Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 7.50% Election 1 Notes due 2021 [Member] Seven Point Five Percentage Election One Notes Due Two Thousand Twenty One [Member] 7.50% Election 2 Notes due 2021 Seven Point Five Percentage Election Two Notes Due Two Thousand Twenty One [Member] 7.50% Notes due 2024 and 8.125% Notes due 2018 [Member] Notes750 Percent Due2024 And Notes8125 Percent Due2018 [Member] Notes 750 Percent Due 2024 And Notes 8125 Percent Due 2018 [Member] 7.50% Notes due 2024 Notes750 Percent Due2024 [Member] 8.125% Notes due 2018 Notes8125 Percent Due2018 [Member] The Bank of New York Mellon Trust Loan [Member] The Bank of New York Mellon Trust Loan [Member] The Bank of New York Mellon Trust Loan [Member] Exit Financing Facilities [Member] Obs Abl Facility And Obs Term Loan [Member] OBS ABL Facility and OBS Term Loan [Member]. OBS ABL Facility [Member] Obs Abl Facility [Member] OBS ABL Facility [Member]. OBS Term Loan Obs Term Loan [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Parent Company [Member] Parent Company [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Debt instrument, face amount Debt Instrument, Face Amount Debt instrument, interest rate, stated percentage Debt Instrument, Interest Rate, Stated Percentage Debt instrument, redemption price, percentage Debt Instrument, Redemption Price, Percentage Early repayment of senior debt Early Repayment of Senior Debt Debt instrument, minimum aggregate percentage, for holders to call entire unpaid principal and interst due Debt Instrument Minimum Percentage Of Holders Of Debt To Call Entire Unpaid Principal And Interest Debt instrument, minimum aggregate percentage of holders of debt to call entire unpaid principal and interest. Write off of deferred debt issuance cost Write off of Deferred Debt Issuance Cost Repayments of secured debt Repayments of Secured Debt Gain (loss) on repurchase of debt instrument Gain (Loss) on Repurchase of Debt Instrument Deposits Deposits Debt instrument, annual principal payment Debt Instrument, Annual Principal Payment Accrued and unpaid interest Debt Instrument, Accrued And Unpaid Interest Debt Instrument, Accrued And Unpaid Interest Mandatory prepayment of debt Mandatory Prepayment of Debt Mandatory prepayment of debt. General and administrative General and Administrative Expense Interest paid, net Interest Paid, Net Related Party Transactions [Abstract] Schedule of Intercompany receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Common Class A [Member] Common Class A [Member] Statement [Line Items] Statement [Line Items] Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares, issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Vessel Excluding Construction In Progress [Member] Vessel Excluding Construction In Progress [Member] Vessel Excluding Construction In Progress [Member]. Vessel/Fleet [Member] Maritime Equipment [Member] Other Property [Member] Property, Plant and Equipment, Other Types [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property, plant and equipment, disposals Property, Plant and Equipment, Disposals Accumulated Depreciation, Depletion and Amortization, Sale or Disposal of Property, Plant and Equipment Accumulated Depreciation, Depletion and Amortization, Sale or Disposal of Property, Plant and Equipment Cost Property, Plant and Equipment, Gross Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Vessels and other property, less accumulated depreciation Property, Plant and Equipment, Net Impairment Property, Plant and Equipment, Transfers and Changes Vessel additions Property, Plant and Equipment, Additions Depreciation Depreciation Equity Method Investments and Joint Ventures [Abstract] Current assets Equity Method Investment, Summarized Financial Information, Current Assets Total assets Equity Method Investment, Summarized Financial Information, Assets Current liabilities Equity Method Investment, Summarized Financial Information, Current Liabilities Non-current liabilities Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities Equity/(deficiency) Equity Method Investment Summarized Financial Information, Equity Total liabilities and equity/(deficiency) Equity Method Investment, Summarized Financial Information, Liabilities and Equity Accounting Policies [Abstract] Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] International Seaways Incorporated [Member] International Seaways Incorporated [Member] International Seaways Incorporated [Member]. Intercompany receivables Due from Related Parties, Noncurrent Derivative Instruments in Hedges, at Fair Value, Net [Abstract] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Interest Rate Cap [Member] Interest Rate Cap [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest Expense [Member] Interest Expense [Member] Net Income (Loss) from Discontinued Operations [Member] Discontined Operations Net Income Loss [Member] Discontined Operations Net Income Loss [Member]. Effective portion of gain/(loss) reclassified from accumulated other comprehensive loss Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Ineffective portion Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Compensation and Retirement Disclosure [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] United States Pension Plan of US Entity, Defined Benefit [Member] United States Pension Plan of US Entity [Member] Other Benefits [Member] Other Pension Plan, Postretirement or Supplemental Plans [Member] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected (long-term) return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Rate of future compensation increases Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Other Income and Expenses [Abstract] Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] OBS Facilities [Member] Obs Facilities [Member] Obs Facilities [Member]. 7.50% Election 1 Notes Due 2021 - 2024 [Member] Seven Point Five Percent Election One Notes Due Two Thousand And Twenty One Through Two Thousand And Twenty Four [Member] Seven Point Five Percent Election One Notes Due Two Thousand And Twenty One Through Two Thousand And Twenty Four [Member]. Interest and debt expense Interest and Debt Expense Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Scenario, Forecast [Member] Scenario, Forecast [Member] Secured Debt [Member] Secured Debt [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Base Rate [Member] Base Rate [Member] 1-Month London Interbank Offered Rate LIBOR [Member] Thirty Day London Interbank Offered Rate Libor [Member] 1-Month London Interbank Offered Rate LIBOR [Member]. Federal Funds Effective Swap Rate [Member] Federal Funds Effective Swap Rate [Member] Debt instrument, covenant related to base available amount Debt Instrument Covenant Related To Base Amount Available Debt instrument, covenant related to base amount available. Debt instrument, maximum amount related to increase in borrowings Debt Instrument Maximum Amount Related To Increase Borrowings Debt instrument, maximum amount related to increase in borrowings. Debt instrumnet, suppressed availability minimum amount Debt Instrument Convenant Amount Maximum If Increase Requested Debt instrument, convenant amount maximum if increase requested. Debt instrument, basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Commitment fee percentage Line of Credit Facility, Commitment Fee Percentage Debt instrument, commitment fee, if exposure is greater or equal to 50% Debt Instrument Commitment Fee If Exposure Greater Or Equal To Fifty Percent Debt instrument, commitment fee, if exposure is greater or equal to 50%. 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. Prepayment of debt Early Repayment Of Lines of Credit Early Repayment Of Lines of Credit Debt instrument, convenant threshold related to net cash proceeds from asset sales Debt Instrument Convenant Threshold Related To Net Cash Proceeds From Asset Sales Debt instrument, covenant threshold related to net cash proceeds from asset sales. Long-term debt Long-term Debt Debtor reorganization items, debtor-in-possession facility financing costs Debtor Reorganization Items, Debtor-in-Possession Facility Financing Costs Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Capital Stock and Stock Compensation Shareholders' Equity and Share-based Payments [Text Block] Change in benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit obligation at beginning of year Defined Benefit Plan, Benefit Obligation Cost of benefits earned (service cost) Defined Benefit Plan, Service Cost Interest cost on benefit obligation Defined Benefit Plan, Interest Cost Curtailment gain Defined Benefit Plan, Curtailments Actuarial (gains)/losses Defined Benefit Plan, Actuarial Gain (Loss) Benefits paid Defined Benefit Plan, Benefits Paid Benefit obligation at year end Change in plan assets: Defined Benefit Plan, Actual Return on Plan Assets [Abstract] Fair value of plan assets at beginning of year Defined Benefit Plan, Fair Value of Plan Assets Actual return on plan assets Defined Benefit Plan, Actual Return on Plan Assets Employer contributions Defined Benefit Plan, Contributions by Employer Fair value of plan assets at year end Unfunded status at December 31 Defined Benefit Plan Unfunded Status Of Plan The unfunded status is measured as the difference between the fair value of plan assets and the benefit obligation. Will normally be the same as the net Defined Benefit Plan, Amounts Recognized in Balance Sheet, Total. Accumulated Other Comprehensive Loss [Abstract] 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 Loss [Table Text Block] Tabular disclosure of information about items reclassified out of accumulated other comprehensive income (loss). Comprehensive Income Tax Expenses (Benefits) Comprehensive Income Tax Expenses Benefits [Table Text Block] Comprehensive Income, Tax Expenses/Benefits, Table. ASSETS Assets [Abstract] Current Assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Restricted cash Restricted Cash and Cash Equivalents, Current Voyage receivables, including unbilled of $9,919 and $12,593 Accounts Receivable, Net, Current Income tax recoverable Income Taxes Receivable, Current Receivable from INSW Due from Related Parties, Current Other receivables Nontrade Receivables, Current 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 Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Vessels and other property, less accumulated depreciation 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, Deferred Drydock and Other Property 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. 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 Income taxes payable Taxes Payable, Current Current installments of long-term debt Long-term Debt, Current Maturities Total Current Liabilities Liabilities, Current Reserve for uncertain tax positions Liability for Uncertainty in Income Taxes, Noncurrent Long-term debt Long-term Debt, Excluding Current Maturities Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent 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; 78,277,669 and 70,271,172 shares issued and outstanding) Common Stock, Value, Issued Paid-in additional capital Additional Paid in Capital Accumulated deficit Retained Earnings (Accumulated Deficit) Stockholders Equity Subtotal Stockholders Equity Subtotal Stockholder's Equity Subtotal after treasury stock value. Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Equity Stockholders' Equity Attributable to Parent Total Liabilities and Equity Liabilities and Equity Earnings Per Share [Abstract] Earning Per Share [Table] Earning Per Share [Table] Common Class B [Member] Common Class B [Member] Earning Per Share [Line Items] Earning Per Share [Line Items] Net income/(loss) from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Participaint securities, continuing operations Participating Securities Used in Calculating Numerator for Earnings Per Share Basic Continuing Operations Participating securities used in calculating numerator for earnings per share basic continuing operations. Net (Loss)/Income from Discontinued Operations Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Participating securities, discontinued operations Participating Securities Used In Calculating Numerator For Earnings Per Share Basic Discontinued Operations Participating securities used in calculating numerator for earnings per share basic discontinued operations. Net income/(loss) Net Income (Loss) Attributable to Parent Weighted average common shares outstanding: Weighted Average Number Basic and Diluted Shares Outstanding [Abstract] Weighted average common shares outstanding, basic Weighted Average Number of Shares Outstanding, Basic Weighted average common shares outstanding, diluted Weighted Average Number of Shares Outstanding, Diluted Notes8125 Percent Due2018 [Member] Seven Point Five Percentage Election Two Notes Due Two Thousand Twenty One [Member] Notes750 Percent Due2024 [Member] Debt instrument, unamortized discount and deferred costs Debt Instrument Unamortized Discount and Deferred Costs Debt instrument unamortized discount and deferred costs. Unbilled contracts receivable (in dollars) Unbilled Contracts Receivable VESSELS, OTHER PROPERTY AND DEFERRED DRYDOCK Property, Plant and Equipment Disclosure [Text Block] Pension and Other Postretirement Benefits Disclosure Pension and Other Postretirement Benefits Disclosure [Text Block] Decrease in weighted average number of shares outstanding used to calculate basic net income per share amounts Decrease In Weighted Average Number Of Shares Outstanding Basic Due To Change In Capital Structure Decrease in weighted average number of shares outstanding basic due to change in capital structure. Decrease in weighted average number of shares outstanding used to calculate diluted net income per shares amounts Decrease In Weighted Average Number Of Shares Outstanding Diluted Due To Change In Capital Structure Decrease in weighted average number of shares outstanding diluted due to change in capital structure. Decrease in weighted average number of shares outstanding used to calculate basic and diluted net income per share amounts Decrease In Weighted Average Number Of Shares Outstanding Basic And Diluted Due To Change In Capital Structure Decrease in weighted average number of shares outstanding basic and diluted due to change in capital structure. Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Osg Bulk Ships Inc [Member] Osg Bulk Ships Inc [Member] Osg Financial Corporation [Member] Osg Financial Corporation [Member] Osg Financial Corporation [Member]. Osg Ship Management (Tampa) [Member] Osg Ship Management (Tampa) [Member] Osg Ship Management (Tampa) [Member] Notes750 Percent Due2024 And Notes8125 Percent Due2018 [Member] Debtor-in-possession financing, amount arranged Debtor-in-Possession Financing, Amount Arranged 2021 Long-term Debt, Maturities, Repayments of Principal in Year Four Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Related party transaction, due from (to) related party, noncurrent Related Party Transaction, Due from (to) Related Party, Noncurrent Payments for reimbursable agreements to related party Payments for Reimbursable Agreements To Related Party Payments for reimbursable agreements to related party. (Loss)/income from discontinued operations Proceeds from affilated entity operating activities Proceeds from Affilated Entity Operating Activities Proceeds from affilated entity operating activities. Proceeds from equity method investment, dividends or distributions, return of capital Proceeds from Equity Method Investment, Dividends or Distributions, Return of Capital Other significant noncash transaction, value of consideration given Other Significant Noncash Transaction, Value of Consideration Given Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Alaska Tanker Company Llc [Member] Alaska Tanker Company Llc [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] 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] Total AOCI Attributable to Parent [Member] AOCI Attributable to Parent, Net of Tax [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Balance Current period change, excluding amounts reclassified from accumulated other comprehensive loss Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive loss Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Distribution of International Seaways, Inc. Other Comprehensive Income (Loss) Distribution Of Wholly-Owned Subsidiary, Net of Tax, Total Other Comprehensive Income (Loss) Distribution Of Wholly-Owned Subsidiary, Net of Tax, Total Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Total change in accumulated other comprehensive loss Other Comprehensive Income (Loss), Including Distribution Of Wholly Owned Subsidiary, Net Of Tax Other Comprehensive Income (Loss), Including Distribution Of Wholly Owned Subsidiary, Net Of Tax Balance Income Tax Disclosure [Abstract] Income Tax Contingency [Table] Income Tax Contingency [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] US Federal [Member] Domestic Tax Authority [Member] State and Local Jurisdiction [Member] State and Local Jurisdiction [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Tax cuts and jobs act Of 2017, incomplete accounting, provisional income tax expense (benefit) Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Operating loss carryforwards Operating Loss Carryforwards Operating loss carryforwards, valuation allowance Operating Loss Carryforwards, Valuation Allowance Valuation allowance, deferred tax asset, increase (decrease), amount Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized tax benefits, interest on income taxes accrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Unrecognized tax benefits, income tax penalties and interest accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit Shedule Of Long Term Debt Maturities Repayments Of Principal [Table] Shedule Of Long Term Debt Maturities Repayments Of Principal [Table] Shedule Of Long Term Debt Maturities Repayments Of Principal [Line Items] Shedule Of Long Term Debt Maturities Repayments Of Principal [Line Items] 2018 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three 2022 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Gross Long-term Debt, Gross Discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Rate of future compensation increases Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Discontinued Operations and Disposal Groups [Abstract] Schedule of Discontinued Operations Disposal Groups, Including Discontinued Operations [Table Text Block] Schedule of Components of Income Tax (Expense)/Benefit Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Unrecognized Tax Benefits Roll Forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Shipping revenues Equity Method Investment, Summarized Financial Information, Revenue Ship operating expenses Equity Method Investment Summarized Financial Information Operating Expenses The amount of operating expenses associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Income from vessel operations Equity Method Investment Summarized Financial Information Operating Income Loss The net result for the period of deducting operating expenses from operating revenues reported by an equity method investment of the entity. Net income Equity Method Investment, Summarized Financial Information, Net Income (Loss) Taxes Income Tax Disclosure [Text Block] Multiemployer Plan Name [Axis] Multiemployer Plan Name [Axis] Multiemployer Plan Name [Domain] Multiemployer Plan Name [Domain] American Maritime Officers Pension Plan [Member] American Maritime Officers Pension Plan [Member] Marine Engineers Beneficial Association Pension Plan [Member] Marine Engineers Beneficial Association Pension Plan [Member] Seafarers Pension Plan [Member] Seafarers Pension Plan [Member] EIN / Pension Plan Number Employer Identification and Pension Plan Number Employer Identification And Pension Plan Number. Rehabilitation Plan Status Multiemployer Plans, Funding Improvement Plan and Rehabilitation Plan Contributions made by the Company Multiemployer Plan, Period Contributions 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 Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Equity Securities [Member] Equity Securities [Member] Fixed Income Securities [Member] Fixed Income Securities [Member] Cash and Cash Equivalents [Member] Cash and Cash Equivalents [Member] Number of defined benefit pension plans Number of defined benefit pension plans It represents number of defined benefit pension plan. Multiemployer plans surcharge imposed Multiemployer plans surcharge imposed It represents multiemployer plans surcharge imposed. Multiemployer plans, withdrawl obligation Multiemployer Plans, Withdrawal Obligation Defined benefit plan, target allocation percentage Defined Benefit Plan, Target Plan Asset Allocations Defined benefit plan, ultimate health care cost trend rate Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Defined benefit plan, contributions by employer Defined benefit plans, estimated future employer contribution, next fiscal year Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year Defined contribution plan, employer discretionary contribution amount Defined Contribution Plan, Employer Discretionary Contribution Amount Pension and other postretirement and postemployment benefit plans, noncurrent liabilities Pension and Other Postretirement and Postemployment Benefit Plans, Liabilities, Noncurrent Components of expense: Defined Benefit Plan, Net Periodic Benefit Cost [Abstract] Cost of benefits earned Interest cost on benefit obligation Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of prior-service costs Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized net actuarial loss Defined Benefit Plan, Amortization of Gains (Losses) Curtailment Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer Concentration Risk [Member] Customer Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Shipping Revenues [Member] Sales Revenue, Net [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Andeavor [Member] Andeavor [Member] Andeavor [Member] Petrobras america inc. [Member] Petrobras America Incorporated [Member] Petrobras America Incorporated [Member]. Shell [Member] Shell [Member] Shell [Member]. Marathon petroleum company [Member] Marathon Petroleum Company [Member] Marathon Petroleum Company [Member]. Concentration risk, percentage Concentration Risk, Percentage Statement of Comprehensive Income [Abstract] Net income/(loss) Other Comprehensive Income/(Loss), 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, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Net change in unrecognized prior service costs Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, Net of Tax Net change in unrecognized actuarial losses Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Comprehensive income/(loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Interest Rate Swap Discontinued Operations [Member] Interest Rate Swap Discontinued Operations [Member] Interest Rate Swap Discontinued Operations [Member]. Interest Rate Cap Continuing Operations [Member] Interest Rate Cap Continuing Operations [Member] Interest Rate Cap Continuing Operations [Member]. Interest Rate Cap Discontinued Operations [Member] Interest Rate Cap Discontinued Operations [Member] Interest Rate Cap Discontinued Operations [Member]. Unrealized losses on derivative instruments Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent Goodwill and Intangible Assets Disclosure [Abstract] Beginning balance Amortization Amortization of Intangible Assets Ending balance General and administrative Total operating expenses Costs and Expenses Equity in income/(loss) from subsidiaries Income (Loss) from Equity Method Investments Operating income/(loss) from continuing operations 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 expense Other Nonoperating Income (Expense) Income/(loss) from continuing operations before interest expense, reorganization items, net 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 Loss from continuing operations before reorganization items, net and income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Reorganization items, net Reorganization Items Loss from continuing operations before 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. Income tax benefit Income Tax Expense (Benefit) Net income/(loss) from continuing operations Net change in unrecognized prior service cost Net change in unrecognized actuarial losses Comprehensive income/(loss) Organization, Consolidation and Presentation of Financial Statements [Abstract] Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Current period change excluding amounts reclassified from accumulated other comprehensive loss Other Comprehensive Income (Loss) before Reclassifications, Tax Tax provision Reclassification from AOCI, Current Period, Tax Total change in accumulated other comprehensive loss Other Comprehensive Income (Loss), Tax Related parties Related Party Transactions Disclosure [Text Block] 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] 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 B Warrant [Member] Class B Warrant [Member] Common Class B [Member] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Excluded Litigation Case Proskauer [Member] Excluded Litigation Case Proskauer [Member] Excluded Litigation Case Proskauer [Member]. Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] Proskauer Action [Member] Proskauer Action [Member] Proskauer Action [Member] Sec Investigation [Member] 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] Debtor reorganization items, gain (loss) on settlement of other claims, net Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net Net litigation recovery, amount Net Litigation Recovery, Amount Net Litigation Recovery, Amount Litigation recovery percentage Litigation Recovery Percentage Percentage of litigation recovery during the period. Nondebtor reorganization items, net (gain) loss on settlement of other claims Nondebtor Reorganization Items, Net (Gain) Loss on Settlement of Other Claims Payments of dividends Payments of Dividends Debtor reorganization items settlement due to plantiffs Debtor Reorganization Items Settlement Due to Plantiffs Debtor reorganization items, settlement due to plaintiffs. Schedule of weighted average number of shares Schedule of Weighted Average Number of Shares [Table Text Block] Components of calculation of earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Balance of unrecognized tax benefits as of January 1, Unrecognized Tax Benefits Increases for positions taken in prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Decreases for positions taken in prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Balance of unrecognized tax benefits as of December 31, Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Common Stock [Member] Common Stock [Member] Warrants Related to Spinoff [Member] Warrants Related To Spinoff [Member] Warrants Related to Spinoff [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] Employment Letter Agreement [Member] Employment Letter Agreement [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Management Incentive Compensation Plan [Member] Management Incentive Compensation Plan [Member] Non-Employee Director Incentive Compensation Plan [Member] Nonemployee Director Incentive Compensation Plan [Member] Incentive Plans and 2004 Plan [Member] Incentive Plans And Two Thousand And Four Plan [Member] Incentive Plans and 2004 Plan [Member]. Common Class And Common Class B [Member] Common Class And Common Class B [Member] Common Class A and Common Class B [Member]. Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Performance Based Restricted Units [Member] Performance Based Restricted Units [Member] Restricted Stock, Restricted Stock Units and Performance Awards [Member]. Restricted Stock And Restricted Stock Units And Performance Awards [Member] Restricted Stock, Restricted Stock Units and Performance Awards [Member]. Restricted Stock [Member] Restricted Stock [Member] Time Based Restricted Stock [Member] Time Based Restricted Stock [Member] Time Based Restricted Stock [Member]. Employee Stock Option [Member] Employee Stock Option [Member] Restricted Stock Unit Related To Total Shareholder Return [Member] Restricted Stock Unit Related To Total Shareholder Return [Member] Restricted Stock Unit Related To Total Shareholder Return [Member]. Restricted Stock and Restricted Stock Units [Member] Restricted Stock And Restricted Stock Units [Member] Restricted Stock and Restricted Stock Units [Member]. Restricted Stock Unit Related To Return On Invested Capital [Member] Restricted Stock Unit Related To Return On Invested Capital [Member] Restricted Stock Unit related to Return On Invested Capital [Member]. Restricted Stock Unit Related To Return On Invested Captial And Total Shareholder Return [Member] Restricted Stock Unit Related To Return On Invested Captial And Total Shareholder Return [Member] Restricted Stock Unit related to Return on Invested Captial and Total Shareholder Return [Member] Weighted Average [Member] Weighted Average [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Mr. John J. Ray, III [Member] Director One [Member] Director One [Member]. Mr. Alex Greene and Mr. Nick Semaca [Member] Two Directors [Member] Two Directors [Member]. Directors [Member] Director [Member] Management [Member] Management [Member] Certain Employees and Senior Officers [Member] Certain Employees And Senior Officers [Member] Certain Employees and Senior Officers [Member]. Senior Officers [Member] Senior Officers [Member] Former President and Chief Executive Officer and Director [Member] Former President And Chief Executive Officer And Director [Member] Former President and Chief Executive Officer and Director [Member]. Former Senior Vice President and Chief Financial Office [Member] Former Senior Vice President And Chief Financial Office [Member] Former Senior Vice President and Chief Financial Office [Member]. Former President US Flag Operatons [Member] Former President United States Flag Operatons [Member] Former President United States Flag Operatons [Member]. Supplier [Axis] Supplier [Axis] Share-based Goods and Nonemployee Services Transaction, Supplier [Domain] Share-based Goods and Nonemployee Services Transaction, Supplier [Domain] Messrs. Greene and Semaca Quarterly Fee [Member] Two Consultants [Member] Two Consultants [Member]. Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Post Adjustment Range $2.85 and $3.20 [Member] Range One [Member] Range One [Member]. Class A Warrant [Member] Class Warrant [Member] Class A Warrant Repurchase Average $11.31 [Member] Class Warrant Repurchase Average Eleven Dollars And Thirty One [Member] Class A Warrant Repurchase Average Eleven Dollars and Thirty One [Member]. Class A Warrant Repurchase Average $16.25 [Member] Class Warrant Repurchase Average Sixteen Dollars And Twenty Five [Member] Class A Warrant Repurchase Average Sixteen Dollars and Twenty Five [Member]. Vesting [Axis] Vesting [Axis] Vesting [Domain] Vesting [Domain] Share-based Compensation Award, Tranche One [Member] Share-based Compensation Award, Tranche One [Member] Vesting subject to OSG’s return on invested capital (“ROIC”) performance Share-based Compensation Award, Tranche Two [Member] Vesting subject to OSG’s three-year total stockholder return (“TSR”) performance relative to that of a performance peer group Share-based Compensation Award, Tranche Three [Member] Vesting subject to OSG’s three-year earnings per share (“EPS”) performance in the three-year EPS performance period relative to a compounded annual growth rate Share-based Compensation Award, Tranche Four [Member] Share-based Compensation Award, Tranche Four [Member] Vesting subject to OSG’s ROIC performance in the three-year ROIC performance period Share-based Compensation Award, Tranche Five [Member] Share-based Compensation Award, Tranche Five [Member] Vesting subject to OSG’s TSR performance relative to that of a performance peer group Share-based Compensation Award, Tranche Six [Member] Share-based Compensation Award, Tranche Six [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Stock split, conversion ratio Stockholders' Equity Note, Stock Split, Conversion Ratio Warrants outstanding Class of Warrant or Right, Outstanding Number of securities callable Class of Warrant or Right, Number of Securities Called by Warrants or Rights The additional shares of common stock, per share exercised Additional Shares Of Common Stock Per Share Exercised The additional shares of common stock, per share exercised for holders of warrants. Class of warrant right, number of securities called by each warrant or right Class of Warrant or Right, Number of Securities Called by Each Warrant or Right Shares received pursuant to spinoff Shares Received Pursuant to Spinoff Shares Received Pursuant to Spinoff. Percentage threshold set by board of directors for the entity for U.S. citizen ownerhip of outstanding stock Percentage Threshold Set By Board Of Directors For United States Citizen Ownerhip Of Outstanding Stock Percentage threshold set by board of directors fo the entity for U.S. citizen ownerhip of outstanding stock. Dividends payable, amount per share (USD per share) Dividends Payable, Amount Per Share Share ratio issued as dividend Share ratio issued as dividend Share ratio issued as dividend. Shares repurchased to cover employees tax withholding other than options, shares Shares Repurchased to Cover Employees Tax Withholding Other Than Options Shares repurchased to cover employees tax withholding other than options. Shares repurchased to cover employees tax withholding other than options, price per share Shares Repurchased to Cover Employees Tax Withholding Other Than Options Price Per Share Shares repurchased to cover employees tax withholding other than options, price per Share. Stock repurchased during period, shares Stock Repurchased During Period, Shares Stock repurchase during period, per share amount (USD per share) Stock Repurchaed During Period Per Share Amount Stock repurchaed during period, per share amount. Stock repurchased during period, value Stock Repurchased During Period, Value Stock issued during period, shares, conversion of convertible securities Stock Issued During Period, Shares, Conversion of Convertible Securities Options exercised in period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Additional grants issued in period Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Additional Grants In Period Share based compensation arrangement by share based payment award equity instruments other than options additional grants in period. Shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Granted Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Granted, 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 Vested or expected to vest, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Forfeited Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Restricted stock or unit expense Restricted Stock or Unit Expense Professional fees Professional Fees Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Granted, options Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Grants in period, weighted average grant date fair value (USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Share-based compensation arrangement, award vesting rights percentage Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Number of additional shares authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Threshold goal for compensation expense achievement percentage Compensation Expense Recognized Percentage Target Achievement Level Threshold Compensation expense recognized percentage target achievement level threshold. Exercise price range, options outstanding, weighted average exercise price (USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Lower range, price (USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Upper range, price (USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Grants, options, per share Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Fair value assumptions, risk free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Fair value assumptions, expected dividend rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Fair value assumptions, price volatility factors Share Based Compensation Arrangement by Share Based Payment Award Fair Value Assumptions Expected Volatility Factors Share based compensation arrangement by share based payment award, fair value assumptions, expected volatility factors. Fair value assumptions, expected life Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Accelerated compensation cost Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost Severance costs Severance Costs Increase in shares due to spinoff Increase Decrease in Shares Due to Spinoff Increase (decrease) in shares due to spinoff. Cancelled, other than options Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other Than Options, Cancelled in Period The number of equity-based payment instruments, excluding stock (or unit) options, that were cancelled during the reporting period. Cancelled, options Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Compensation relating to restricted stock/stock unit and stock option grants Share-based Compensation Options outstanding, weighted average remaining term Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Stock options, compensation expense (income) Stock Options, Compensation Expense Income Represents the amount of compensation expense (income) related to stock option grants. Share based compensation expense, unrecognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Nonvested awards, compensation cost not yet recognized, period for recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Restricted stock and restricted stock units [Member] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Nonvested Shares Outstanding Beginning Balance Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Performance awards Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Increase In Performance Award Vesting Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Increase In Performance Award Vesting INSW Spin off modification Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Spin off Modification Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Spin off Modification Cancellations related to INSW Spin-off Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Spin Off Cancellations Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Spin Off Cancellations Nonvested Shares Outstanding Ending Balance Forfeited price range, lower limit (Used Per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Forfeited Price Range, Lower Range Limit Share-based Compensation, Shares Authorized under Stock Option Plans, Forfeited Price Range, Lower Range Limit Forfeited price range, upper limit (USD per share) Share-based Compensation, Shares Authorized under Stock Option Plans, Forfeited Price Range, Upper Range Limit Share-based Compensation, Shares Authorized under Stock Option Plans, Forfeited Price Range, Upper Range Limit Fair Value Disclosures [Abstract] Fair value, by balance sheet grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of cash flow hedges included in accumulated other comprehensive income (loss) Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Contingencies Commitments and Contingencies Disclosure [Text Block] Projected benefit obligation Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Projected Benefit Obligation Accumulated benefit obligation Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation Fair value of plan assets Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets Unrecognized prior service credits Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax Unrecognized prior service credits, net of tax Defined Benefit Plan, Accumulated Other Comprehensive Income Net Prior Service Cost (Credit), after Tax Unrecognized actuarial losses Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax Unrecognized actuarial losses, net of tax Defined Benefit Plan, Accumulated Other Comprehensive Income Net Gains (Losses), after Tax Prior service credit expected to be recognized, next fiscal year Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit) Prior service credit expected to be recognized, next fiscal year, net of tax Defined Benefit Plan Future Amortization Of Prior Service Cost Credit Net Of Tax Defined benefit plan future amortization of prior service cost (credit) net of tax. Actuarial losses expected to be recognized, next fiscal year Defined Benefit Plan, Future Amortization of Gain (Loss) Actuarial losses expected to be recognized, next fiscal year, net of tax Defined Benefit Plan Future Amortization Of Gain Loss Net Of Tax Defined benefit plan future amortization of gain (loss) net of tax. Schedule of Indefinite-Lived Intangible Assets Schedule of Indefinite-Lived Intangible Assets [Table Text Block] London Interbank Offered Rate (LIBOR) [Member] London Interbank Offered Rate (LIBOR) [Member] Margin [Axis] Margin [Axis] Margin [Domain] Margin [Domain] Floor [Member] Floor [Member] Applicable Margin [Member] Applicable Margin [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] 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] Reported Value Measurement Reported Value Measurement [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair value, measurements, nonrecurring [Member] Fair Value, Measurements, Nonrecurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Assets, fair value disclosure Assets, Fair Value Disclosure Loans payable, fair value disclosure Loans Payable, Fair Value Disclosure Notes payable, fair value disclosure Notes Payable, Fair Value Disclosure Financial and nonfinancial liabilities, fair value disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Restricted cash and cash equivalents Restricted Cash and Cash Equivalents Notes, Term Loans and Election Notes [Member] Notes And Term Loans And Election Notes [Member] Notes and Term Loans and Election Notes [Member]. Less current portion Long-term portion Debt, weighted average interest rate Debt, Weighted Average Interest Rate Fair value of financial instruments, derivatives and fair value disclosures Fair Value Disclosures [Text Block] Restructuring and Related Activities [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Employment Letter Agreemen Lump Sum Payment [Member] Employment Letter Agreemen Lump Sum Payment [Member] Employment Letter Agreemen Lump Sum Payment [Member] Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis] Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain] Deferred Bonus [Member] Deferred Bonus [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Deferred compensation, liability Deferred Compensation Cash-based Arrangements, Liability, Current and Noncurrent Payments for Restructuring Payments for Restructuring Schedule of Reorganization Items Net Schedule of Reorganization Items Net [Table Text Block] Tabular disclosure related to reorganization items. Net Cash Provided by (Used in) Operating Activities [Abstract] Net Cash Provided by (Used in) Operating Activities [Abstract] Net cash (used in)/provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net Cash Provided by (Used in) Investing Activities [Abstract] Net Cash Provided by (Used in) Investing Activities [Abstract] Change in restricted cash Increase (Decrease) in Restricted Cash Contributions to subsidiaries Payments for Advance to Affiliate Distributions from subsidiaries Net cash provided by/(used in) investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net Cash Provided by (Used in) Financing Activities [Abstract] 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 Repurchases of common stock and common stock warrants Payments for Repurchase of Warrants Cash dividends paid Payments of Ordinary Dividends, Common Stock 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, Continuing Operations Net (decrease)/increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents Transition Services Agreement [Member] Transition Services Agreement [Member] Transition Services Agreement [Member]. Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Financial Guarantee [Member] Financial Guarantee [Member] Due from related parties, noncurrent Accounts receivable, related parties, current Accounts Receivable, Related Parties, Current Due to related parties, noncurrent Due to Related Parties, Noncurrent Accounts payable, related parties, current Accounts Payable, Related Parties, Current Proceeds from reimbursable agreements to related party Proceeds from Reimbursable Agreements to Related Party Proceeds from reimbursable agreements to related party. Annual fee from related party Annual Fee for Related Party Annual Fee for Related Party. Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Items included in net income/(loss) from continuing operations 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 Vessel impairment charges Impairment of Long-Lived Assets Held-for-use Amortization of debt discount and other deferred financing costs Amortization of Debt Issuance Costs and Discounts Compensation relating to restricted stock, stock unit and stock option grants Deferred income tax benefit Deferred Income Tax Expense (Benefit) Undistributed earnings of affiliated companies Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Deferred payment obligations on charters-in Amortization of Other Deferred Charges Reorganization items, non-cash Reorganization Items Noncash Amount represents the non-cash portion of reorganization items. Other – net Other Noncash Income (Expense) Items included in net income/(loss) related to investing and financing activities: Investing and Financing Activities Items Included In Net Income Loss [Abstract] Loss on repurchases and extinguishment of debt Discount Premium On Repurchase of Debt Discount premium on repurchase of debt. Loss on disposal of vessels and other property, net Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Distributions from INSW Payments for drydocking Payments For Drydocking Amounts paid for drydock costs performed pursuant to regulatory requirements. SEC payment, bankruptcy and IRS claim payments Bankruptcy and IRS Claims Amount Paid Amount paid to settle bankruptcy and IRS claim. Deferred financing costs paid for loan modification Payment Of Deferred Financing Costs Related To Loan Modifications Payment of deferred financing costs related to loan modifications. Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] (Increase)/decrease in receivables Increase (Decrease) in Receivables (Increase)/decrease in income tax recoverable Increase (Decrease) in Income Taxes Receivable (Decrease)/increase in deferred revenue Increase (Decrease) in Deferred Revenue Net change in prepaid items and accounts payable, accrued expenses and other current and long-term liabilities Increase (Decrease) in Operating Liabilities Net cash provided by operating activities Cash Flows from Investing Activities: Change in restricted cash Expenditures for other property Payments to Acquire Other Property, Plant, and Equipment Proceeds from disposal of vessels and other property Proceeds From Disposal Of Vessel And Other Proceeds From Disposal Of Vessel And Other Other – net Payments for (Proceeds from) Other Investing Activities Cash Flows from Financing Activities: Cash dividends paid Payments on debt, including adequate protection payments Repurchases and extinguishment of debt Repurchases of common stock and common stock warrants Tax withholding on share-based awards Net cash used in financing activities Net decrease in cash and cash equivalents Cash and cash equivalents at beginning of year Cash and cash equivalents at end of year Net Cash Provided by (Used in) Discontinued Operations [Abstract] Net Cash Provided by (Used in) Discontinued Operations [Abstract] Cash flows provided by operating activities Cash Provided by (Used in) Operating Activities, Discontinued Operations Cash flows provided by investing activities Cash Provided by (Used in) Investing Activities, Discontinued Operations Cash flows used in financing activities Cash Provided by (Used in) Financing Activities, Discontinued Operations Net (decrease)/increase in cash and cash equivalents from discontinued operations Net Cash Provided by (Used in) Discontinued Operations Statement of Stockholders' Equity [Abstract] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Retained Earnings / (Accumulated Deficit) [Member] Retained Earnings [Member] Accumulated Other Comprehensive Loss [Member] Common Class And Class B [Member] Common Class And Class B [Member] Other comprehensive income (loss) Stock dividends declared Stock Issued During Period, Value, Stock Dividend Issuance and vesting of restricted stock awards Stock Issued During Period, Value, Share-based Compensation, Forfeited Forfeitures and cancellation of restricted stock awards Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Compensation related to Class A options granted, net of forfeitures Stock Granted, Value, Share-based Compensation, Net of Forfeitures Amortization of restricted stock awards Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Amortization Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Amortization Compensation related to Class A restricted stock awards Adjustments to Additional Paid in Capital, Share-based Compensation, Restricted Stock Unit or Restricted Stock Award, Requisite Service Period Recognition Repurchase of Class A warrants Stock Compensation Restricted Stock Stock compensation restricted stock. Conversion of Class A and Class B warrants to common stock Stock Issued During Period, Value, Conversion of Units Stock dividends declared and paid Adjustments to Additional Paid in Capital, Dividends in Excess of Retained Earnings Vesting of restricted stock awards to be settled in cash Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Settled In Cash Stock Issued During Period, Value, Restricted Stock Award, Forfeitures Settled In Cash Compensation related to Class A restricted stock awards, net of forfeitures Adjustments to Additional Paid in Capital, Share-based Compensation, Stock Options, Requisite Service Period Recognition Repurchase of Class A warrants and Class A common stock Reverse stock split Stock Issued During Period, Value, Reverse Stock Splits Stock Issued During Period, Value, Reverse Stock Splits Distribution of INSW stock Stock Issued During Period, Value, Other Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Unsecured Senior Notes [Member] Unsecured Senior Notes [Member] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Bareboat Charters-In [Member] Bareboat Charters In [Member] Bareboat Charters-In [Member]. New ATBs [Member] New Articulated Tug Barges [Member] New Articulated Tug Barges [Member]. Drydock [Member] Drydock [Member] Drydock [Member]. Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Property, plant and equipment, useful life Property, Plant and Equipment, Useful Life Interest costs capitalized Interest Costs Capitalized Amortization period for deferred costs Amortization Period For Deferred Costs Amortization period for deferred costs. Debt Instrument, unamortized discount Debt Instrument, Unamortized Discount Amortization of debt issuance costs Amortization of Debt Issuance Costs Allowance for doubtful accounts receivable Allowance for Doubtful Accounts Receivable Operating leases, future minimum payments due Operating Leases, Future Minimum Payments Due Intercompany payables Unrealized losses on derivative instruments, substantially entered into by the Company's equity method joint venture investees 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), Pension and Other Postretirement Benefit Plans, Net of Tax Accumulated other comprehensive loss Leases [Abstract] Leases [Table] Leases [Table] Schedule that describes and identifies leases. Charters-Out [Member] Charters Out [Member] Charters Out [Member]. Office Space [Member] Building [Member] Contract of Affreightmen [Member] Contract Of Affreightmen [Member] Contract of Affreightmen. 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. Operating leases, future minimum payments receivable, current Operating Leases, Future Minimum Payments Receivable, Current Operating leases, future minimum payments receivable, in two years Operating Leases, Future Minimum Payments Receivable, in Two Years Operating leases, future minimum payments receivable, in three years Operating Leases, Future Minimum Payments Receivable, in Three Years Operating leases, rent expense Operating Leases, Rent Expense DISCONTINUED OPERATIONS Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Income Statement [Abstract] Common Class B and Common Stock [Member] Common Class B And Common Stock [Member] Common Class B and Common Stock [Member]. Shipping Revenues: Revenues [Abstract] Time charter revenues Operating Leases, Income Statement, Lease Revenue Voyage charter revenues Cargo and Freight Revenue Shipping revenues 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 Severance costs Loss on disposal of vessels and other property, including impairments Gain (Loss) on Sale of Assets and Asset Impairment Charges Total operating expenses Income/(loss) from vessel operations Operating Income (Loss) Equity in income of affiliated companies Operating income/(loss) Other expense Income/(loss) before interest expense, reorganization items and income taxes Interest expense Reorganization items, net Income tax benefit from continuing operations Weighted Average Number of Common Shares Outstanding: Weighted average common shares outstanding, basic Per Share Amounts: Basic and Diluted net income/(loss) per share, continuing operations Income (Loss) from Continuing Operations, Per Basic and Diluted Share Basic and Diluted net income/(loss) per share, discontinued operations Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic and Diluted Share Basic and diluted net income/(loss) Earnings Per Share, Basic and Diluted Statement of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Schedule of Property Property, Plant and Equipment [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification out of Accumulated Other Comprehensive Income [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap Entered Into By Joint Ventures Investees [Member] Interest Rate Swap Entered Into By Joint Ventures Investees [Member] Interest Rate Swap Entered Into By Joint Ventures Investees [Member] Interest Rate Cap Entered Into By Subsidiaries [Member] Interest Rate Cap Entered Into By Subsidiaries [Member] Interest Rate Cap Entered Into By Subsidiaries [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Shore Based Employees [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Shore Based Employees [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Shore Based Employees [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Seagoing Employees [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Seagoing Employees [Member] Accumulated Defined Benefit Plans Adjustment Attributable To Parent For Seagoing Employees [Member] Total before tax Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax Total net of tax Equity Method Investments Summarized Balance Sheet Information Equity Method Investments Summarized Balance Sheet Information [Table Text Block] Tabular disclosure of equity method investments summarized balance sheet information. Results of operations of equity method investments Equity Method Investments [Table Text Block] ASSETS Current Assets: Restricted cash Income taxes recoverable Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Investments in subsidiaries Intercompany receivables Accounts Receivable, Related Parties, Noncurrent Other assets Receivable from INSW Due from Affiliate, Noncurrent Current Liabilities: Accounts payable, accrued expenses and other current liabilities Taxes payable, current Reserve for uncertain tax positions Deferred income taxes Common stock - Class A ($0.01 par value; 166,666,666 shares authorized; 78,277,669 and 70,271,172 shares issued and outstanding) Paid-in additional capital Accumulated deficit Accumulated other comprehensive loss Spinoff Termination Benefits [Member] Spinoff Termination Benefits [Member] Spinoff Termination Benefits [Member]. Spinoff Share Based Expense [Member] Spinoff Share Based Expense [Member] Spinoff Share Based Expense [Member]. Severance Reserve Outsourcing RIF [Member] Severance Reserve Outsourcing Rif [Member] Employee Severance [Member] Employee Severance [Member] Severance Reserve Outsourcing [Member] Severance Reserve Outsourcing [Member] Severance Reserve Outsourcing[Member] Severance costs Activity for the year ended December 31 Restructuring Reserve [Roll Forward] Beginning balance Restructuring Reserve Provision Restructuring Charges Utilized Ending balance Equity Method Investments Equity Method Investments and Joint Ventures Disclosure [Text Block] Loss Contingencies [Table] Loss Contingencies [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Independent Registered Public Accounting Firm [Member] Independent Registered Public Accounting Firm [Member] Independent Registered Public Accounting Firm [Member] Former Officers And Directors [Member] Former Officers And Directors [Member] Former Officers and Directors [Member]