Ended	3 Months Ended				12 Months Ended
	Jan. 31, 2018$ / sharesshares	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reorganization Items, net | $		$ 233,000	$ 3,849,000	$ 520,000	$ (4,471,000)		$ 131,000	$ 5,659,000
Restricted stock or unit expense | $						$ 2,982,000	$ 2,157,000	2,380,000
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term						8 years 9 months 4 days	7 years 11 months 16 days
Stock options, compensation expense (income) | $						$ 826,000	$ 684,000	$ 431,000
Share based compensation expense, unrecognized | $						$ 3,066,000
Share based compensation expense, unrecognized, period						1 year 7 months 21 days
Share-based Compensation Arrangement by Share-based Payment Award, Shares Purchased for Award						13,961
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased | $ / shares						$ 18.66
Stock Repurchased and Retired During Period, Shares						160,000
Stock Repurchased and Retired During Period, Value | $						$ 3,177,000
Treasury Stock Acquired, Average Cost Per Share | $ / shares						$ 19.86
Stock Repurchase Program, Authorized Amount | $						$ 30,000,000
Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Purchased for Award	4,989
Share-based Compensation Arrangement by Share-based Payment Award, Per Share Weighted Average Price of Shares Purchased | $ / shares	$ 17.81
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Performance Payout Percentage						130.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Performance Payout Percentage						150.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted							33,709
Granted, per share | $ / shares						$ 19.73	$ 15
Convertible into Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						29,206
Granted, per share | $ / shares						$ 24.35
Convertible into Restricted Stock Units [Member] | 2015 Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						11,383
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, options						(148,271)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value | $		7,000				$ 20,000	$ 7,000
Employee Stock Option [Member] | Certain Employees and Senior Officers [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, options						148,271	127,559
Grants, options, per share | $ / shares						$ 8.48	$ 4.55	$ 2.26	$ 1.86
Lower range, price | $ / shares						18.21	19.04
Upper range, price | $ / shares						22.42	$ 30.93
Spin Off Options [Member] | Exercise Prices Ranging from $19.04 to $30.94 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Lower range, price | $ / shares						$ 18.21
Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Incentive Plan stock option compensation costs to be recognized over remaining vesting period | $		$ 427,000				$ 124,000	$ 427,000
Management Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized, share plans						2,000,000
Management Plan [Member] | Time Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						66,503	76,585	0
Granted, per share | $ / shares						$ 18.91	$ 15
Management Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						30,856
Management Plan [Member] | Convertible into Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted							24,953
Management Plan [Member] | Spin Off Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value assumptions, risk free interest rate							2.18%	1.79%	1.79%
Fair value assumptions, expected dividend rate						0.00%	0.00%	0.00%	0.00%
Fair value assumptions, expected volatility factor | $						0.44	0.40	0.40	0.40
Management Plan [Member] | Spin Off Options [Member] | Exercise Prices Ranging from $19.04 to $30.94 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Upper range, price | $ / shares						$ 30.93
Management Plan [Member] | Spin Off Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value assumptions, risk free interest rate						1.95%
Management Plan [Member] | Spin Off Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value assumptions, risk free interest rate						2.11%
Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized, share plans						400,000
Director Plan [Member] | Restricted Stock [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted						38,938	32,067
Granted, per share | $ / shares							$ 13.72
Director Plan [Member] | Common Class A [Member] | Restricted Stock [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, per share | $ / shares						$ 20.03
OSG Inc. [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reorganization Items, net | $						$ 131,000	$ 131,000	$ 5,659,000

CAPITAL STOCK AND STOCK COMPE90

CAPITAL STOCK AND STOCK COMPENSATION (Restricted Stock Activity) (Details) - Restricted Common Stock and Restricted Stock Units [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested Shares Outstanding Beginning Balance		117,258	174,177
INSW RSUs issued to replace OSG RSUs		110,294
Granted	165,503	32,067
Vested	(108,584)	(25,103)
Lower range, price	$ 18.21	$ 19.04
Upper range, price	$ 19.13

CAPITAL STOCK AND STOCK COMPE91

CAPITAL STOCK AND STOCK COMPENSATION (Stock Option Activity) (Details) - Employee Stock Option [Member] - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding Beginning Balance	127,559
Granted	(148,271)
Options issued to replace OSG options		127,559
Exercised
Canelled	(127,559)		(275,830)
Options Outstanding Ending Balance	275,830	127,559
Options Exercisable			95,618

ACCUMULATED OTHER COMPREHENSI92

ACCUMULATED OTHER COMPREHENSIVE LOSS (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Accumulated Other Comprehensive Loss [Abstract]
Unrecognized prior service credits	$ 1,467
Unrecognized prior service credits, net of tax	1,100
Unrecognized actuarial losses	11,734
Unrecognized actuarial losses, net of tax	10,318
Prior service credit expected to be recognized, next fiscal year	70
Actuarial losses expected to be recognized, next fiscal year	408
Derivative instruments, gain (loss) reclassification from accumulated oci to income, estimated net amount to be transferred	$ 8,509

ACCUMULATED OTHER COMPREHENSI93

ACCUMULATED OTHER COMPREHENSIVE LOSS (Components of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Loss [Abstract]
Unrealized losses on derivative instruments	$ (28,989)	$ (40,317)
Items not yet recognized as a component of net periodic benefit cost (pension plans)	(11,418)	(11,950)
Accumulated other comprehensive loss	$ (40,407)	$ (52,267)

ACCUMULATED OTHER COMPREHENSI94

ACCUMULATED OTHER COMPREHENSIVE LOSS (Changes in Components of AOCI, Net of Related Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Balance	$ 1,179,512	$ 1,383,786	$ 1,390,943
Other Comprehensive Income/(Loss), net of tax	11,860	11,857	10,249
Balance	1,085,654	1,179,512	1,383,786
Accumulated Other Comprehensive Loss [Member]
Balance	(52,267)	(64,124)	(74,373)
Current period change, excluding amounts reclassified from accumulated other comprehensive loss	(1,123)	(5,374)	(8,336)
Amounts reclassified from accumulated other comprehensive loss	12,983	17,231	18,585
Other Comprehensive Income/(Loss), net of tax	11,860	11,857	10,249
Balance	(40,407)	(52,267)	(64,124)
Unrealized losses on cash flow hedges [Member]
Balance	(40,317)	(53,446)	(61,356)
Current period change, excluding amounts reclassified from accumulated other comprehensive loss	(1,140)	(3,052)	(10,193)
Amounts reclassified from accumulated other comprehensive loss	12,468	16,181	18,103
Other Comprehensive Income/(Loss), net of tax	11,328	13,129	7,910
Balance	(28,989)	(40,317)	(53,446)
Items not yet recognized as a component of net periodic benefit cost (pension plans) [Member]
Balance	(11,950)	(10,636)	(12,988)
Current period change, excluding amounts reclassified from accumulated other comprehensive loss	17	(2,364)	1,870
Amounts reclassified from accumulated other comprehensive loss	515	1,050	482
Other Comprehensive Income/(Loss), net of tax	532	(1,314)	2,352
Balance	$ (11,418)	(11,950)	(10,636)
Foreign currency translation adjustment [Member]
Balance		(42)	(29)
Current period change, excluding amounts reclassified from accumulated other comprehensive loss		42	(13)
Other Comprehensive Income/(Loss), net of tax		$ 42	(13)
Balance			$ (42)

ACCUMULATED OTHER COMPREHENSI95

ACCUMULATED OTHER COMPREHENSIVE LOSS (Amounts Reclassified out of AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Items not yet recognized as a component of net periodic benefit cost (pension and other postretirement plans):
Total reclassification from AOCI	$ (12,983)	$ (17,231)	$ (18,585)
Equity in Income of Affiliated Companies [Member] | Interest Rate Swap [Member]
Unrealized losses on cash flow hedges:
Unrealized gain (loss) on cash flow hedge instruments	(12,337)	(15,664)	(18,101)
Interest Expense [Member] | Interest Rate Cap [Member]
Unrealized losses on cash flow hedges:
Unrealized gain (loss) on cash flow hedge instruments	(131)	(517)	(2)
General and Administrative Expense [Member]
Items not yet recognized as a component of net periodic benefit cost (pension and other postretirement plans):
Net periodic benefit costs associated with pension and postretirement benefit plans for shore-based employees	$ (515)	$ (1,050)	$ (482)

LEASES (Narrative) (Details)

LEASES (Narrative) (Details)	Dec. 31, 2017property
Charter-In [Member]
Leases [Line Items]
Commitments to charter in vessels, Number of Units	6

LEASES (Bareboat and Time Chart

LEASES (Bareboat and Time Charters-In) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Bareboat Charters-In [Member]
Leases [Line Items]
2,018	$ 1,841
Net minimum lease payments	$ 1,841
2018, operating days	279 days
Operating days, total	279 days
Time Charters-In [Member]
Leases [Line Items]
2,018	$ 11,849
Net minimum lease payments	$ 11,849
2018, operating days	1218 days
Operating days, total	1218 days

LEASES (Future Minimum Revenues

LEASES (Future Minimum Revenues on Charters-Out) (Details) - Charters-Out [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Receivable [Abstract]
2,018	$ 6,218
Future minumum revenues	$ 6,218
2018, revenue days	604 days
Revenue Days	604 days

LEASES (Future Minimum Lease Ob

LEASES (Future Minimum Lease Obligations for Office Space) (Details) - Office Space [Member] $ in Thousands	Dec. 31, 2017USD ($)
Leases [Line Items]
2,018	$ 1,249
2,019	1,166
2,020	1,152
2,021	665
Net minimum lease payments	$ 4,232

PENSION AND OTHER POSTRETIRE100

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Scheme Plan [Member] | Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, contributions by employer	$ 787	$ 7,605	$ 1,161
Scheme Plan [Member] | Scenario, Forecast [Member] | Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, contributions by employer	$ 810
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	10.00%
Minimum [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	86.00%
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	14.00%
Maximum [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, target plan asset allocations	90.00%

PENSION AND OTHER POSTRETIRE101

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Change in benefit obligation:
Cost of benefits earned (service cost)	$ 64
Interest cost on benefit obligation	797	$ 886	$ 1,164
Change in plan assets:
Fair value of plan assets at year end	29,527
Foreign Plan [Member] | Scheme Plan [Member]
Change in benefit obligation:
Benefit obligation at beginning of year	29,240	29,899
Interest cost on benefit obligation	797	932
Actuarial (gains)/losses	(519)	5,525
Benefits paid	(770)	(603)
Settlements		(1,579)
Foreign exchange losses/(gains)	2,779	(4,934)
Benefit obligation at year end	31,527	29,240	29,899
Change in plan assets:
Fair value of plan assets at beginning of year	25,466	21,090
Actual return on plan assets	1,714	2,503
Employer contributions	787	7,605	1,161
Benefits paid	(770)	(603)
Settlements		(1,775)
Plan administration costs	(64)
Foreign exchange losses	2,394	(3,354)
Fair value of plan assets at year end	29,527	25,466	$ 21,090
Unfunded status at December 31	$ (2,000)	$ (3,774)

PENSION AND OTHER POSTRETIRE102

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Domestic Plans with Accumulated Benefit Obligations) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Pension and Other Postretirement Benefit Plans [Abstract]
Projected benefit obligation	$ 31,527	$ 29,240
Accumulated benefit obligation	31,527	29,240
Fair value of plan assets	$ 29,527	$ 25,466

PENSION AND OTHER POSTRETIRE103

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Components of Expense, Domestic Plans) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Components of expense:
Defined benefit plan, service cost	$ 64
Defined benefit plan, interest cost	797	$ 886	$ 1,164
Expected return on plan assets	(1,041)	(951)	(1,159)
Amortization of prior-service costs	68	67	79
Recognized net actuarial loss	447	343	403
Recognized settlement loss		640
Net periodic (benefit)/cost	$ 335	$ 985	$ 487

PENSION AND OTHER POSTRETIRE104

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Weighted-Average Assumptions Used to Determine Benefit Obligations) (Details)	Dec. 31, 2017	Dec. 31, 2016
Pension and Other Postretirement Benefit Plans [Abstract]
Discount rate	2.40%	2.60%

PENSION AND OTHER POSTRETIRE105

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Assumptions Used to Determine Net Periodic Benefit Cost) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension and Other Postretirement Benefit Plans [Abstract]
Discount rate	2.60%	3.80%	3.55%
Expected (long-term) return on plan assets	3.85%	5.62%	5.35%
Rate of future compensation increases

PENSION AND OTHER POSTRETIRE106

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Expected Benefit Payments) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Pension and Other Postretirement Benefit Plans [Abstract]
2,018	$ 667
2,019	700
2,020	735
2,021	772
2,022	810
Years 2023-2027	4,703
Defined Benefit Plan Expected Future Benefit Payments	$ 8,387

PENSION AND OTHER POSTRETIRE107

PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Fair Values of Pension Plan Assets) (Details) $ in Thousands	Dec. 31, 2017USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	$ 29,527
Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	971
Government Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	28,556
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	971
Fair Value, Inputs, Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	971
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	28,556	[1]
Fair Value, Inputs, Level 2 [Member] | Government Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, fair value of plan assets	$ 28,556	[1]
[1]	Quoted prices for the managed fund is not available from an active market source since such investments are pooled investment funds. The unitized pooled investment vehicles have been valued at the latest available bid price or single price provided by the pooled investment manager. Shares in other pooled arrangements have been valued at the latest available net asset value, determined in accordance with fair value principles, provided by the pooled investment manager.

2016 AND 2015 QUARTERLY RESULTS

2016 AND 2015 QUARTERLY RESULTS OF OPERATIONS (Schedule of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information [Line Items]
Shipping revenues	$ 69,426	$ 59,968	$ 71,957	$ 88,750	$ 85,810	$ 80,771	$ 103,062	$ 128,676	$ 290,101	$ 398,319	$ 497,634
Gain/(loss) on disposal of vessels, including impairments	(81,449)	(5,406)			(29,734)	(49,640)		171	(86,855)	(79,203)	4,459
Income/(loss) from vessel operations	(88,178)	(23,749)	(9,645)	13,344	(28,509)	(47,758)	29,079	53,129	(108,228)	5,941	176,314
Interest expense	(11,367)	(11,030)	(9,076)	(8,965)	(9,525)	(9,519)	(9,690)	(10,742)	(40,438)	(39,476)	(42,970)
Reorganization items, net					(233)	(3,849)	(520)	4,471		(131)	(5,659)
Income Tax Provision	(13)	(23)	(4)	(4)	(283)	20	(173)	(4)	(44)	(440)	(140)
Net (Loss)/Income	$ (90,720)	$ (21,816)	$ (11,619)	$ 18,067	$ (57,757)	$ (50,862)	$ 30,506	$ 59,890	$ (106,088)	$ (18,223)	$ 173,170
Basic and Diluted net income (in dollars per share)	$ (3.12)	$ (0.75)	$ (0.40)	$ 0.62	$ (1.98)	$ (1.74)	$ 1.05	$ 2.05	$ (3.64)	$ (0.62)	$ 5.94
Other than temporary impairment - Equity method investment, Impairment Charges									$ 30,475	$ 30,475
Euronav Nv / FSO Joint Venture [Member]
Quarterly Financial Information [Line Items]
Other than temporary impairment - Equity method investment, Impairment Charges										$ 30,475

OTHER INCOME_(EXPENSE) (Schedul

OTHER INCOME/(EXPENSE) (Schedule of Other Nonoperating Income (Expense)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Investment income:
Interest	$ 676	$ 376	$ 66
Investment income interest and dividend and gain loss on investments	676	376	66
Write off of deferred debt issuance cost	(7,020)	(5,097)
Gain (loss) on repurchase of debt instrument		3,755
Discount on repurchase of debt		3,755
Other Income	$ (6,344)	$ (966)	$ 66

REORGANIZATION ITEMS, NET (Narr

REORGANIZATION ITEMS, NET (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Chapter 11 Filing Going Concern and Other Related Matters [Line Items]
Reorganization items, total	$ 233	$ 3,849	$ 520	$ (4,471)		$ 131	$ 5,659
Allocated reorganization items, non-cash						131	5,659
INSW Facilities [Member]
Chapter 11 Filing Going Concern and Other Related Matters [Line Items]
Debt instrument, face amount	628,375					628,375
Line of credit facility, maximum borrowing capacity	$ 50,000					50,000
OSG Inc. [Member]
Chapter 11 Filing Going Concern and Other Related Matters [Line Items]
Reorganization items, total					$ 131	$ 131	$ 5,659

REORGANIZATION ITEMS, NET (Sche

REORGANIZATION ITEMS, NET (Schedule of Reorganization Items, Net) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Chapter 11 Filing Going Concern and Other Related Matters [Abstract]
Allocated trustee fees					$ 74	$ 147
Allocated professional fees					(3,220)	5,422
Other claims adjustments					3,277	90
Reorganization Items, net	$ 233	$ 3,849	$ 520	$ (4,471)	$ 131	$ 5,659

CONTINGENCIES (Narrative) (Deta

CONTINGENCIES (Narrative) (Details) £ in Thousands, $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2015GBP (£)	Dec. 31, 2015USD ($)	Dec. 31, 2017GBP (£)	Dec. 31, 2017USD ($)
Galveston [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 25,000
Merchant Navy Ratings Pension Fund [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss			$ 1,487
Loss Contingency Accrual				£ 290	$ 388
Loss Contingency Accrual, Payments		£ 639	$ 988

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - Subsequent Event [Member]	Mar. 08, 2018
Minimum [Member]
Subsequent Event [Line Items]
Sale Leaseback Transaction, Lease Duration	70 months
Maximum [Member]
Subsequent Event [Line Items]
Sale Leaseback Transaction, Lease Duration	73 months