$INSW
International Seaways, Inc. Stock $insw

$insw Overview Financials Valuation SEC Filings Company Website

2024 Q1 Form 10-K Financial Statement

#000155837024002108 Filed on February 29, 2024

Income Statement

Concept	2024 Q1	2023 Q4	2023
Revenue	$274.4M	$250.7M	$1.072B
YoY Change	-4.43%	-25.85%	23.95%
Cost Of Revenue	$71.09M	$80.25M	$308.8M
YoY Change	1.17%	11.71%	12.85%
Gross Profit	$203.3M	$170.5M	$762.9M
YoY Change	-6.25%	-35.98%	29.09%
Gross Profit Margin	74.09%	67.99%	71.19%
Selling, General & Admin	$14.79M	$14.79M	$53.85M
YoY Change	19.65%	-5.96%	-4.63%
% of Gross Profit	7.27%	8.68%	7.06%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$34.15M	$33.68M	$129.0M
YoY Change	15.58%	18.58%	16.89%
% of Gross Profit	16.8%	19.76%	16.91%
Operating Expenses	$48.94M	$48.47M	$182.9M
YoY Change	16.78%	9.83%	9.61%
Operating Profit	$154.4M	$122.0M	$615.4M
YoY Change	-16.66%	-45.09%	39.03%
Interest Expense	$12.89M	-$13.86M	$65.76M
YoY Change	-23.96%	-16.86%	13.93%
% of Operating Profit	8.35%	-11.36%	10.69%
Other Income/Expense, Net	$2.954M	$242.0K	$10.65M
YoY Change	-31.0%	-87.44%	356.78%
Pretax Income	$144.5M	$135.6M	$560.3M
YoY Change	-16.3%	-37.95%	44.42%
Income Tax	$0.00	$3.446M	$3.878M
% Of Pretax Income	0.0%	2.54%	0.69%
Net Earnings	$144.5M	$132.0M	$556.4M
YoY Change	-16.3%	-39.55%	43.45%
Net Earnings / Revenue	52.66%	52.66%	51.92%
Basic Earnings Per Share	$2.95		$11.35
Diluted Earnings Per Share	$2.92	$2.67	$11.25
COMMON SHARES
Basic Shares Outstanding	48.93M	48.91M	48.98M
Diluted Shares Outstanding	49.38M		49.43M

Balance Sheet

Concept	2024 Q1	2023 Q4	2023
SHORT-TERM ASSETS
Cash & Short-Term Investments	$214.5M	$186.8M	$186.8M
YoY Change	-17.88%	-42.31%	-42.31%
Cash & Equivalents	$139.5M	$126.8M	$126.8M
Short-Term Investments	$75.00M	$60.00M	$60.00M
Other Short-Term Assets	$20.14M	$15.42M	$15.42M
YoY Change	-51.0%	-3.5%	-3.5%
Inventory	$593.0K	$1.329M	$1.329M
Prepaid Expenses
Receivables	$243.0M	$247.2M	$247.2M
Other Receivables	$11.89M	$14.30M	$14.30M
Total Short-Term Assets	$490.1M	$465.0M	$465.0M
YoY Change	-12.89%	-27.64%	-27.64%
LONG-TERM ASSETS
Property, Plant & Equipment	$1.891B	$1.914B	$2.017B
YoY Change	6.48%	13.95%	4.94%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$34.00M	$31.75M	$31.75M
YoY Change	-0.23%	-12.81%	-12.81%
Other Assets	$32.36M	$6.571M	$7.724M
YoY Change	242.76%	-28.73%	-44.36%
Total Long-Term Assets	$2.061B	$2.057B	$2.057B
YoY Change	2.61%	4.26%	4.26%
TOTAL ASSETS
Total Short-Term Assets	$490.1M	$465.0M	$465.0M
Total Long-Term Assets	$2.061B	$2.057B	$2.057B
Total Assets	$2.551B	$2.522B	$2.522B
YoY Change	-0.78%	-3.58%	-3.58%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$42.05M	$6.570M	$6.570M
YoY Change	-20.96%	259.8%	259.8%
Accrued Expenses	$10.17M	$10.22M	$47.35M
YoY Change	2264.88%	540.54%	8.38%
Deferred Revenue		$6.244M
YoY Change		110.8%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$127.5M	$127.4M	$127.4M
YoY Change	-18.0%	-21.74%	-37.75%
Total Short-Term Liabilities	$179.8M	$195.6M	$195.6M
YoY Change	-20.98%	-24.02%	-24.02%
LONG-TERM LIABILITIES
Long-Term Debt	$564.2M	$595.2M	$595.2M
YoY Change	-27.4%	-30.83%	-30.83%
Other Long-Term Liabilities	$3.309M	$2.628M	$14.26M
YoY Change	76.29%	40.16%	48.3%
Total Long-Term Liabilities	$567.5M	$597.9M	$609.5M
YoY Change	-27.15%	-30.68%	-29.96%
TOTAL LIABILITIES
Total Short-Term Liabilities	$179.8M	$195.6M	$195.6M
Total Long-Term Liabilities	$567.5M	$597.9M	$609.5M
Total Liabilities	$756.5M	$805.1M	$805.1M
YoY Change	-25.41%	-28.6%	-28.6%
SHAREHOLDERS EQUITY
Retained Earnings	$306.7M	$226.8M
YoY Change	480.08%	-1157.65%
Common Stock	$1.489B	$1.491B
YoY Change	-0.86%	-0.75%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.795B	$1.717B	$1.717B
YoY Change
Total Liabilities & Shareholders Equity	$2.551B	$2.522B	$2.522B
YoY Change	-0.78%	-3.58%	-3.58%

Cashflow Statement

Concept	2024 Q1	2023 Q4	2023
OPERATING ACTIVITIES
Net Income	$144.5M	$132.0M	$556.4M
YoY Change	-16.3%	-39.55%	43.45%
Depreciation, Depletion And Amortization	$34.15M	$33.68M	$129.0M
YoY Change	15.58%	18.58%	16.89%
Cash From Operating Activities	$156.4M	$125.5M	$688.4M
YoY Change	-29.15%	-30.9%	139.19%
INVESTING ACTIVITIES
Capital Expenditures	$27.12M	$13.38M	$206.6M
YoY Change	-59.67%	-52.91%	77.08%
Acquisitions
YoY Change
Other Investing Activities	-$15.78M	$58.66M	$82.36M
YoY Change	216.97%	205.83%	-48.36%
Cash From Investing Activities	-$42.90M	$45.28M	-$124.3M
YoY Change	-40.6%	-590.72%	-390.35%
FINANCING ACTIVITIES
Cash Dividend Paid	$64.70M	$61.16M	$308.2M
YoY Change	-34.18%	11.19%	341.29%
Common Stock Issuance & Retirement, Net			$13.95M
YoY Change			-30.32%
Debt Paid & Issued, Net	$19.54M		$382.1M
YoY Change	-85.79%		-52.17%
Cash From Financing Activities	-100.8M	-183.0M	-681.1M
YoY Change	-53.72%	75.69%	266.61%
NET CHANGE
Cash From Operating Activities	156.4M	125.5M	688.4M
Cash From Investing Activities	-42.90M	45.28M	-124.3M
Cash From Financing Activities	-100.8M	-183.0M	-681.1M
Net Change In Cash	12.74M	-12.22M	-117.0M
YoY Change	-118.41%	-117.91%	-180.78%
FREE CASH FLOW
Cash From Operating Activities	$156.4M	$125.5M	$688.4M
Capital Expenditures	$27.12M	$13.38M	$206.6M
Free Cash Flow	$129.3M	$112.1M	$481.8M
YoY Change	-15.79%	-26.82%	181.55%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value
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CY2023	dei	Document Type DocumentType	10-K
CY2023	dei	Document Annual Report DocumentAnnualReport	true
CY2023	dei	Document Period End Date DocumentPeriodEndDate	2023-12-31
CY2023	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2023	dei	Document Transition Report DocumentTransitionReport	false
CY2023	dei	Entity File Number EntityFileNumber	1-37836-1
CY2023	dei	Entity Registrant Name EntityRegistrantName	INTERNATIONAL SEAWAYS, INC.
CY2023	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	1T
CY2023	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	98-0467117
CY2023	dei	Entity Address Address Line1 EntityAddressAddressLine1	600 Third Avenue
CY2023	dei	Entity Address Address Line2 EntityAddressAddressLine2	39th Floor
CY2023	dei	Entity Address City Or Town EntityAddressCityOrTown	New York
CY2023	dei	Entity Address State Or Province EntityAddressStateOrProvince	NY
CY2023	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	10016
CY2023	dei	City Area Code CityAreaCode	212
CY2023	dei	Local Phone Number LocalPhoneNumber	578-1600
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CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	23934000
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CY2023	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2023	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2023	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2023	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2023	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
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CY2023	dei	Auditor Name AuditorName	Ernst & Young LLP
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CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1063000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	6964000
CY2023Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1716757000
CY2022Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1487752000
CY2023Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2521819000
CY2022Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	2615334000
CY2023	insw	Equity Method Investment Summarized Financial Information Shipping Pool Revenue EquityMethodInvestmentSummarizedFinancialInformationShippingPoolRevenue	313873000
CY2022	insw	Equity Method Investment Summarized Financial Information Shipping Pool Revenue EquityMethodInvestmentSummarizedFinancialInformationShippingPoolRevenue	210409000
CY2021	insw	Equity Method Investment Summarized Financial Information Shipping Pool Revenue EquityMethodInvestmentSummarizedFinancialInformationShippingPoolRevenue	72557000
CY2023	us-gaap	Revenues Revenues	1071775000
CY2022	us-gaap	Revenues Revenues	864665000
CY2021	us-gaap	Revenues Revenues	272546000
CY2023	insw	Voyage Expenses VoyageExpenses	16256000
CY2022	insw	Voyage Expenses VoyageExpenses	10955000
CY2021	insw	Voyage Expenses VoyageExpenses	16686000
CY2023	insw	Vessel Expenses VesselExpenses	259539000
CY2022	insw	Vessel Expenses VesselExpenses	240674000
CY2021	insw	Vessel Expenses VesselExpenses	183057000
CY2023	us-gaap	Operating Lease Cost OperatingLeaseCost	39404000
CY2022	us-gaap	Operating Lease Cost OperatingLeaseCost	32132000
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	23934000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	129038000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	110388000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	86674000
CY2023	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	47473000
CY2022	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	46351000
CY2021	us-gaap	General And Administrative Expense GeneralAndAdministrativeExpense	33235000
CY2023	us-gaap	Recapitalization Costs RecapitalizationCosts	568000
CY2022	us-gaap	Recapitalization Costs RecapitalizationCosts	1158000
CY2021	us-gaap	Recapitalization Costs RecapitalizationCosts	110000
CY2021	insw	Asset Acquisition Transaction Cost AssetAcquisitionTransactionCost	50740000
CY2023	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	35934000
CY2022	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	19647000
CY2021	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	9753000
CY2023	us-gaap	Costs And Expenses CostsAndExpenses	456344000
CY2022	us-gaap	Costs And Expenses CostsAndExpenses	422011000
CY2021	us-gaap	Costs And Expenses CostsAndExpenses	384683000
CY2023	us-gaap	Operating Income Loss OperatingIncomeLoss	615431000
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	442654000
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	-112137000
CY2022	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	714000
CY2021	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	21838000
CY2022	insw	Operating Income Loss Including Equity In Income Loss Of Affiliated Companies OperatingIncomeLossIncludingEquityInIncomeLossOfAffiliatedCompanies	443368000
CY2021	insw	Operating Income Loss Including Equity In Income Loss Of Affiliated Companies OperatingIncomeLossIncludingEquityInIncomeLossOfAffiliatedCompanies	-90299000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	10652000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2332000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-5947000
CY2023	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	626083000
CY2022	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	445700000
CY2021	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	-96246000
CY2023	us-gaap	Interest Expense InterestExpense	65759000
CY2022	us-gaap	Interest Expense InterestExpense	57721000
CY2021	us-gaap	Interest Expense InterestExpense	36796000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	560324000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	387979000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-133042000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3878000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	88000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1618000
CY2023	us-gaap	Recapitalization Costs RecapitalizationCosts	568000
CY2022	us-gaap	Recapitalization Costs RecapitalizationCosts	1158000
CY2021	us-gaap	Recapitalization Costs RecapitalizationCosts	110000
CY2021	insw	Asset Acquisition Transaction Cost AssetAcquisitionTransactionCost	50740000
CY2023	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	35934000
CY2023	us-gaap	Costs And Expenses CostsAndExpenses	456344000
CY2022	us-gaap	Costs And Expenses CostsAndExpenses	422011000
CY2021	us-gaap	Costs And Expenses CostsAndExpenses	384683000
CY2023	us-gaap	Operating Income Loss OperatingIncomeLoss	615431000
CY2022	us-gaap	Operating Income Loss OperatingIncomeLoss	442654000
CY2021	us-gaap	Operating Income Loss OperatingIncomeLoss	-112137000
CY2022	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	714000
CY2021	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	21838000
CY2023	insw	Operating Income Loss Including Equity In Income Loss Of Affiliated Companies OperatingIncomeLossIncludingEquityInIncomeLossOfAffiliatedCompanies	615431000
CY2022	insw	Operating Income Loss Including Equity In Income Loss Of Affiliated Companies OperatingIncomeLossIncludingEquityInIncomeLossOfAffiliatedCompanies	443368000
CY2021	insw	Operating Income Loss Including Equity In Income Loss Of Affiliated Companies OperatingIncomeLossIncludingEquityInIncomeLossOfAffiliatedCompanies	-90299000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	10652000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2332000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-5947000
CY2023	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	626083000
CY2022	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	445700000
CY2021	insw	Loss Before Interest Expense Reorganization Items And Taxes LossBeforeInterestExpenseReorganizationItemsAndTaxes	-96246000
CY2023	us-gaap	Interest Expense InterestExpense	65759000
CY2022	us-gaap	Interest Expense InterestExpense	57721000
CY2021	us-gaap	Interest Expense InterestExpense	36796000
CY2023	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	560324000
CY2022	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	387979000
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-133042000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3878000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	88000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1618000
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-1168000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	556446000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	387891000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-133492000
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	48978452
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	49381459
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	38407007
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49428967
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49844904
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	38407007
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.35
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.85
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-3.48
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.25
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2021	us-gaap	Net Income Loss Attributable To Noncontrolling Interest NetIncomeLossAttributableToNoncontrollingInterest	-1168000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	556446000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	387891000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-133492000
CY2023	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	48978452
CY2022	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	49381459
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	38407007
CY2023	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49428967
CY2022	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	49844904
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	38407007
CY2023	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.35
CY2022	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	7.85
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-3.48
CY2023	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.25
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.77
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-3.48
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2023	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	-7563000
CY2022	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	21775000
CY2021	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	19235000
CY2023	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	59000
CY2022	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	335000
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	-54000
CY2023	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-405000
CY2022	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-2116000
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	964000
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8027000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19324000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20253000
CY2023	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	548419000
CY2022	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	407215000
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-114407000
CY2021	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-1168000
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	548419000
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	407215000
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-113239000
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	129038000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	110388000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	86674000
CY2022	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	1697000
CY2022	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	7.77
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-3.48
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2023	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	-7563000
CY2022	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	21775000
CY2021	us-gaap	Change In Unrealized Gain Loss On Fair Value Hedging Instruments1 ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1	19235000
CY2023	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	59000
CY2022	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	335000
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plan Net Prior Service Costs Credit Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax	-54000
CY2023	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-405000
CY2022	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-2116000
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	964000
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8027000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19324000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20253000
CY2023	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	548419000
CY2022	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	407215000
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-114407000
CY2021	us-gaap	Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxAttributableToNoncontrollingInterest	-1168000
CY2023	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	548419000
CY2022	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	407215000
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-113239000
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	129038000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	110388000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	86674000
CY2022	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	1697000
CY2021	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	3497000
CY2023	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	5623000
CY2022	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	5224000
CY2021	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	2313000
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	842000
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2428000
CY2023	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	2686000
CY2022	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	1266000
CY2021	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	2113000
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	8518000
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	6746000
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	10529000
CY2023	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-20000
CY2022	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	10297000
CY2021	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	21838000
CY2021	us-gaap	Noncash Merger Related Costs NoncashMergerRelatedCosts	31053000
CY2023	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2562000
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2242000
CY2021	us-gaap	Impairment Of Long Lived Assets Held For Use ImpairmentOfLongLivedAssetsHeldForUse	3497000
CY2023	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	5623000
CY2022	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	5224000
CY2021	us-gaap	Amortization Of Financing Costs And Discounts AmortizationOfFinancingCostsAndDiscounts	2313000
CY2022	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	842000
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	2428000
CY2023	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	2686000
CY2022	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	1266000
CY2021	insw	Deferred Financing Costs Write Off DeferredFinancingCostsWriteOff	2113000
CY2023	us-gaap	Share Based Compensation ShareBasedCompensation	8518000
CY2022	us-gaap	Share Based Compensation ShareBasedCompensation	6746000
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	10529000
CY2023	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-20000
CY2022	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	10297000
CY2021	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	21838000
CY2021	us-gaap	Noncash Merger Related Costs NoncashMergerRelatedCosts	31053000
CY2023	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2562000
CY2022	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	2242000
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-2969000
CY2023	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	35934000
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	21344000
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	13250000
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-1323000
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-4465000
CY2022	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	-9513000
CY2022	insw	Allocated General And Administrative Expenses Recorded As Capital Contributions AllocatedGeneralAndAdministrativeExpensesRecordedAsCapitalContributions	3111000
CY2021	insw	Allocated General And Administrative Expenses Recorded As Capital Contributions AllocatedGeneralAndAdministrativeExpensesRecordedAsCapitalContributions	9835000
CY2023	insw	Payments For Drydocking PaymentsForDrydocking	34539000
CY2022	insw	Payments For Drydocking PaymentsForDrydocking	43327000
CY2021	insw	Payments For Drydocking PaymentsForDrydocking	42416000
CY2023	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	3156000
CY2022	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	5301000
CY2021	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	1846000
CY2023	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-42610000
CY2022	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	182679000
CY2021	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	16470000
CY2023	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	3283000
CY2022	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	2609000
CY2021	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	-1636000
CY2023	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	8734000
CY2022	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	13102000
CY2021	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	-3644000
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	688402000
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	287801000
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-76192000
CY2021	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	54047000
CY2023	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	205159000
CY2022	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	115976000
CY2021	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	-2969000
CY2023	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	35934000
CY2022	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	21344000
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	13250000
CY2023	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-1323000
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-4465000
CY2022	us-gaap	Equity Method Investment Realized Gain Loss On Disposal EquityMethodInvestmentRealizedGainLossOnDisposal	-9513000
CY2022	insw	Allocated General And Administrative Expenses Recorded As Capital Contributions AllocatedGeneralAndAdministrativeExpensesRecordedAsCapitalContributions	3111000
CY2021	insw	Allocated General And Administrative Expenses Recorded As Capital Contributions AllocatedGeneralAndAdministrativeExpensesRecordedAsCapitalContributions	9835000
CY2023	insw	Payments For Drydocking PaymentsForDrydocking	34539000
CY2022	insw	Payments For Drydocking PaymentsForDrydocking	43327000
CY2021	insw	Payments For Drydocking PaymentsForDrydocking	42416000
CY2023	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	3156000
CY2022	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	5301000
CY2021	us-gaap	Proceeds From Insurance Settlement Operating Activities ProceedsFromInsuranceSettlementOperatingActivities	1846000
CY2023	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-42610000
CY2022	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	182679000
CY2021	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	16470000
CY2023	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	3283000
CY2022	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	2609000
CY2021	us-gaap	Increase Decrease In Deferred Revenue IncreaseDecreaseInDeferredRevenue	-1636000
CY2023	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	8734000
CY2022	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	13102000
CY2021	us-gaap	Increase Decrease In Operating Liabilities IncreaseDecreaseInOperatingLiabilities	-3644000
CY2023	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	688402000
CY2022	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	287801000
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-76192000
CY2021	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	54047000
CY2023	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	205159000
CY2022	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	115976000
CY2021	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	78035000
CY2023	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	66002000
CY2022	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	99157000
CY2021	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	165809000
CY2023	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	1471000
CY2022	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	710000
CY2021	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	979000
CY2023	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	-3639000
CY2022	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	1362000
CY2021	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	-7554000
CY2022	us-gaap	Proceeds From Sale Of Equity Method Investments ProceedsFromSaleOfEquityMethodInvestments	138966000
CY2023	us-gaap	Payments To Acquire Restricted Certificates Of Deposit PaymentsToAcquireRestrictedCertificatesOfDeposit	235000000
CY2022	us-gaap	Payments To Acquire Restricted Certificates Of Deposit PaymentsToAcquireRestrictedCertificatesOfDeposit	105000000
CY2023	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	255000000
CY2022	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	25000000
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-124267000
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	42799000
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	133288000
CY2021	insw	Payment To Acquire Vessels And Vessels Improvements PaymentToAcquireVesselsAndVesselsImprovements	78035000
CY2023	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	66002000
CY2022	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	99157000
CY2021	insw	Proceeds From Costs Sale Of Property Plant And Equipment ProceedsFromCostsSaleOfPropertyPlantAndEquipment	165809000
CY2023	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	1471000
CY2022	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	710000
CY2021	us-gaap	Payments To Acquire Other Property Plant And Equipment PaymentsToAcquireOtherPropertyPlantAndEquipment	979000
CY2023	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	-3639000
CY2022	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	1362000
CY2021	insw	Proceeds From Payments To Pool Working Capital Deposits ProceedsFromPaymentsToPoolWorkingCapitalDeposits	-7554000
CY2022	us-gaap	Proceeds From Sale Of Equity Method Investments ProceedsFromSaleOfEquityMethodInvestments	138966000
CY2023	us-gaap	Payments To Acquire Restricted Certificates Of Deposit PaymentsToAcquireRestrictedCertificatesOfDeposit	235000000
CY2022	us-gaap	Payments To Acquire Restricted Certificates Of Deposit PaymentsToAcquireRestrictedCertificatesOfDeposit	105000000
CY2023	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	255000000
CY2022	us-gaap	Proceeds From Sale Of Short Term Investments ProceedsFromSaleOfShortTermInvestments	25000000
CY2023	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-124267000
CY2022	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	42799000
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	133288000
CY2022	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	641050000
CY2021	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	83712000
CY2023	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	50000000
CY2023	insw	Repayments On Revolving Credit Facilities RepaymentsOnRevolvingCreditFacilities	50000000
CY2023	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	382050000
CY2022	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	798740000
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	619273000
CY2023	insw	Payment Of Premiums For Debt Extinguishment PaymentOfPremiumsForDebtExtinguishment	1323000
CY2022	insw	Proceeds From Sale And Leaseback Financing Net Of Issuance And Deferred Financing Costs ProceedsFromSaleAndLeasebackFinancingNetOfIssuanceAndDeferredFinancingCosts	108005000
CY2021	insw	Proceeds From Sale And Leaseback Financing Net Of Issuance And Deferred Financing Costs ProceedsFromSaleAndLeasebackFinancingNetOfIssuanceAndDeferredFinancingCosts	447086000
CY2023	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	135965000
CY2022	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	39240000
CY2021	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	5678000
CY2023	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	3577000
CY2022	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	909000
CY2021	us-gaap	Payments For Hedge Financing Activities PaymentsForHedgeFinancingActivities	15697000
CY2023	us-gaap	Payments Of Dividends PaymentsOfDividends	308154000
CY2022	us-gaap	Payments Of Dividends PaymentsOfDividends	69841000
CY2021	us-gaap	Payments Of Dividends PaymentsOfDividends	40939000
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	13948000
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	20017000
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	16660000
CY2021	us-gaap	Payments To Minority Shareholders PaymentsToMinorityShareholders	5266000
CY2023	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	5819000
CY2022	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	6097000
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1125000
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-681119000
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-185789000
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-173840000
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-116984000
CY2022	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	641050000
CY2021	us-gaap	Proceeds From Issuance Of Other Long Term Debt ProceedsFromIssuanceOfOtherLongTermDebt	83712000
CY2023	us-gaap	Proceeds From Long Term Lines Of Credit ProceedsFromLongTermLinesOfCredit	50000000
CY2023	insw	Repayments On Revolving Credit Facilities RepaymentsOnRevolvingCreditFacilities	50000000
CY2023	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	382050000
CY2022	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	798740000
CY2023	insw	Payment Of Premiums For Debt Extinguishment PaymentOfPremiumsForDebtExtinguishment	1323000
CY2023	insw	Proceeds From Sale And Leaseback Financing Net Of Issuance And Deferred Financing Costs ProceedsFromSaleAndLeasebackFinancingNetOfIssuanceAndDeferredFinancingCosts	169717000
CY2022	insw	Proceeds From Sale And Leaseback Financing Net Of Issuance And Deferred Financing Costs ProceedsFromSaleAndLeasebackFinancingNetOfIssuanceAndDeferredFinancingCosts	108005000
CY2021	insw	Proceeds From Sale And Leaseback Financing Net Of Issuance And Deferred Financing Costs ProceedsFromSaleAndLeasebackFinancingNetOfIssuanceAndDeferredFinancingCosts	447086000
CY2023	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	135965000
CY2022	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	39240000
CY2021	insw	Payments Of Sale And Leaseback Financing PaymentsOfSaleAndLeasebackFinancing	5678000
CY2023	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	3577000
CY2022	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	909000
CY2021	us-gaap	Payments For Hedge Financing Activities PaymentsForHedgeFinancingActivities	15697000
CY2023	us-gaap	Payments Of Dividends PaymentsOfDividends	308154000
CY2022	us-gaap	Payments Of Dividends PaymentsOfDividends	69841000
CY2021	us-gaap	Payments Of Dividends PaymentsOfDividends	40939000
CY2023	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	13948000
CY2022	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	20017000
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	16660000
CY2021	us-gaap	Payments To Minority Shareholders PaymentsToMinorityShareholders	5266000
CY2023	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	5819000
CY2022	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	6097000
CY2021	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	1125000
CY2023	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-681119000
CY2022	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-185789000
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-173840000
CY2023	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-116984000
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	144811000
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-116744000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	243744000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98933000
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	215677000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126760000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	243744000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98933000
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	972042000
CY2021	us-gaap	Noncontrolling Interest Increase From Business Combination NoncontrollingInterestIncreaseFromBusinessCombination	389626000
CY2021Q4	insw	Derecognition Of Noncontrolling Interest Non Cash Activities DerecognitionOfNoncontrollingInterestNonCashActivities	23460000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20253000
CY2021	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	40947000
CY2021	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	5266000
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	1125000
CY2021	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	1245000
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	16660000
CY2022	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	144811000
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-116744000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	243744000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98933000
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	215677000
CY2023Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	126760000
CY2022Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	243744000
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	98933000
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	972042000
CY2021	us-gaap	Noncontrolling Interest Increase From Business Combination NoncontrollingInterestIncreaseFromBusinessCombination	389626000
CY2021Q4	insw	Derecognition Of Noncontrolling Interest Non Cash Activities DerecognitionOfNoncontrollingInterestNonCashActivities	23460000
CY2021	us-gaap	Profit Loss ProfitLoss	-134660000
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	20253000
CY2021	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	40947000
CY2021	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	5266000
CY2021	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	1125000
CY2021	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	1245000
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	16660000
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1170332000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19324000
CY2022	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	69843000
CY2022	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	584000
CY2022	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	988000
CY2022	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	20017000
CY2022Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1487752000
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8027000
CY2023	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	308165000
CY2023	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	5819000
CY2023	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	574000
CY2023	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	13948000
CY2023Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1716757000
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2
CY2021Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	50674393
CY2021Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1170332000
CY2022	us-gaap	Profit Loss ProfitLoss	387891000
CY2022	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	19324000
CY2022	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	69843000
CY2022	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	584000
CY2022	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	988000
CY2022	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	20017000
CY2022Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1487752000
CY2023	us-gaap	Profit Loss ProfitLoss	556446000
CY2023	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-8027000
CY2023	us-gaap	Adjustments To Additional Paid In Capital Dividends In Excess Of Retained Earnings AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings	308165000
CY2023	us-gaap	Stock Issued During Period Value Restricted Stock Award Forfeitures StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures	5819000
CY2023	us-gaap	Stock Granted During Period Value Sharebased Compensation StockGrantedDuringPeriodValueSharebasedCompensation	574000
CY2023	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	13948000
CY2023Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1716757000
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2
CY2021Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	50674393
CY2021Q3	insw	Asset Acquisition Special Dividends AssetAcquisitionSpecialDividends	31500000
CY2021Q3	insw	Asset Acquisition Special Dividends Per Share Costs AssetAcquisitionSpecialDividendsPerShareCosts	1.12
CY2023	insw	Number Of Representatives In Board Of Directors Of Combined Company NumberOfRepresentativesInBoardOfDirectorsOfCombinedCompany	10
CY2023Q4	insw	Number Of Additional Directors Designated By Company NumberOfAdditionalDirectorsDesignatedByCompany	6
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Accelerated Vesting Number SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber	5035
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	261000
CY2023	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	70000
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	191000
CY2021Q3	insw	Asset Acquisition Special Dividends AssetAcquisitionSpecialDividends	31500000
CY2021Q3	insw	Asset Acquisition Special Dividends Per Share Costs AssetAcquisitionSpecialDividendsPerShareCosts	1.12
CY2023	insw	Number Of Representatives In Board Of Directors Of Combined Company NumberOfRepresentativesInBoardOfDirectorsOfCombinedCompany	10
CY2023Q4	insw	Number Of Additional Directors Designated By Company NumberOfAdditionalDirectorsDesignatedByCompany	6
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Accelerated Vesting Number SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber	5035
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2023Q4	insw	Number Of Additional Directors Designated By Counterparty NumberOfAdditionalDirectorsDesignatedByCounterparty	3
CY2021Q3	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	1213000
CY2023Q4	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	0
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;">3.<i style="font-style:italic;"> </i><i style="font-style:italic;">Concentration of credit risk</i> — The Company is subject to concentrations of credit risk principally from cash and cash equivalents and voyage receivables due from charterers and pools in which the Company participates. The Company manages its credit risk exposure through assessment of the creditworthiness of its counterparties. Cash equivalents consist primarily of time deposits, and money market funds. The Company places its cash and cash equivalents in what we believe to be credit-worthy financial institutions. The Company’s money market funds are carried at fair market value. Voyage receivables consist of (i) operating lease receivables associated with revenues from leases accounted for under ASC 842, <i style="font-style:italic;">Leases </i>(ASC 842), which are primarily accrued earnings due from pools; and (ii) billed and unbilled non-operating lease receivables associated with revenues from services accounted for under ASC 606, <i style="font-style:italic;">Revenue from Contracts with Customers</i> (ASC 606), which are due within one year. The </p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">Company performs ongoing evaluations to determine customer credit and limits the amount of credit extended to customers. The Company maintains allowances for estimated credit losses and these losses have generally been within its expectations. </p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;"><span style="visibility:hidden;background:#ffff00;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">With respect to non-operating lease receivables, the Company recognizes as an allowance its estimate of expected credit losses in accordance with ASC 326, <i style="font-style:italic;">Financial Instruments – Credit losses</i> (ASC 326), based on troubled accounts, historical experience, other currently available evidence, and reasonable and supportable forecasts about the future. The Company makes significant judgements and assumptions to estimate its expected losses. The Company makes judgments about the creditworthiness of customers based on ongoing credit evaluations including analysis of the counterparty’s established credit rating or assessment of the counterparty’s creditworthiness based on our analysis of their financial statements when a credit rating is not available, country and political risk of the counterparty, and their business strategy. The Company manages its non-operating lease receivable portfolios using delinquency as a key credit quality indicator. The Company performs the following steps in estimating expected losses: (i) gather historical losses over five years; (ii) assume outstanding billed amounts over 180 days as additional expected losses; and (iii) make forward-looking adjustments to the expected losses to reflect future economic conditions by comparing credit default swap rates of significant customers over time. In addition, the Company performs individual assessments for customers that do not share risk characteristics with other customers (for example a customer under bankruptcy or a customer with known disputes or collectability issues).</p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">The allowance for credit losses reflects our best estimate of probable losses inherent in the voyage receivables balance and is recognized as an allowance or contra-asset to the voyage receivables balance. Provisions for credit losses associated with voyage receivables are included in general and administrative expenses on the consolidated statements of operations. The movement in the allowance for credit losses during the three years ended December 31, 2023 is summarized as follows:</p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;"></span></p><div style="padding-left:18pt;"><table style="border-collapse:collapse;font-size:16pt;height:max-content;padding-left:0pt;padding-right:0pt;width:96.65%;"><tr style="height:1pt;"><td style="vertical-align:bottom;width:80.6%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:16.71%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td></tr><tr><td style="vertical-align:bottom;width:80.6%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><i style="font-style:italic;">(Dollars in thousands)</i></p></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;width:16.71%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt;">Allowance for Credit Losses - Voyage Receivables</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at January 1, 2021</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 55</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Reversal of expected credit losses</p></td><td style="vertical-align:bottom;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (21)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Write-offs charged against the allowance</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (3)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2021</p></td><td style="vertical-align:bottom;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 31</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Provision for expected credit losses</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 230</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2022</p></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 261</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Reversal of expected credit losses</p></td><td style="vertical-align:middle;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (70)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2023</p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;border-bottom:3px double #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">$</p></td><td style="vertical-align:middle;white-space:nowrap;width:16.71%;border-bottom:3px double #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 191</p></td></tr></table></div><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;background:#ffff00;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">During the years ended December 31, 2023, 2022 and 2021, the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted in aggregate for 95% and 96% of consolidated voyage receivables at December 31, 2023 and December 31, 2022, respectively.</p>
CY2023	insw	Credit Losses Historical Period CreditLossesHistoricalPeriod	P5Y
CY2023	insw	Credit Losses Outstanding Additional Period CreditLossesOutstandingAdditionalPeriod	P180D
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	55000
CY2021	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	21000
CY2021	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	3000
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	31000
CY2022	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	-230000
CY2021Q3	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	1213000
CY2022Q4	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	0
CY2023Q4	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	0
CY2023	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;">3.<i style="font-style:italic;"> </i><i style="font-style:italic;">Concentration of credit risk</i> — The Company is subject to concentrations of credit risk principally from cash and cash equivalents and voyage receivables due from charterers and pools in which the Company participates. The Company manages its credit risk exposure through assessment of the creditworthiness of its counterparties. Cash equivalents consist primarily of time deposits, and money market funds. The Company places its cash and cash equivalents in what we believe to be credit-worthy financial institutions. The Company’s money market funds are carried at fair market value. Voyage receivables consist of (i) operating lease receivables associated with revenues from leases accounted for under ASC 842, <i style="font-style:italic;">Leases </i>(ASC 842), which are primarily accrued earnings due from pools; and (ii) billed and unbilled non-operating lease receivables associated with revenues from services accounted for under ASC 606, <i style="font-style:italic;">Revenue from Contracts with Customers</i> (ASC 606), which are due within one year. The </p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">Company performs ongoing evaluations to determine customer credit and limits the amount of credit extended to customers. The Company maintains allowances for estimated credit losses and these losses have generally been within its expectations. </p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;"><span style="visibility:hidden;background:#ffff00;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">With respect to non-operating lease receivables, the Company recognizes as an allowance its estimate of expected credit losses in accordance with ASC 326, <i style="font-style:italic;">Financial Instruments – Credit losses</i> (ASC 326), based on troubled accounts, historical experience, other currently available evidence, and reasonable and supportable forecasts about the future. The Company makes significant judgements and assumptions to estimate its expected losses. The Company makes judgments about the creditworthiness of customers based on ongoing credit evaluations including analysis of the counterparty’s established credit rating or assessment of the counterparty’s creditworthiness based on our analysis of their financial statements when a credit rating is not available, country and political risk of the counterparty, and their business strategy. The Company manages its non-operating lease receivable portfolios using delinquency as a key credit quality indicator. The Company performs the following steps in estimating expected losses: (i) gather historical losses over five years; (ii) assume outstanding billed amounts over 180 days as additional expected losses; and (iii) make forward-looking adjustments to the expected losses to reflect future economic conditions by comparing credit default swap rates of significant customers over time. In addition, the Company performs individual assessments for customers that do not share risk characteristics with other customers (for example a customer under bankruptcy or a customer with known disputes or collectability issues).</p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">The allowance for credit losses reflects our best estimate of probable losses inherent in the voyage receivables balance and is recognized as an allowance or contra-asset to the voyage receivables balance. Provisions for credit losses associated with voyage receivables are included in general and administrative expenses on the consolidated statements of operations. The movement in the allowance for credit losses during the three years ended December 31, 2023 is summarized as follows:</p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;"></span></p><div style="padding-left:18pt;"><table style="border-collapse:collapse;font-size:16pt;height:max-content;padding-left:0pt;padding-right:0pt;width:96.65%;"><tr style="height:1pt;"><td style="vertical-align:bottom;width:80.6%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:16.71%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td></tr><tr><td style="vertical-align:bottom;width:80.6%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><i style="font-style:italic;">(Dollars in thousands)</i></p></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;width:16.71%;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt;">Allowance for Credit Losses - Voyage Receivables</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at January 1, 2021</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 55</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Reversal of expected credit losses</p></td><td style="vertical-align:bottom;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (21)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Write-offs charged against the allowance</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (3)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2021</p></td><td style="vertical-align:bottom;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 31</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Provision for expected credit losses</p></td><td style="vertical-align:bottom;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 230</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2022</p></td><td style="vertical-align:middle;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 261</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 6pt;">Reversal of expected credit losses</p></td><td style="vertical-align:middle;width:1.34%;background:#cceeff;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:16.71%;background:#cceeff;border-bottom:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt;"> (70)</p></td></tr><tr><td style="vertical-align:middle;width:80.6%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">Balance at December 31,2023</p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;white-space:nowrap;width:1.34%;border-bottom:3px double #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;">$</p></td><td style="vertical-align:middle;white-space:nowrap;width:16.71%;border-bottom:3px double #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0pt 0pt;"> 191</p></td></tr></table></div><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;"><span style="margin-left:0pt;visibility:hidden;background:#ffff00;"></span></p><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0pt 18pt;">During the years ended December 31, 2023, 2022 and 2021, the Company did not have any individual customers who accounted for 10% or more of its revenues apart from the pools in which it participates. The pools in which the Company participates accounted in aggregate for 95% and 96% of consolidated voyage receivables at December 31, 2023 and December 31, 2022, respectively.</p>
CY2023	insw	Credit Losses Historical Period CreditLossesHistoricalPeriod	P5Y
CY2023	insw	Credit Losses Outstanding Additional Period CreditLossesOutstandingAdditionalPeriod	P180D
CY2020Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	55000
CY2021	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	21000
CY2021	us-gaap	Allowance For Doubtful Accounts Receivable Write Offs AllowanceForDoubtfulAccountsReceivableWriteOffs	3000
CY2021Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	31000
CY2022	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	-230000
CY2022Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	261000
CY2023	insw	Reversal Provision For Loan And Lease Losses ReversalProvisionForLoanAndLeaseLosses	70000
CY2023Q4	us-gaap	Allowance For Doubtful Accounts Receivable AllowanceForDoubtfulAccountsReceivable	191000
CY2023	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	2400000
CY2022	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	4300000
CY2021	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	600000
CY2023	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	4700000
CY2022	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	4900000
CY2021	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	2200000
CY2023	insw	Collateralized Basis Percentage Benchmark Used In Determining Borrowing Rate CollateralizedBasisPercentageBenchmarkUsedInDeterminingBorrowingRate	1
CY2023	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	2400000
CY2022	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	4300000
CY2021	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	600000
CY2023	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	4700000
CY2022	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	4900000
CY2021	us-gaap	Amortization Of Financing Costs AmortizationOfFinancingCosts	2200000
CY2023	insw	Collateralized Basis Percentage Benchmark Used In Determining Borrowing Rate CollateralizedBasisPercentageBenchmarkUsedInDeterminingBorrowingRate	1
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;">14.<i style="font-style:italic;"> Use of estimates</i> — The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, equity, revenues and expenses reported in the financial statements and accompanying notes. The most significant estimates relate to the depreciation of vessels and other property, amortization of drydocking costs, judgments involved in identifying performance obligations in revenue contracts, estimating the amount of variable consideration to include in the transaction price, and allocating the transaction price to each performance obligation, estimates used in assessing the recoverability of equity method investments and other long-lived assets, liabilities incurred relating to pension benefits, and income taxes. Actual results could differ from those estimates.</p>
CY2023	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;padding-left:18pt;text-indent:-18pt;margin:0pt;">14.<i style="font-style:italic;"> Use of estimates</i> — The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, equity, revenues and expenses reported in the financial statements and accompanying notes. The most significant estimates relate to the depreciation of vessels and other property, amortization of drydocking costs, judgments involved in identifying performance obligations in revenue contracts, estimating the amount of variable consideration to include in the transaction price, and allocating the transaction price to each performance obligation, estimates used in assessing the recoverability of equity method investments and other long-lived assets, liabilities incurred relating to pension benefits, and income taxes. Actual results could differ from those estimates.</p>
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	556043000
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	556043000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	387401000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	387401000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-133645000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-133645000
CY2023	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	403000
CY2022	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Basic ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic	490000
CY2022	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	490000
CY2021	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Basic ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic	153000
CY2021	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	153000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	556446000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	387891000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-133492000
CY2023	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	450515
CY2022	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	463445
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0
CY2023	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	40504
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	86524
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1046088
CY2023	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	2
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1071775000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	129038000
CY2023	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	35934000
CY2023	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	627538000
CY2023Q4	insw	Adjusted Assets AdjustedAssets	2309491000
CY2023	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	205159000
CY2023	insw	Payments For Drydocking PaymentsForDrydocking	34539000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	864665000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	110388000
CY2022	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	19647000
CY2022	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	470516000
CY2022	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	714000
CY2022Q4	insw	Adjusted Assets AdjustedAssets	2262644000
CY2022	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	115976000
CY2022	insw	Payments For Drydocking PaymentsForDrydocking	43327000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	272546000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	86674000
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	556043000
CY2023	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	556043000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	387401000
CY2022	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	387401000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	-133645000
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	-133645000
CY2023	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Basic ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic	403000
CY2023	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	403000
CY2022	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Basic ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic	490000
CY2022	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	490000
CY2021	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Basic ParticipatingSecuritiesDistributedAndUndistributedEarningsLossBasic	153000
CY2021	us-gaap	Participating Securities Distributed And Undistributed Earnings Loss Diluted ParticipatingSecuritiesDistributedAndUndistributedEarningsLossDiluted	153000
CY2023	us-gaap	Net Income Loss NetIncomeLoss	556446000
CY2022	us-gaap	Net Income Loss NetIncomeLoss	387891000
CY2021	us-gaap	Net Income Loss NetIncomeLoss	-133492000
CY2023	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	450515
CY2022	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	463445
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	0
CY2023	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	40504
CY2022	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	86524
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1046088
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1071775000
CY2023	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	129038000
CY2023	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	35934000
CY2023	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	627538000
CY2023Q4	insw	Adjusted Assets AdjustedAssets	2309491000
CY2023	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	205159000
CY2023	insw	Payments For Drydocking PaymentsForDrydocking	34539000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	864665000
CY2022	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	110388000
CY2022	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	19647000
CY2022	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	470516000
CY2022	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	714000
CY2022Q4	insw	Adjusted Assets AdjustedAssets	2262644000
CY2022	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	115976000
CY2022	insw	Payments For Drydocking PaymentsForDrydocking	43327000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	272546000
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	86674000
CY2021	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	9753000
CY2021	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	9753000
CY2021	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	-37805000
CY2021	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	21838000
CY2021Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures Fair Value Disclosure InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVenturesFairValueDisclosure	180331000
CY2021Q4	insw	Adjusted Assets AdjustedAssets	2234245000
CY2021	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	78035000
CY2021	insw	Payments For Drydocking PaymentsForDrydocking	42416000
CY2023	insw	Voyage Expenses VoyageExpenses	16256000
CY2022	insw	Voyage Expenses VoyageExpenses	10955000
CY2021	insw	Voyage Expenses VoyageExpenses	16686000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1071775000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	864665000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	272546000
CY2023Q4	insw	Adjusted Assets AdjustedAssets	2309491000
CY2022Q4	insw	Adjusted Assets AdjustedAssets	2262644000
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	126760000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	243744000
CY2023Q4	us-gaap	Short Term Investments ShortTermInvestments	60000000
CY2022Q4	us-gaap	Short Term Investments ShortTermInvestments	80000000
CY2023Q4	us-gaap	Other Assets OtherAssets	25568000
CY2022Q4	us-gaap	Other Assets OtherAssets	28946000
CY2023Q4	us-gaap	Assets Assets	2521819000
CY2022Q4	us-gaap	Assets Assets	2615334000
CY2021	insw	Operating Income Loss Allocable To Segments OperatingIncomeLossAllocableToSegments	-37805000
CY2021	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	21838000
CY2021Q4	us-gaap	Investments In Affiliates Subsidiaries Associates And Joint Ventures Fair Value Disclosure InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVenturesFairValueDisclosure	180331000
CY2021Q4	insw	Adjusted Assets AdjustedAssets	2234245000
CY2021	us-gaap	Payments For Proceeds From Productive Assets PaymentsForProceedsFromProductiveAssets	78035000
CY2021	insw	Payments For Drydocking PaymentsForDrydocking	42416000
CY2023	insw	Voyage Expenses VoyageExpenses	16256000
CY2022	insw	Voyage Expenses VoyageExpenses	10955000
CY2021	insw	Voyage Expenses VoyageExpenses	16686000
CY2023	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1071775000
CY2022	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	864665000
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	272546000
CY2023Q4	insw	Adjusted Assets AdjustedAssets	2309491000
CY2022Q4	insw	Adjusted Assets AdjustedAssets	2262644000
CY2023Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	126760000
CY2022Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	243744000
CY2023Q4	us-gaap	Short Term Investments ShortTermInvestments	60000000
CY2022Q4	us-gaap	Short Term Investments ShortTermInvestments	80000000
CY2023Q4	us-gaap	Other Assets OtherAssets	25568000
CY2022Q4	us-gaap	Other Assets OtherAssets	28946000
CY2023Q4	us-gaap	Assets Assets	2521819000
CY2022Q4	us-gaap	Assets Assets	2615334000
CY2023Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1996976000
CY2022Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1869561000
CY2021Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1907894000
CY2023	insw	Number Of Vessels Used As Collateral On Debt NumberOfVesselsUsedAsCollateralOnDebt	42
CY2022Q1	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	3000000.0
CY2022Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	65611000
CY2021Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	55753000
CY2020Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	36334000
CY2023	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	35117000
CY2022	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	35988000
CY2021	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	40823000
CY2023	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	100728000
CY2022	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	91741000
CY2021	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	77157000
CY2023Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	28787000
CY2022Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	19809000
CY2021Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	14566000
CY2023	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-1061000
CY2022	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-6321000
CY2021	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-6838000
CY2023Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	70880000
CY2022Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	65611000
CY2021Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	55753000
CY2023Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1996976000
CY2022Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1869561000
CY2021Q4	insw	Vessels Deferred Dry Dock And Other Property VesselsDeferredDryDockAndOtherProperty	1907894000
CY2023	insw	Number Of Vessels Used As Collateral On Debt NumberOfVesselsUsedAsCollateralOnDebt	42
CY2022Q1	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	3000000.0
CY2022Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	65611000
CY2021Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	55753000
CY2020Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	36334000
CY2023	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	35117000
CY2022	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	35988000
CY2021	insw	Drydock Expenditures Additions DrydockExpendituresAdditions	40823000
CY2023	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	100728000
CY2022	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	91741000
CY2021	insw	Deferred Drydock Expenditures Net Subtotal DeferredDrydockExpendituresNetSubtotal	77157000
CY2023Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	28787000
CY2022Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	19809000
CY2021Q4	insw	Accumulated Amortization Deferred Dry Docking Cost AccumulatedAmortizationDeferredDryDockingCost	14566000
CY2023	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-1061000
CY2022	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-6321000
CY2021	insw	Gain Loss On Disposal Of Assets And Other Non Cash Charges GainLossOnDisposalOfAssetsAndOtherNonCashCharges	-6838000
CY2023Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	70880000
CY2022Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	65611000
CY2021Q4	insw	Deferred Drydock Expenditures Net DeferredDrydockExpendituresNet	55753000
CY2023Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	337900000
CY2023Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	750000000
CY2021	us-gaap	Derivative Loss On Derivative DerivativeLossOnDerivative	4200000
CY2023	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	2000000.0
CY2022	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	2200000
CY2021	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	400000
CY2022Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	358600000
CY2022Q2	us-gaap	Proceeds From Hedge Financing Activities ProceedsFromHedgeFinancingActivities	9600000
CY2022Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	9700000
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet	4100000
CY2022	us-gaap	Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet	3000000.0
CY2023Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	337900000
CY2023Q4	us-gaap	Line Of Credit Facility Maximum Borrowing Capacity LineOfCreditFacilityMaximumBorrowingCapacity	750000000
CY2021	us-gaap	Derivative Loss On Derivative DerivativeLossOnDerivative	4200000
CY2023	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	2000000.0
CY2022	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	2200000
CY2021	us-gaap	Derivative Instruments Loss Reclassified From Accumulated Oci Into Income Effective Portion DerivativeInstrumentsLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortion	400000
CY2022Q2	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	358600000
CY2022Q2	us-gaap	Proceeds From Hedge Financing Activities ProceedsFromHedgeFinancingActivities	9600000
CY2022Q2	us-gaap	Derivative Gain Loss On Derivative Net DerivativeGainLossOnDerivativeNet	9700000
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet	4100000
CY2022	us-gaap	Derivative Instruments Gain Loss Reclassified From Accumulated Oci Into Income Effective Portion Net DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet	3000000.0
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	3187000
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	22905000
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	7896000
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	722676000
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	1023432000
CY2023Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	127447000
CY2022Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	162854000
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	595229000
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	860578000
CY2022Q2	insw	Debt Instrument Basis Spread On Variable Rate1 Increase Decrease DebtInstrumentBasisSpreadOnVariableRate1IncreaseDecrease	0.0005
CY2022Q2	us-gaap	Debt Instrument Basis Spread On Variable Rate1 DebtInstrumentBasisSpreadOnVariableRate1	0.0245
CY2023	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	4000000.0
CY2022	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	1300000
CY2021	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	-6600000
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt Before Write Off Of Deferred Debt Issuance Cost GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost	4200000
CY2023	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	3187000
CY2022	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	22905000
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Parent OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTaxParent	7896000
CY2023Q4	us-gaap	Long Term Debt LongTermDebt	722676000
CY2022Q4	us-gaap	Long Term Debt LongTermDebt	1023432000
CY2023Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	127447000
CY2022Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	162854000
CY2023Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	595229000
CY2022Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	860578000
CY2022Q2	insw	Debt Instrument Basis Spread On Variable Rate1 Increase Decrease DebtInstrumentBasisSpreadOnVariableRate1IncreaseDecrease	0.0005
CY2022Q2	us-gaap	Debt Instrument Basis Spread On Variable Rate1 DebtInstrumentBasisSpreadOnVariableRate1	0.0245
CY2023	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	4000000.0
CY2022	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	1300000
CY2021	insw	Gains Losses On Repurchase And Extinguishment Of Debt GainsLossesOnRepurchaseAndExtinguishmentOfDebt	-6600000
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt Before Write Off Of Deferred Debt Issuance Cost GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost	4200000
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	97000
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	1608000
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	0
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3878000
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	6570000
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	1826000
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	9830000
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	9909000
CY2023Q4	us-gaap	Interest Payable Current InterestPayableCurrent	2114000
CY2022Q4	us-gaap	Interest Payable Current InterestPayableCurrent	7723000
CY2023Q4	us-gaap	Accrued Rent Current And Noncurrent AccruedRentCurrentAndNoncurrent	925000
CY2022Q4	us-gaap	Accrued Rent Current And Noncurrent AccruedRentCurrentAndNoncurrent	2644000
CY2023Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	5208000
CY2022Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	4730000
CY2023Q4	us-gaap	Other Accounts Payable And Accrued Liabilities OtherAccountsPayableAndAccruedLiabilities	1587000
CY2022Q4	us-gaap	Other Accounts Payable And Accrued Liabilities OtherAccountsPayableAndAccruedLiabilities	603000
CY2023Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	6244000
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	2962000
CY2023Q4	us-gaap	Accrued Insurance Current AccruedInsuranceCurrent	85000
CY2022Q4	us-gaap	Accrued Insurance Current AccruedInsuranceCurrent	527000
CY2023Q4	insw	Accrued Vessel Expenses1 AccruedVesselExpenses1	17918000
CY2022Q4	insw	Accrued Vessel Expenses1 AccruedVesselExpenses1	17911000
CY2023Q4	insw	Accrued General And Administrative Expenses AccruedGeneralAndAdministrativeExpenses	1974000
CY2022Q4	insw	Accrued General And Administrative Expenses AccruedGeneralAndAdministrativeExpenses	1293000
CY2023Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	5449000
CY2022Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	941000
CY2023Q4	us-gaap	Accounts Payable And Other Accrued Liabilities Current AccountsPayableAndOtherAccruedLiabilitiesCurrent	57904000
CY2022Q4	us-gaap	Accounts Payable And Other Accrued Liabilities Current AccountsPayableAndOtherAccruedLiabilitiesCurrent	51069000
CY2023Q4	insw	Percent Of Shipping Income Subject To U.S.Federal Taxation PercentOfShippingIncomeSubjectToU.s.FederalTaxation	0.04
CY2023Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	6570000
CY2022Q4	us-gaap	Accounts Payable Current AccountsPayableCurrent	1826000
CY2023Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	9830000
CY2022Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	9909000
CY2023Q4	us-gaap	Interest Payable Current InterestPayableCurrent	2114000
CY2022Q4	us-gaap	Interest Payable Current InterestPayableCurrent	7723000
CY2023Q4	us-gaap	Accrued Rent Current And Noncurrent AccruedRentCurrentAndNoncurrent	925000
CY2022Q4	us-gaap	Accrued Rent Current And Noncurrent AccruedRentCurrentAndNoncurrent	2644000
CY2023Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	5208000
CY2022Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	4730000
CY2023Q4	us-gaap	Other Accounts Payable And Accrued Liabilities OtherAccountsPayableAndAccruedLiabilities	1587000
CY2022Q4	us-gaap	Other Accounts Payable And Accrued Liabilities OtherAccountsPayableAndAccruedLiabilities	603000
CY2023Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	6244000
CY2022Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	2962000
CY2023Q4	us-gaap	Accrued Insurance Current AccruedInsuranceCurrent	85000
CY2022Q4	us-gaap	Accrued Insurance Current AccruedInsuranceCurrent	527000
CY2023Q4	insw	Accrued Vessel Expenses1 AccruedVesselExpenses1	17918000
CY2022Q4	insw	Accrued Vessel Expenses1 AccruedVesselExpenses1	17911000
CY2023Q4	insw	Accrued General And Administrative Expenses AccruedGeneralAndAdministrativeExpenses	1974000
CY2022Q4	insw	Accrued General And Administrative Expenses AccruedGeneralAndAdministrativeExpenses	1293000
CY2023Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	5449000
CY2022Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	941000
CY2023Q4	us-gaap	Accounts Payable And Other Accrued Liabilities Current AccountsPayableAndOtherAccruedLiabilitiesCurrent	57904000
CY2022Q4	us-gaap	Accounts Payable And Other Accrued Liabilities Current AccountsPayableAndOtherAccruedLiabilitiesCurrent	51069000
CY2023Q4	insw	Percent Of Shipping Income Subject To U.S.Federal Taxation PercentOfShippingIncomeSubjectToU.s.FederalTaxation	0.04
CY2023	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	3878000
CY2022	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	97000
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	1608000
CY2023	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	0
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-9000
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	10000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3878000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	88000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1618000
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	3180000
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	3200000
CY2023Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	806000
CY2022Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	806000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	3039000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	2906000
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	7025000
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	6912000
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7025000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	6912000
CY2023Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	12700000
CY2022Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	12800000
CY2023Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	7000000.0
CY2022Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	6900000
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1081000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3551000
CY2022	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-9000
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	10000
CY2023	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	3878000
CY2022	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	88000
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1618000
CY2023Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	3180000
CY2022Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	3200000
CY2023Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	806000
CY2022Q4	us-gaap	Deferred Tax Assets Property Plant And Equipment DeferredTaxAssetsPropertyPlantAndEquipment	806000
CY2023Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	3039000
CY2022Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	2906000
CY2023Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	7025000
CY2022Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	6912000
CY2023Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	7025000
CY2022Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	6912000
CY2023Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	12700000
CY2022Q4	us-gaap	Operating Loss Carryforwards OperatingLossCarryforwards	12800000
CY2023Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	7000000.0
CY2022Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	6900000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	4500000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1000000.0
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	970000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	4500000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1000000.0
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	970000
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	1081000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3551000
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	168000
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	272000
CY2022	us-gaap	Unrecognized Tax Benefits Period Increase Decrease UnrecognizedTaxBenefitsPeriodIncreaseDecrease	7000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	4521000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	970000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3600000
CY2023Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	1000000.0
CY2022Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	700000
CY2021Q3	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	50674393
CY2021Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	50674393
CY2023	us-gaap	Payments Of Dividends PaymentsOfDividends	308200000
CY2023Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	6.29
CY2023Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-05-04
CY2023Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-06-14
CY2023Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-06-28
CY2023Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q2	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.50
CY2023Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	79259000
CY2023Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-08-08
CY2023Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-09-13
CY2023Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-09-27
CY2023Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q3	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.30
CY2023Q3	us-gaap	Payments Of Dividends PaymentsOfDividends	69428000
CY2023Q4	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-11-06
CY2023Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-12-13
CY2023Q4	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-12-27
CY2023Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q4	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.13
CY2023Q4	us-gaap	Payments Of Dividends PaymentsOfDividends	61157000
CY2022Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	1.42
CY2022	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	168000
CY2022	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	272000
CY2022	us-gaap	Unrecognized Tax Benefits Period Increase Decrease UnrecognizedTaxBenefitsPeriodIncreaseDecrease	7000
CY2023Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	4521000
CY2022Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	970000
CY2023	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3600000
CY2023Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	1000000.0
CY2022Q4	us-gaap	Unrecognized Tax Benefits Interest On Income Taxes Accrued UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued	700000
CY2021Q3	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	50674393
CY2023	us-gaap	Payments Of Dividends PaymentsOfDividends	308200000
CY2023Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	6.29
CY2023Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-05-04
CY2023Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-06-14
CY2023Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-06-28
CY2023Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q2	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.50
CY2023Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	79259000
CY2023Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-08-08
CY2023Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-09-13
CY2023Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-09-27
CY2023Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q3	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.30
CY2023Q4	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2023-11-06
CY2023Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2023-12-13
CY2023Q4	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2023-12-27
CY2023Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2023Q4	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.13
CY2023Q4	us-gaap	Payments Of Dividends PaymentsOfDividends	61157000
CY2022	us-gaap	Payments Of Dividends PaymentsOfDividends	69800000
CY2022Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	1.42
CY2022Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-02-28
CY2022Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-03-14
CY2022Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-03-28
CY2022Q1	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2022Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	2978000
CY2022Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-06-07
CY2022Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-06-17
CY2022Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-06-29
CY2022Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	5964000
CY2022Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-08-04
CY2022Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-09-14
CY2022Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-09-28
CY2022Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q3	us-gaap	Payments Of Dividends PaymentsOfDividends	5886000
CY2022Q4	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-11-07
CY2022Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-02-28
CY2022Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-03-14
CY2022Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-03-28
CY2022Q1	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2022Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	2978000
CY2022Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-06-07
CY2022Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-06-29
CY2022Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	5964000
CY2022Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-08-04
CY2022Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-09-14
CY2022Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-09-28
CY2022Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q3	us-gaap	Payments Of Dividends PaymentsOfDividends	5886000
CY2022Q4	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2022-11-07
CY2022Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-12-08
CY2022Q4	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-12-22
CY2022Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q4	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.00
CY2022Q4	us-gaap	Payments Of Dividends PaymentsOfDividends	55015000
CY2021Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.24
CY2021Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-02-23
CY2021Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-03-11
CY2021Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-03-26
CY2021Q1	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	1681000
CY2021Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-06-04
CY2021Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-06-14
CY2021Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-06-28
CY2021Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	1688000
CY2021Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-07-28
CY2021Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-09-09
CY2021Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-09-23
CY2021Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q3	us-gaap	Payments Of Dividends PaymentsOfDividends	3041000
CY2021Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-12-09
CY2021Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	147294
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	513479
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	56065
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Per Share Weighted Average Price Of Shares Purchased ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased	44.09
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Per Share Weighted Average Price Of Shares Purchased ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased	41.79
CY2019Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2023	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2021-03-05
CY2020Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2020Q3	us-gaap	Stock Repurchase Program Period In Force1 StockRepurchaseProgramPeriodInForce1	P24M
CY2020Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2022-08-04
CY2022Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2022-12-08
CY2022Q4	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2022-12-22
CY2022Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.12
CY2022Q4	insw	Supplemental Dividends Payable Amount Per Share SupplementalDividendsPayableAmountPerShare	1.00
CY2022Q4	us-gaap	Payments Of Dividends PaymentsOfDividends	55015000
CY2021Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.24
CY2021Q1	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-02-23
CY2021Q1	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-03-11
CY2021Q1	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-03-26
CY2021Q1	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q1	us-gaap	Payments Of Dividends PaymentsOfDividends	1681000
CY2021Q2	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-06-04
CY2021Q2	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-06-14
CY2021Q2	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-06-28
CY2021Q2	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q2	us-gaap	Payments Of Dividends PaymentsOfDividends	1688000
CY2021Q3	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-07-28
CY2021Q3	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-09-09
CY2021Q3	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-09-23
CY2021Q3	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q3	us-gaap	Payments Of Dividends PaymentsOfDividends	3041000
CY2021Q4	us-gaap	Dividends Payable Date Declared Day Month And Year DividendsPayableDateDeclaredDayMonthAndYear	2021-11-08
CY2021Q4	us-gaap	Dividends Payable Date Of Record Day Month And Year DividendsPayableDateOfRecordDayMonthAndYear	2021-12-09
CY2021Q4	us-gaap	Dividend Payable Date To Be Paid Day Month And Year DividendPayableDateToBePaidDayMonthAndYear	2021-12-23
CY2021Q4	us-gaap	Dividends Payable Amount Per Share DividendsPayableAmountPerShare	0.06
CY2021Q4	us-gaap	Payments Of Dividends PaymentsOfDividends	3023000
CY2023	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	147294
CY2022	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	513479
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Shares Purchased For Award ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward	56065
CY2023Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Per Share Weighted Average Price Of Shares Purchased ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased	44.09
CY2022Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Per Share Weighted Average Price Of Shares Purchased ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased	41.79
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Per Share Weighted Average Price Of Shares Purchased ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased	20.06
CY2019Q1	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2023	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2021-03-05
CY2020Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2020Q3	us-gaap	Stock Repurchase Program Period In Force1 StockRepurchaseProgramPeriodInForce1	P24M
CY2020Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2022-08-04
CY2020Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2020Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000.0
CY2022Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	60000000.0
CY2022Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	33300000
CY2022Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2023-12-31
CY2023Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000.0
CY2023Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	26100000
CY2022Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2023-12-31
CY2023Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2025-12-31
CY2020Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	30000000.0
CY2020Q4	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000.0
CY2022Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	60000000.0
CY2022Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	33300000
CY2022Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2023-12-31
CY2023Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	50000000.0
CY2023Q3	us-gaap	Stock Repurchase Program Authorized Amount1 StockRepurchaseProgramAuthorizedAmount1	26100000
CY2022Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2023-12-31
CY2023Q3	us-gaap	Stock Repurchase Program Expiration Date StockRepurchaseProgramExpirationDate	2025-12-31
CY2023	insw	Schedule Of Shares Repurchased ScheduleOfSharesRepurchased	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="margin-bottom:10pt;visibility:hidden;"></span></p><table style="border-collapse:collapse;font-size:16pt;height:max-content;padding-left:0pt;padding-right:0pt;width:100%;"><tr style="height:1pt;"><td style="vertical-align:bottom;width:27.88%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:22.63%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:24.22%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.58%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.58%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:22.08%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td></tr><tr><td style="vertical-align:bottom;width:27.88%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Year-ended December 31,</p></td><td style="vertical-align:bottom;width:22.63%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Total shares repurchased</p></td><td style="vertical-align:bottom;width:24.22%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Average Price per share</p></td><td style="vertical-align:middle;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;width:22.08%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="white-space:pre-wrap;">Total Cost </span><br/>(<i style="font-style:italic;">In thousands</i>)</p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2023</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">366,483 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$38.03 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">13,937 </p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2022</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">687,740 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$29.08 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">20,000 </p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2021</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">1,077,070 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$15.44 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">16,630 </p></td></tr></table>
CY2023	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	366483
CY2023	insw	Stock Repurchased Per Share Amount StockRepurchasedPerShareAmount	38.03
CY2023	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	13937000
CY2022	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	687740
CY2022	insw	Stock Repurchased Per Share Amount StockRepurchasedPerShareAmount	29.08
CY2022	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	20000000
CY2021	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	1077070
CY2021	insw	Stock Repurchased Per Share Amount StockRepurchasedPerShareAmount	15.44
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	16630000
CY2021Q3	insw	Number Of Directors Added To Board NumberOfDirectorsAddedToBoard	3
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Accelerated Vesting Number SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber	5035
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Equity Instruments Other Than Options Aggregate Intrinsic Value Vested SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested	100000
CY2023Q4	insw	Post Combination Service PostCombinationService	600000
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost	200000
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y25D
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P5Y9M14D
CY2023	us-gaap	Restricted Stock Expense RestrictedStockExpense	7900000
CY2022	us-gaap	Restricted Stock Expense RestrictedStockExpense	5500000
CY2021	us-gaap	Restricted Stock Expense RestrictedStockExpense	9300000
CY2023	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	600000
CY2022	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	1000000.0
CY2021	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	1200000
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	8300000
CY2023	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y6M25D
CY2023	insw	Schedule Of Shares Repurchased ScheduleOfSharesRepurchased	<p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt;"><span style="margin-bottom:10pt;visibility:hidden;"></span></p><table style="border-collapse:collapse;font-size:16pt;height:max-content;padding-left:0pt;padding-right:0pt;width:100%;"><tr style="height:1pt;"><td style="vertical-align:bottom;width:27.88%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:22.63%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:24.22%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.58%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:middle;width:1.58%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="position:absolute;top:50%;transform:translate(0,-50%);width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td><td style="vertical-align:bottom;width:22.08%;margin:0pt;padding:0pt;"><div style="height:1pt;overflow:hidden;overflow-wrap:break-word;position:relative;"><div style="bottom:0pt;position:absolute;width:100%;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="font-size:1pt;visibility:hidden;"></span></p></div></div></td></tr><tr><td style="vertical-align:bottom;width:27.88%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Year-ended December 31,</p></td><td style="vertical-align:bottom;width:22.63%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Total shares repurchased</p></td><td style="vertical-align:bottom;width:24.22%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">Average Price per share</p></td><td style="vertical-align:middle;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:middle;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;width:22.08%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;border-top:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;"><span style="white-space:pre-wrap;">Total Cost </span><br/>(<i style="font-style:italic;">In thousands</i>)</p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2023</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">366,483 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$38.03 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">13,937 </p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2022</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">687,740 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$29.08 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">20,000 </p></td></tr><tr><td style="vertical-align:bottom;white-space:nowrap;width:27.88%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:center;margin:0pt 0pt 0.05pt 0pt;">2021</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.63%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">1,077,070 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:24.22%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">$15.44 </p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;"><span style="visibility:hidden;"></span></p></td><td style="vertical-align:bottom;white-space:nowrap;width:1.58%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;margin:0pt 0pt 0.05pt 0pt;">$</p></td><td style="vertical-align:bottom;white-space:nowrap;width:22.08%;background:#cceeff;border-bottom:1px solid #000000;border-left:1px solid #000000;border-right:1px solid #000000;margin:0pt;padding:0pt;"><p style="font-family:'Times New Roman','Times','serif';font-size:10pt;text-align:right;margin:0pt 3pt 0.05pt 0pt;">16,630 </p></td></tr></table>
CY2023	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	366483
CY2023	insw	Stock Repurchased Per Share Amount StockRepurchasedPerShareAmount	38.03
CY2023	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	13937000
CY2022	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	20000000
CY2021	us-gaap	Stock Repurchased And Retired During Period Shares StockRepurchasedAndRetiredDuringPeriodShares	1077070
CY2021	insw	Stock Repurchased Per Share Amount StockRepurchasedPerShareAmount	15.44
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	16630000
CY2021Q3	insw	Number Of Directors Added To Board NumberOfDirectorsAddedToBoard	3
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Accelerated Vesting Number SharebasedCompensationArrangementBySharebasedPaymentAwardAcceleratedVestingNumber	5035
CY2021Q3	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Equity Instruments Other Than Options Aggregate Intrinsic Value Vested SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested	100000
CY2023Q4	insw	Post Combination Service PostCombinationService	600000
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Accelerated Compensation Cost ShareBasedCompensationArrangementByShareBasedPaymentAwardAcceleratedCompensationCost	200000
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Outstanding Weighted Average Remaining Contractual Term2 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2	P6Y25D
CY2023	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1	P5Y9M14D
CY2023	us-gaap	Restricted Stock Expense RestrictedStockExpense	7900000
CY2022	us-gaap	Restricted Stock Expense RestrictedStockExpense	5500000
CY2021	us-gaap	Restricted Stock Expense RestrictedStockExpense	9300000
CY2023	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	600000
CY2022	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	1000000.0
CY2021	insw	Stock Options Compensation Expense Income StockOptionsCompensationExpenseIncome	1200000
CY2023Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	8300000
CY2023Q4	us-gaap	Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax AociLossCashFlowHedgeCumulativeGainLossAfterTax	9349000
CY2022Q4	us-gaap	Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax AociLossCashFlowHedgeCumulativeGainLossAfterTax	16912000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	10412000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	9948000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1063000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	6964000
CY2023	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	10171000
CY2022	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	822000
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	-11723000
CY2023Q4	us-gaap	Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax AociLossCashFlowHedgeCumulativeGainLossAfterTax	9349000
CY2022Q4	us-gaap	Aoci Loss Cash Flow Hedge Cumulative Gain Loss After Tax AociLossCashFlowHedgeCumulativeGainLossAfterTax	16912000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	10412000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax	9948000
CY2023Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-1063000
CY2022Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	6964000
CY2023	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	10171000
CY2022	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	822000
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodBeforeTax	-11723000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	1700000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax	1400000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-10400000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax	-9000000.0
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassification From Accumulated Oci To Income Estimated Net Amount To Be Transferred DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred	-5300000
CY2023	insw	Lease Cancellation Period Notice LeaseCancellationPeriodNotice	P90D
CY2023	us-gaap	Revenues Revenues	1071775000
CY2022	us-gaap	Revenues Revenues	864665000
CY2021	us-gaap	Revenues Revenues	272546000
CY2022Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	1866000
CY2023Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	6512000
CY2021	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2022	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2023	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2023Q4	us-gaap	Capitalized Contract Cost Gross CapitalizedContractCostGross	0
CY2023	us-gaap	Lease Cost LeaseCost	26775000
CY2022	us-gaap	Lease Cost LeaseCost	19884000
CY2021	us-gaap	Lease Cost LeaseCost	15528000
CY2023	insw	Excluded Vessels Chartered Period ExcludedVesselsCharteredPeriod	P1M
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	6028000
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	10207000
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	10464000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	1700000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax	1400000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	-10400000
CY2023Q4	us-gaap	Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses After Tax DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax	-9000000.0
CY2023	us-gaap	Derivative Instruments Gain Loss Reclassification From Accumulated Oci To Income Estimated Net Amount To Be Transferred DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred	-5300000
CY2023	insw	Lease Cancellation Period Notice LeaseCancellationPeriodNotice	P90D
CY2023	us-gaap	Revenues Revenues	1071775000
CY2022	us-gaap	Revenues Revenues	864665000
CY2021	us-gaap	Revenues Revenues	272546000
CY2022Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	9452000
CY2022Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	1866000
CY2023Q4	us-gaap	Accounts Receivable Net AccountsReceivableNet	6512000
CY2023Q4	us-gaap	Contract With Customer Asset Net ContractWithCustomerAssetNet	1029000
CY2021	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2022	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2023	us-gaap	Contract With Customer Performance Obligation Satisfied In Previous Period ContractWithCustomerPerformanceObligationSatisfiedInPreviousPeriod	0
CY2023Q4	us-gaap	Capitalized Contract Cost Gross CapitalizedContractCostGross	0
CY2023	us-gaap	Lease Cost LeaseCost	26775000
CY2022	us-gaap	Lease Cost LeaseCost	19884000
CY2021	us-gaap	Lease Cost LeaseCost	15528000
CY2023	insw	Excluded Vessels Chartered Period ExcludedVesselsCharteredPeriod	P1M
CY2023	us-gaap	Operating Lease Payments OperatingLeasePayments	6028000
CY2022	us-gaap	Operating Lease Payments OperatingLeasePayments	10207000
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	10464000
CY2023	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	42284000
CY2022	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	533000
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	20391000
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	8471000
CY2022Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	44391000
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	10223000
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	1596000
CY2022Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	41870000
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	11631000
CY2023Q4	insw	Operating And Financing Lease Liability OperatingAndFinancingLeaseLiability	21854000
CY2023	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	42284000
CY2022	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	533000
CY2023Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	20391000
CY2022Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	8471000
CY2022Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	44391000
CY2023Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	10223000
CY2022Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	1596000
CY2022Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	41870000
CY2023Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	11631000
CY2022Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	7740000
CY2023Q4	insw	Operating And Financing Lease Liability OperatingAndFinancingLeaseLiability	21854000
CY2022Q4	insw	Operating And Financing Lease Liability OperatingAndFinancingLeaseLiability	51206000
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y5M1D
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y6M21D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0590
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0413
CY2022Q4	us-gaap	Lessee Finance Lease Discount Rate LesseeFinanceLeaseDiscountRate	0.0478
CY2023	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	827000
CY2022	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	442000
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	360000
CY2023	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1080000
CY2022	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	955000
CY2021	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1053000
CY2023	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	74000
CY2022	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	73000
CY2021	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	80000
CY2023	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-506000
CY2022	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-235000
CY2021	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-304000
CY2023	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	327000
CY2022	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-205000
CY2021	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-309000
CY2023	insw	Defined Benefit Plan Unrecognized Actuarial Losses Amortization Period DefinedBenefitPlanUnrecognizedActuarialLossesAmortizationPeriod	P14Y
CY2022Q4	insw	Operating And Financing Lease Liability OperatingAndFinancingLeaseLiability	51206000
CY2023Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P4Y5M1D
CY2022Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y6M21D
CY2023Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0590
CY2022Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0413
CY2022Q4	us-gaap	Lessee Finance Lease Discount Rate LesseeFinanceLeaseDiscountRate	0.0478
CY2023	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	827000
CY2022	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	442000
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	360000
CY2023	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1080000
CY2022	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	955000
CY2021	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	1053000
CY2023	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	74000
CY2022	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	73000
CY2021	us-gaap	Defined Benefit Plan Amortization Of Prior Service Cost Credit DefinedBenefitPlanAmortizationOfPriorServiceCostCredit	80000
CY2023	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-506000
CY2022	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-235000
CY2021	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-304000
CY2023	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	327000
CY2022	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-205000
CY2021	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-309000
CY2023	insw	Defined Benefit Plan Unrecognized Actuarial Losses Amortization Period DefinedBenefitPlanUnrecognizedActuarialLossesAmortizationPeriod	P14Y
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	600000
CY2023Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0455
CY2022Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0490
CY2023	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0490
CY2022	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0180
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0120
CY2023	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0637
CY2022	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0348
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0336
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	1123000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	1096000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	1277000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	1066000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	1127000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	6078000
CY2023Q4	insw	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	11767000
CY2023Q4	us-gaap	Defined Benefit Plan Plan Assets Target Allocation Percentage DefinedBenefitPlanPlanAssetsTargetAllocationPercentage	1
CY2023	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	700000
CY2022	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	600000
CY2023Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0455
CY2022Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0490
CY2023	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0490
CY2022	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0180
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0120
CY2023	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0637
CY2022	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0348
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0336
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	1123000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	1096000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	1277000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	1066000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	1127000
CY2023Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	6078000
CY2023Q4	insw	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	11767000
CY2023Q4	us-gaap	Defined Benefit Plan Plan Assets Target Allocation Percentage DefinedBenefitPlanPlanAssetsTargetAllocationPercentage	1
CY2023	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	700000
CY2022	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	600000
CY2021	us-gaap	Defined Contribution Plan Employer Discretionary Contribution Amount DefinedContributionPlanEmployerDiscretionaryContributionAmount	600000
CY2023	us-gaap	Investment Income Interest InvestmentIncomeInterest	13963000
CY2022	us-gaap	Investment Income Interest InvestmentIncomeInterest	3653000
CY2021	us-gaap	Investment Income Interest InvestmentIncomeInterest	104000
CY2023	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	510000
CY2022	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	647000
CY2021	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	667000
CY2023	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	2686000
CY2022	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	1266000
CY2021	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	2113000
CY2023	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	-1323000
CY2021	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	-4465000
CY2022	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	135000
CY2023	insw	Other Other Income Expense OtherOtherIncomeExpense	188000
CY2022	insw	Other Other Income Expense OtherOtherIncomeExpense	-567000
CY2021	insw	Other Other Income Expense OtherOtherIncomeExpense	-140000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	10652000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2332000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-5947000
CY2023Q3	us-gaap	Loss Contingency Damages Sought Value LossContingencyDamagesSoughtValue	25000000
CY2023Q3	us-gaap	Loss Contingency Accrual At Carrying Value LossContingencyAccrualAtCarryingValue	0
CY2023Q4	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023	us-gaap	Investment Income Interest InvestmentIncomeInterest	13963000
CY2022	us-gaap	Investment Income Interest InvestmentIncomeInterest	3653000
CY2021	us-gaap	Investment Income Interest InvestmentIncomeInterest	104000
CY2023	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	510000
CY2022	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	647000
CY2021	insw	Other Net Actuarial Gain Loss Related To Pension OtherNetActuarialGainLossRelatedToPension	667000
CY2023	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	2686000
CY2022	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	1266000
CY2021	us-gaap	Write Off Of Deferred Debt Issuance Cost WriteOffOfDeferredDebtIssuanceCost	2113000
CY2023	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	-1323000
CY2021	us-gaap	Gain Loss On Repurchase Of Debt Instrument GainLossOnRepurchaseOfDebtInstrument	-4465000
CY2022	us-gaap	Other Nonoperating Expense OtherNonoperatingExpense	135000
CY2023	insw	Other Other Income Expense OtherOtherIncomeExpense	188000
CY2022	insw	Other Other Income Expense OtherOtherIncomeExpense	-567000
CY2021	insw	Other Other Income Expense OtherOtherIncomeExpense	-140000
CY2023	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	10652000
CY2022	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	2332000
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-5947000
CY2023Q3	us-gaap	Loss Contingency Damages Sought Value LossContingencyDamagesSoughtValue	25000000
CY2023Q3	us-gaap	Loss Contingency Accrual At Carrying Value LossContingencyAccrualAtCarryingValue	0
CY2023Q4	ecd	Rule10b51 Arr Adopted Flag Rule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Rule10b51 Arr Trmntd Flag Rule10b51ArrTrmntdFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Adopted Flag NonRule10b51ArrAdoptedFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false
CY2023Q4	ecd	Non Rule10b51 Arr Trmntd Flag NonRule10b51ArrTrmntdFlag	false

Files In Submission

Name	View Source	Status
insw-20231231_pre.xml	Edgar Link	unprocessable
insw-20231231x10k_htm.xml	Edgar Link	completed
0001558370-24-002108-index-headers.html	Edgar Link	pending
0001558370-24-002108-index.html	Edgar Link	pending
0001558370-24-002108.txt	Edgar Link	pending
0001558370-24-002108-xbrl.zip	Edgar Link	pending
Financial_Report.xlsx	Edgar Link	pending
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$INSW
International Seaways, Inc. Stock $insw

2024 Q1 Form 10-K Financial Statement

#000155837024002108 Filed on February 29, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$INSW International Seaways, Inc. Stock $insw

2024 Q1 Form 10-K Financial Statement

#000155837024002108 Filed on February 29, 2024

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$INSW
International Seaways, Inc. Stock $insw