AOCI Attributable to Parent [Abstract] Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Tax expense (benefit) on unrealized gains on cash flow hedges Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax CHAPTER 11 FILING & EMERGENCE FROM BANKRUPTCY [Abstract] Chapter 11 Filing Going Concern and Other Related Matters [Table] Chapter 11 Filing Going Concern and Other Related Matters [Table] Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] SEC Investigation Sec Investigation [Member] SEC Investigation [Member] Chapter 11 Filing Going Concern and Other Related Matters [Line Items] Chapter 11 Filing Going Concern and Other Related Matters [Line Items] Number of subsidiaries (subsidiary) Voluntary Petitions For Reorganization, Number Of Subsidiaries Voluntary Petitions For Reorganization, Number Of Subsidiaries Litigation settlement paid Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net Number of cases closed (case) Bankruptcy Claims, Number of Claims Settled Reorganization items Reorganization Items Revenue from Contract with Customer [Abstract] Revenue, Initial Application Period Cumulative Effect Transition [Table] Revenue, Initial Application Period Cumulative Effect Transition [Table] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Axis] Initial Application Period Cumulative Effect Transition [Domain] Initial Application Period Cumulative Effect Transition [Domain] Calculated under Revenue Guidance in Effect Before Topic 606 Calculated under Revenue Guidance in Effect before Topic 606 [Member] Difference Between Revenue Guidance in Effect Before and after Topic 606 Difference between Revenue Guidance in Effect before and after Topic 606 [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 Accounting Standards Update 2014-09 [Member] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Revenue, Initial Application Period Cumulative Effect Transition [Line Items] Assets Assets [Abstract] Voyage receivables Accounts Receivable, Net, Current Liabilities Liabilities [Abstract] Deferred income taxes, net Deferred Income Tax Liabilities, Net Equity Equity [Abstract] Accumulated deficit Retained Earnings (Accumulated Deficit) Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Net Income (Loss) Attributable to Parent Items included in net income not affecting cash flows: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Amortization of debt discount and other deferred financing costs Amortization of Debt Issuance Costs and Discounts Compensation relating to restricted stock awards and stock option grants Share-based Compensation Deferred income tax provision Deferred Income Tax Expense (Benefit) Reorganization items, non-cash Reorganization Items Noncash Amount represents the non-cash portion of reorganization items. Other – net Other Noncash Income (Expense) Loss on extinguishment of debt, net Gain (Loss) on Extinguishment of Debt Distributed earnings of affiliated companies Proceeds from Equity Method Investment, Distribution Payments for drydocking Payments For Drydocking Amounts paid for drydock costs performed pursuant to regulatory requirements. SEC, Bankruptcy and IRS claim payments Bankruptcy and IRS Claims Amount Paid Amount paid to settle bankruptcy and IRS claim. Changes in operating assets and liabilities Increase (Decrease) in Operating Capital Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash Flows from Investing Activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Expenditures for other property Payments to Acquire Other Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Payments on debt Proceeds from (Repayments of) Long-term Debt and Capital Securities Extinguishment of debt Repayments of Unsecured Debt Tax withholding on share-based awards Payments Related to Tax Withholding for Share-based Compensation Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Net (decrease)/increase in cash, cash equivalents and restricted cash (Note 3) Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect Cash, cash equivalents and restricted cash at beginning of period (Note 3) Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash, cash equivalents and restricted cash at end of period (Note 3) Related Party Transactions [Abstract] Statement [Table] Statement [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Alaska Tanker Company Llc Alaska Tanker Company Llc [Member] LNG Joint Venture Lng Joint Venture [Member] Lng Joint Venture [Member]. Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] International Seaways Incorporated International Seaways Incorporated [Member] International Seaways Incorporated [Member]. Statement [Line Items] Statement [Line Items] Company's interest Equity Method Investment, Ownership Percentage Annual fee from related party Annual Fee for Related Party Annual Fee for Related Party. Accounting Policies [Abstract] Schedule of New Accounting Pronouncements and Changes in Accounting Principles Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements, Derivatives and Fair Value Disclosures Fair Value Disclosures [Text Block] Revenue Recognition Revenue from Contract with Customer [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Class A Common Class A [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Units (RSUs) Restricted Stock Units (RSUs) [Member] Employee Stock Option Employee Stock Option [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Participating securities, distributed and undistributed earnings (loss), diluted (in shares) Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Potentially dilutive securities (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Dilutive awards (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Antidilutive securities excluded from computation of earnings per share, amount (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Capital Stock and Stock Compensation Shareholders' Equity and Share-based Payments [Text Block] Debt Disclosure [Abstract] Debt Debt Disclosure [Text Block] Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] Hyundai Mipo Dockyard Company Ltd Hyundai Mipo Dockyard Company Ltd [Member] Hyundai Mipo Dockyard Company Ltd [Member] Gunderson Marine LLC Gunderson Marine LLC [Member] Gunderson Marine LLC [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Construction in Progress Construction in Progress [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Number of chemical tankers (tanker) Number Of Chemical Tankers Number Of Chemical Tankers Mass of Chemical tankers (t) Property Plant And Equipment, Mass Property Plant And Equipment, Mass Commitments under the contract, remainder of the year Contractual Obligation, Future Minimum Payments Due, Remainder of Fiscal Year Commitments under the contract in 2019 Contractual Obligation, Due in Next Fiscal Year Number of chemical tank barges (barge) Number Of Chemical Tank Barges Number Of Chemical Tank Barges Volume of chemical tank barge (bbl) Property Plant And Equipment, Volume Property Plant And Equipment, Volume Commitments under the contract in 2020 Contractual Obligation, Due in Second Year Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Secured Debt Secured Debt [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] OBS ABL Facility Obs Abl Facility [Member] OBS ABL Facility [Member]. OBS Term loan Obs Term Loan [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt instrument, face amount Debt Instrument, Face Amount Amounts drawn under credit facility Long-term Line of Credit Debt instrument, amortization, quarterly percentage of original principal amount Debt Instrument Amortization Quarterly Percentage Of Original Principal Amount Debt instrument, amortization, quarterly percentage of original principal amount. Repayments of debt Repayments of Debt Debt instrument, covenant threshold related to net cash proceeds from asset sales Debt Instrument Covenant Threshold Related To Net Cash Proceeds From Asset Sales Debt instrument, covenant threshold related to net cash proceeds from asset sales. Mandatory prepayment of debt Mandatory Prepayment of Debt Mandatory prepayment of debt. Optional prepayment of debt Debt Instrument, Optional Debt Prepayment Debt Instrument, Optional Debt Prepayment Loss on repurchase of debt instrument Gain (Loss) on Repurchase of Debt Instrument Debt instrument, additional mandatory prepayments, percentage (up to) Debt Instrument Additional Mandatory Prepayments Percentage Debt instrument, additional mandatory prepayments percentage. Threshold amounts available for parent Borrowing Covenant Threshold Amount Available For Parent Related To Cash Dividends And Loans And Advances Borrowing covenant threshold amount available for parent related to cash dividends, loans and advances from certain subsidiaries. Outstanding principal amount Long-term Debt Chapter 11 Filing and Emergence from Bankruptcy Bankruptcy Filing And Going Concern [Text Block] The entire disclosure for bankruptcy filing and going concern. Earnings per Common Share Earnings Per Share [Text Block] Related Parties Related Party Transactions Disclosure [Text Block] Statement of Financial Position [Abstract] Unbilled contracts receivable Unbilled Contracts Receivable Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Total AOCI Attributable to Parent [Member] Unrealized losses on cash flow hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Items not yet recognized as a component of net periodic benefit cost (pension and other postretirement plans) Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance, beginning Stockholders' Equity Attributable to Parent Current period change, excluding amounts reclassified from accumulated other comprehensive income Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Total change in accumulated other comprehensive income Other Comprehensive Income Loss Including Capital Adjustments Related to Spinoff Net Of Tax Other comprehensive income (loss) including capital adjustments related to spinoff net of tax. Balance, ending Income Tax Disclosure [Abstract] Income tax provision Income Tax Expense (Benefit) Effective tax rates Effective Income Tax Rate Reconciliation, Percent Reserve for uncertain tax positions Liability for Uncertainty in Income Taxes, Noncurrent Net operating loss carryforwards Operating Loss Carryforwards Accrued interest Unrecognized Tax Benefits, Interest on Income Taxes Accrued Reduction in unrecognized tax benefits Decrease in Unrecognized Tax Benefits is Reasonably Possible Unrecognized tax positions reasonably possible to be recognized within next twelve months Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Class of Warrant or Right [Axis] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Class A Warrant Class Warrant [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Management Incentive Compensation Plan Management Incentive Compensation Plan [Member] Time Based Restricted Stock Time Based Restricted Stock [Member] Time Based Restricted Stock [Member]. Performance Based Restricted Units Performance Based Restricted Units [Member] RSUs related to ROIC Restricted Stock Unit Related To Return On Invested Capital [Member] Restricted Stock Unit related to Return On Invested Capital [Member]. Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Director Director [Member] Senior Officers Senior Officers [Member] Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Share-based Compensation Award, Tranche One Share-based Compensation Award, Tranche One [Member] Share-based Compensation Award, Tranche Two Share-based Compensation Award, Tranche Two [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares repurchased during period (in shares) Stock Repurchased During Period, Shares Stock repurchased during period, per share amount (in dollars per share) Stock Repurchased During Period Per Share Amount Stock repurchased during period, per share amount. Stock issued during period, shares, conversion of convertible securities (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Conversion of stock, shares converted (in shares) Conversion of Stock, Shares Converted Granted, options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Granted options, average grant date fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Granted, per share (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Continues employment period Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Share-based compensation arrangement, award vesting rights percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Additional shares available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Aggregate shares available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Options, exercisable price (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Consolidation Consolidation, Policy [Policy Text Block] Recently Adopted Accounting Standards and Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Contingencies Commitments and Contingencies, Policy [Policy Text Block] Increase in revenues Revenues Increase in net income Increase in basic and diluted net income (in dollars per share) Earnings Per Share, Basic and Diluted Period for voyage completion Revenue From Contract With Customer, Performance Obligation Period Revenue From Contract With Customer, Performance Obligation Period Number of products participating in U.S Maritime Security Program (MSP) (product) Number Of Products Participating In U.S Maritime Security Program (MSP) Number Of Products Participating In U.S Maritime Security Program (MSP) Contract balances from contracts with customers Contract with Customer, Asset, Net Voyage charters not yet completed Revenue, Remaining Performance Obligation Components of Calculation of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Statement of Comprehensive Income [Abstract] Other comprehensive income, net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Net change in unrealized gains on cash flow hedges Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments Defined benefit pension and other postretirement benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax [Abstract] Net change in unrecognized prior service costs Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax Net change in unrecognized actuarial losses Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Unrealized losses on derivative instruments Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Items not yet recognized as a component of net periodic benefit cost (pension and other postretirement benefit plans) Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Table] Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Cap Interest Rate Cap [Member] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] OSG Bulk Ships, Inc (OBS) Osg Bulk Ships Inc [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Plan Scenario, Plan [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Maximum Maximum [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest Expense Interest Expense [Member] Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items] Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items] Derivative, notional amount Derivative, Notional Amount Derivative, cap interest rate Derivative, Cap Interest Rate Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Leases [Abstract] Leases [Table] Leases [Table] Schedule that describes and identifies leases. Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Charter-In Charter In [Member] Charter In [Member]. Charters-Out Charters Out [Member] Charters Out [Member]. Vessels Maritime Equipment [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] One Time Lease Option, Option One One Time Lease Option, Option One [Member] One Time Lease Option, Option One [Member] Indefinite Lease Option, Option One Indefinite Lease Option, Option One [Member] Indefinite Lease Option, Option One [Member] Indefinite Lease Option, Option Two Indefinite Lease Option, Option Two [Member] Indefinite Lease Option, Option Two [Member] Type of Arrangement and Non-arrangement Transactions [Axis] Type of Arrangement and Non-arrangement Transactions [Axis] Arrangements and Non-arrangement Transactions [Domain] Arrangements and Non-arrangement Transactions [Domain] Contracts of Affreightment Excluded Contracts Of Affreightment [Member] Contracts of Affreightment [Member]. Leases [Line Items] Leases [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Commitments to charter in vessels, number of units (vessel) Property Subject to or Available for Operating Lease, Number of Units Commitments to charter in vessels, number of units with expiring leases in next fiscal year (vessel) Property Subject To Or Available For Operating Lease, Number Of Units With Lease Expiration In Next Fiscal Year Property Subject To Or Available For Operating Lease, Number Of Units With Lease Expiration In Next Fiscal Year Operating lease renewal term Lessee, Operating Lease, Renewal Term Lease receivable in 2018 Operating Leases, Future Minimum Payments Receivable, Current Lease receivable in 2019 Operating Leases, Future Minimum Payments Receivable, in Two Years Lease receivable in 2020 Operating Leases, Future Minimum Payments Receivable, in Three Years Leases Leases Of Lessee and Lessor Disclosure [Text Block] The entire disclosure of operating and capital leases where Overseas Ship holding leases of lessee and lessor during the period. Components of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Reclassification Out of Accumulated Other Comprehensive Income (Loss) Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Accounting Standards Update 2016-18 Accounting Standards Update 2016-18 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Decrease in net cash provided by investing activities Net Cash Provided by (Used in) Investing Activities Contractual obligation Contractual Obligation Schedule of Property Subject to or Available for Operating Lease Schedule of Property Subject to or Available for Operating Lease [Table Text Block] Operating Leases of Lessee Disclosure Lessee, Operating Lease, Disclosure [Table Text Block] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Weighted average common shares outstanding: Weighted Average Number Basic and Diluted Shares Outstanding [Abstract] Class A common stock - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Class A common stock - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Contracts Of Affreightment Amount Operating Leases, Future Minimum Payments Receivable [Abstract] 2018 2019 2020 2021 Operating Leases, Future Minimum Payments Receivable, in Four Years 2022 Operating Leases, Future Minimum Payments Receivable, in Five Years Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Net minimum lease receipts Operating Leases, Future Minimum Payments Receivable Revenue Days Operating Leases, Future Minimum Payments Receivable, Revenue Days [Abstract] Operating Leases, Future Minimum Payments Receivable, Revenue Days [Abstract] 2018 Operating Leases Revenue Days Current Operating leases revenue days current. 2019 Operating Leases Due In Two Years Revenue Days Operating leases due in two years, revenue days. 2020 Operating Leases Due In Three Years Revenue Days Operating leases due in three years revenue days. 2021 Operating Leases Due In Four Years Revenue Days Operating leases due in four years revenue days. 2022 Operating Leases Due In Five Years Revenue Days Operating leases due in five years revenue days. Thereafter Operating Leases Due Thereafter Revenue Days Operating leases due thereafter revenue days. Net minimum lease receipts Number Of Revenue Days Number of revenue days. Income Statement [Abstract] Shipping Revenues: Revenues [Abstract] Time and bareboat charter revenues Operating Leases, Income Statement, Lease Revenue Voyage charter revenues Cargo and Freight Revenue Shipping revenues Operating Expenses: Costs and Expenses [Abstract] Voyage expenses Voyage Expenses Expenses associated with operating vessels which are attributable to particular voyages such as port and canal charges, fuel (bunker) expenses, and brokerage commissions payable to unaffiliated third parties. Vessel expenses Vessel Expenses Direct vessel operating expenses, which includes crew costs, provisions, deck and engine stores, lubricating oil, insurance and maintenance and repairs, incurred during the reporting period. Charter hire expenses Operating Leases, Rent Expense General and administrative General and Administrative Expense Total operating expenses Costs and Expenses Operating income Operating Income Loss Including Equity In Income Loss Of Affiliated Companies The net result for the period of deducting operating expenses from operating revenues including equity in income (loss) of affiliated companies. Other income/(expense) Other Nonoperating Income (Expense) Income before interest expense, reorganization items and income taxes Loss Before Interest Expense, Reorganization Items and Taxes Loss before interest expense, reorganization items and taxes during the period. Interest expense Interest Expense Income before reorganization items and income taxes Income Loss From Continuing Operations Before Income Taxes This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, and noncontrolling interest. Reorganization items, net Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax provision Net income Weighted Average Number of Common Shares Outstanding: Basic - Class A (in shares) Diluted - Class A (in shares) Per Share Amounts: Basic and diluted net income - Class A (in dollars per share) Document And Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] 7.5% Election 2 Notes Due 2021 7.50% Election 2 Notes Due 2021 [Member] 7.50% Election 2 Notes Due 2021 [Member] 7.5% notes due 2024 Notes7.5% Due 2024 [Member] Notes7.5% Due 2024 [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Corporate, Non-Segment Corporate, Non-Segment [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Assets Assets, Fair Value Disclosure [Abstract] Cash Cash and Cash Equivalents, Fair Value Disclosure Total Assets, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Loans payable Loans Payable, Fair Value Disclosure Notes payable Notes Payable, Fair Value Disclosure Total Financial and Nonfinancial Liabilities, Fair Value Disclosure Restricted cash Restricted Cash and Cash Equivalents, Current As Previously Reported Scenario, Previously Reported [Member] Impact of Adoption Scenario, Adjustment [Member] Accounting Standards Update 2017-07 Accounting Standards Update 2017-07 [Member] Accounting Standards Update 2017-07 [Member] Total Operating Expenses Operating income Other expense Vessels Property, Plant and Equipment Disclosure [Text Block] ASSETS Current Assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Voyage receivables, including unbilled of $6,135 and $9,919 Income tax receivable Income Taxes Receivable, Current Receivable from INSW Due from Related Parties, Current Other receivables Nontrade Receivables, Current Inventories, prepaid expenses and other current assets Inventories And Prepaid Expenses and Other Current Assets Inventories, prepaid expenses and other current assets. Total Current Assets Assets, Current Vessels and other property, less accumulated depreciation Property, Plant and Equipment, Net Deferred drydock expenditures, net Deferred Drydock Expenditures Net Carrying amount, net of accumulated amortization, as of the balance sheet date of capitalized drydock costs performed pursuant to regulatory requirements that are expected to be recovered over the period between dry dockings, typically over periods from 2.5 to 5 years. Total Vessels, Other Property and Deferred Drydock Vessels Deferred Dry Dock and Other Property Sum of the carrying amounts as of the balance sheet date of all assets that are vessels, deferred drydock and other property recognized. Restricted cash - non current Restricted Cash and Cash Equivalents, Noncurrent Investments in and advances to affiliated companies Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Intangible assets, less accumulated amortization Intangible Assets, Net (Excluding Goodwill) Other assets Other Assets, Noncurrent Total Assets Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current Liabilities: Liabilities, Current [Abstract] Accounts payable, accrued expenses and other current liabilities Accounts Payable and Other Accrued Liabilities, Current Current installments of long-term debt Long-term Debt, Current Maturities Total Current Liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Other liabilities Other Liabilities, Noncurrent Total Liabilities Liabilities Equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock - Class A ($0.01 par value; 166,666,666 shares authorized; 80,713,679 and 78,277,669 shares issued and outstanding Common Stock, Value, Issued Paid-in additional capital Additional Paid in Capital Stockholders Equity Subtotal Stockholders Equity Subtotal Stockholder's Equity Subtotal after treasury stock value. Accumulated other comprehensive loss Total Equity Total Liabilities and Equity Liabilities and Equity Recently Adopted and Issued Accounting Standards Basis of Presentation and Significant Accounting Policies [Text Block] Amount Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2018 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2019 Operating Leases, Future Minimum Payments, Due in Two Years 2020 Operating Leases, Future Minimum Payments, Due in Three Years 2021 Operating Leases, Future Minimum Payments, Due in Four Years 2022 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Net minimum lease payments Operating Leases, Future Minimum Payments Due Operating Days Operating Leases, Future Minimum Payments Due, Operating Days [Abstract] Operating Leases, Future Minimum Payments Due, Operating Days [Abstract] 2018 Operating Leases Due Current Operating Days Operating leases due current, operating days. 2019 Operating Leases Due In Two Years Operating Days Operating leases due in two years operating days. 2020 Operating Leases Due In Three Years Operating Days Operating leases due in three years operating days. 2021 Operating Leases Due In Four Years Operating Days Operating leases due in four years operating days. 2022 Operating Leases Due In Five Years Operating Days Operating leases due in five years operating days. Thereafter Operating Leases Due Thereafter Operating Days Operating leases due thereafter operating days. Net minimum lease payments Operating Leases Due Operating Days Operating leases due operating days. Commitments and Contingencies Disclosure [Abstract] Contingencies Commitments and Contingencies Disclosure [Text Block] Taxes Income Tax Disclosure [Text Block] Statement of Stockholders' Equity [Abstract] Common Stock Common Stock [Member] Paid-in Additional Capital Additional Paid-in Capital [Member] Accumulated Deficit Retained Earnings [Member] Accumulated Other Comprehensive Loss Adoption of accounting standard (Note 4) Cumulative Effect of New Accounting Principle in Period of Adoption Other comprehensive income Forfeitures, cancellations, issuance and vesting of restricted stock awards, net Stock Issued During Period Value Restricted Stock Award Issued And Vested Net Of Forfeitures Stock issued during period value restricted stock award issued and vested, net of forfeitures. Compensation related to Class A options granted and restricted stock awards Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Conversion of Class A warrants to common stock Stock Issued During Period, Value, Conversion of Units Warrants outstanding (in shares) Class of Warrant or Right, Outstanding