Document And Entity Information Statistical Measurement [Axis] Note To Financial Statement Details Textual Note 3 - Allowance for Credit Losses Income tax expense Income Tax Expense (Benefit) Note 5 - Stockholders' Equity and Dilutive Equity Instruments Pension Plan [Member] ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Note 7 - Employee Benefit Plans ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Note 8 - Debt Trading Arrangements, by Individual [Table] Note 11 - Properties and Equipment, Accrued Expenses, Other Current Liabilities and Other Liabilities Retirement Benefits [Text Block] Material Terms of Trading Arrangement [Text Block] Note 12 - Derivative Instruments and Hedging Activities DNB Bank ASA, New York [Member] DNB Bank ASA, New York Note 13 - Segment and Geographic Distribution of Operations Note 3 - Allowance for Credit Losses - Schedule for Allowance for Credit Losses on Financing Receivables (Details) Note 5 - Stockholders' Equity and Dilutive Equity Instruments - Changes in Accumulated Other Comprehensive Income (Loss) (Details) Note 5 - Stockholders' Equity and Dilutive Equity Instruments - Dilutive Equity Instruments (Details) Minimum [Member] Note 5 - Stockholders' Equity and Dilutive Equity Instruments - Dilutive Equity Instruments (Details) (Parentheticals) Product and Service, Other [Member] Foreign exchange gain (loss) Note 7 - Employee Benefit Plans - Net Periodic Benefit Costs (Details) Statistical Measurement [Domain] Note 8 - Debt - Summary of Debt Outstanding (Details) Maximum [Member] Note 8 - Debt - Summary of Debt Outstanding (Details) (Parentheticals) Share Repurchase Program [Axis] Note 11 - Properties and Equipment, Accrued Expenses, Other Current Liabilities and Other Liabilities - Summary of Property and Equipment (Details) Share Repurchase Program [Domain] Note 11 - Properties and Equipment, Accrued Expenses, Other Current Liabilities and Other Liabilities - Summary of Accrued Expenses (Details) Nordic Bond 1 [Member] Nordic Bond 1 Note 11 - Properties and Equipment, Accrued Expenses, Other Current Liabilities and Other Liabilities - Summary of Other Current Liabilities (Details) Note 11 - Properties and Equipment, Accrued Expenses, Other Current Liabilities and Other Liabilities - Other liabilities and Deferred Credits (Details) Retirement Plan Type [Domain] tdw_LineOfCreditFacilityMinimumBorrowingCapacityPercentOfInterestbearingDebt Line of Credit Facility, Minimum Borrowing Capacity, Percent of Interest-bearing Debt Minimum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility, as a percent of interest-bearing debt. Note 12 - Derivative Instruments and Hedging Activities - Schedule of Derivative Instruments (Details) tdw_LineOfCreditFacilityMinimumBorrowingCommitment Line of Credit Facility, Minimum Borrowing Commitment Minimum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. Note 13 - Segment and Geographic Distribution of Operations - Segment Reporting Information (Details) tdw_RatioOfInterestbearingDebtToEbitda Ratio of Interest-bearing Debt to EBITDA Ratio of Interest-bearing Debt to EBITDA Amortization of below market contracts Notes To Financial Statements Retirement Plan Type [Axis] tdw_RatioOfFairMarketValueOfCollateralToOutstandingDebt Ratio of Fair Market Value of Collateral to Outstanding Debt Ratio of Fair Market Value of Collateral to Outstanding Debt Notes To Financial Statements [Abstract] us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses Amortization of net actuarial gains Crew costs us-gaap_ForeignCurrencyTransactionGainLossUnrealized Unrealized foreign exchange (gain) loss Bareboat Charter Agreement [Member] Bareboat Charter Agreement us-gaap_DefinedBenefitPlanContributionsByEmployer Defined Benefit Plan, Plan Assets, Contributions by Employer Margin Rate [Member] Margin Rate Applicable Margin Rate [Member] Applicable Margin Rate Income Tax Jurisdiction [Domain] tdw_StockRepurchasedAndRetiredDuringPeriodAmount Repurchase and retirement of common stock The amount of stock repurchased and retired during the period. us-gaap_DefinedBenefitPlanInterestCost Interest cost Interest income and other, net us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets Expected return on plan assets us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost Net periodic pension cost Segment Reporting [Text Block] us-gaap_DefinedBenefitPlanBenefitObligation Defined Benefit Plan, Benefit Obligation Segment Reporting [Table Text Block] Award Type [Axis] Adjustments to reconcile net income to net cash provided by operating activities: us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and equity Consolidation Items [Axis] Segment Reporting [Table] Location, Statement of Financial Position, Balance [Axis] Stock-based compensation expense Consolidation Items [Domain] us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet Debt discount and issuance costs us-gaap_IncreaseDecreaseInAccountsPayableTrade Accounts payable The 2023 Notes [Member] Represents the notes due in 2030. Changes in assets and liabilities: us-gaap_IncreaseDecreaseInAccruedLiabilities Accrued expenses us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net change in cash, cash equivalents and restricted cash Effects of exchange rate changes on cash, cash equivalents and restricted cash Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Statement [Table] Credit Facility [Axis] Credit Facility [Domain] tdw_NumberOfVesselsUnderFinanceLeases Number of Vessels Under Finance Leases Number of vessels under finance lease. Revolving Credit Facility [Member] Vessels and related equipment us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate us-gaap_FinanceLeasePrincipalPayments Payments on finance leases us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Lender [Domain] us-gaap_DerivativeLiabilities Derivative Liability Financing Receivable, Allowance for Credit Loss [Table Text Block] Lender Name [Axis] srt_StockRepurchaseProgramAuthorizedAmount1 Share Repurchase Program, Authorized, Amount Long-Term Debt, Type [Axis] Product and Service [Domain] Other properties and equipment Product and Service [Axis] us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables Trade and other receivables Revision of Prior Period [Domain] Revision of Prior Period [Axis] Commitments and Contingencies Disclosure [Text Block] Statement [Line Items] Fair Value Hierarchy and NAV [Axis] Common stock, shares issued (in shares) Common stock, shares outstanding (in shares) Award Type [Domain] Common stock, shares authorized (in shares) tdw_LitigationSettlementReimbursableFees Litigation Settlement, Reimbursable Fees The amount of reimbursable fees for the litigation case. Schedule of Accrued Liabilities [Table Text Block] Common stock of $0.001 par value, 125,000,000 shares authorized, 49,754,957 and 49,566,334 shares issued and outstanding at June 30, 2026 and December 31, 2025, respectively The Wilson Companies [Member] Related to the Wilson Companies. Strike price per common share (in dollars per share) Accounts payable us-gaap_PolicyTextBlockAbstract Accounting Policies tdw_NumberOfVesselsPurchased Number of Vessels Purchased The number of vessels purchased. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables us-gaap_ComprehensiveIncomeNetOfTax Total comprehensive income us-gaap_FinanceLeaseLiabilityCurrent Finance lease liability Additions to properties and equipment us-gaap_AccruedLiabilitiesCurrent Accrued expenses Accrued Liabilities, Current tdw_NumberOfPlatformSupplyVessels Number of Platform Supply Vessels The number of platform supply vessels. tdw_InterestAndOtherDebtCostsNet Interest and other debt costs, net The amount of interest and other debt costs. Americas [Member] Continents of North and South America. Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Payroll and related payables Other accrued expenses Accrued interest expense Proceeds from asset dispositions Proceeds from Sale of Productive Assets Current portion of long-term debt Less: Current portion of long-term debt Long-term debt Total long-term debt Income Tax Jurisdiction, Domestic Federal [Member] Loss Contingencies [Table] Statement of Stockholders' Equity [Abstract] Statement of Comprehensive Income [Abstract] Class of Warrant or Right [Axis] Class of Warrant or Right [Domain] Statement of Cash Flows [Abstract] Long-Term Debt, Type [Domain] Equity Components [Axis] Equity Component [Domain] Fair Value, Inputs, Level 2 [Member] Vessel operating costs Total vessel operating costs Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Equity [Text Block] AOCI Attributable to Parent [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Asset Acquisition [Domain] Asset Acquisition [Table] Asset Acquisition [Axis] Insurance Net properties and equipment Properties and equipment, net Share Repurchase Program [Member] Relating to a share repurchase program. us-gaap_PropertyPlantAndEquipmentGross Property, Plant, and Equipment, before Accumulated Depreciation, Depletion, and Amortization Pension liabilities Asia Pacific [Member] Represents Asia Pacific. Purchase of vessels Current period credit for expected credit losses Middle East [Member] Represents the middle east. Deferred tax assets Costs of other operating revenues Repair and maintenance Schedule of Net Benefit Costs [Table Text Block] Other us-gaap_GainLossOnDispositionOfAssets Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Gain on asset dispositions, net Supplemental disclosure of cash flow information: Current liabilities: us-gaap_LiabilitiesCurrent Total current liabilities Secured Overnight Financing Rate (SOFR) [Member] us-gaap_LongTermDebtFairValue Long-Term Debt, Fair Value Marine operating supplies Income taxes Allowance for Credit Losses [Text Block] Gain on asset dispositions, net Gain on asset dispositions, net Vessel [Member] Represents vessel. Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Supplemental Employee Retirement Plan [Member] Less accumulated depreciation and amortization Amortization of deferred drydocking and survey costs Amount of amortization of dry docking and survey costs. Accumulated other comprehensive income General and administrative us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Income before income taxes Additional paid-in capital Debt Disclosure [Text Block] Noncontrolling interests Prepaid expenses and other current assets Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] us-gaap_PaymentsToAcquireProductiveAssets Payments to Acquire Productive Assets Schedule of Total Shares Outstanding Including Warrants and Restricted Stock Units [Table Text Block] The tabular disclosure of total shares outstanding including warrants and restricted stock units. us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Additions to properties and equipment New Creditor Warrants [Member] Represents the new creditor warrants. GulfMark Creditor Warrants [Member] Represents the GulfMark creditor warrants. Long-term debt, gross us-gaap_DebtInstrumentCarryingAmount Long-Term Debt, Gross Total (in shares) The number of shares outstanding and the aggregate number of common shares reserved for future issuance. us-gaap_StockRepurchasedAndRetiredDuringPeriodValue Stock Repurchased and Retired During Period, Value us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Current assets: tdw_NumberOfVessels Number of Vessels The number of vessels. us-gaap_AssetsCurrent Total current assets Operating profit us-gaap_LitigationSettlementAmountAwardedFromOtherParty Litigation Settlement, Amount Awarded from Other Party Debt Instrument, Name [Domain] Accrued vessel expenses Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to vessel expenses. West Africa [Member] Represent west Africa. Interest rate Debt Instrument, Interest Rate, Stated Percentage Fair Value Measurement Inputs and Valuation Techniques [Table] us-gaap_GainLossOnSaleOfDerivatives Gain (Loss) on Sale of Derivatives tdw_NumberOfVesselsSold Number of Vessels Sold The number of vessels sold. us-gaap_StockRepurchasedAndRetiredDuringPeriodShares Stock Repurchased and Retired During Period, Shares (in shares) Europe and Mediterranean [Member] Represents Europe and the Mediterranean. Schedule of Long-Term Debt Instruments [Table] Debt Instrument [Axis] us-gaap_UnrealizedGainLossOnDerivatives Unrealized Gain (Loss) on Derivatives Cash flows from investing activities: us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities Cash flows from financing activities: us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities us-gaap_PaymentsOfDebtIssuanceCosts Debt issuance costs us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash used in financing activities Liability for uncertain tax positions Proceeds from sale of notes Pillar Two Adjustments [Member] Pillar Two Adjustments Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Domain] us-gaap_DebtInstrumentRedemptionPricePercentage Debt Instrument, Redemption Price, Percentage Operating Segments [Member] Accounting Policies [Abstract] Segments [Domain] Debt Instrument, Redemption, Period One [Member] Debt Instrument, Redemption, Period Two [Member] Accounting Standards Update and Change in Accounting Principle [Text Block] Allowance for credit losses Segments [Axis] us-gaap_StockRepurchasedDuringPeriodShares Stock Repurchased During Period, Shares (in shares) Restricted Stock Units and Stock Options [Member] Information pertaining restricted stock units and stock options. Income Statement [Abstract] Amortization of share-based awards The value of stock issued during the period for amortization and cancellation of restricted stock. tdw_ShareRepurchaseProgramExciseTaxPercent Share Repurchase Program, Excise Tax, Percent Percentage of excise tax on share purchased under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. Deferred drydocking and survey costs us-gaap_NumberOfOperatingSegments Number of Operating Segments us-gaap_NumberOfReportableSegments Number of Reportable Segments Deferred income taxes provision Other us-gaap_OtherSundryLiabilitiesNoncurrent us-gaap_NetIncomeLoss Net income attributable to Tidewater Inc. Swire Pacific Offshore Holdings Ltd. [Member] Related to acquired business. Costs and expenses: Accounting Standards Update [Domain] Corporate expenses Total costs and expenses Income Tax Disclosure [Text Block] Accounting Standards Update and Change in Accounting Principle [Table] us-gaap_DeferredTaxAssetsLiabilitiesNet Deferred Tax Assets, Net Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Fair Value Hierarchy and NAV [Domain] Delivery of Vessels Per Arrangement [Member] Pertains to the terms of the arrangement. Other income (expense): Statement of Financial Position [Abstract] us-gaap_DeferredTaxAssetsValuationAllowance Deferred Tax Assets, Valuation Allowance us-gaap_NonoperatingIncomeExpense Total other expense Vessel Facility Agreements [Member] Pertains to the Vessel Facility Agreements. us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs Write offs Pillar 2 Top Up Tax [Member] Related to Pillar 2 Top Up Tax. Net CFC Tested Income (NCTI) and Subpart F Income [Member] Related to tax adjustment. us-gaap_RepaymentsOfSecuredDebt Principal payments on long-term debt Other assets us-gaap_PaymentsForRepurchaseOfCommonStock Purchase of common stock Document Type Document Information [Line Items] Document Quarterly Report Document Information [Table] Entity Interactive Data Current Document Transition Report us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding Adjusted weighted average common shares (in shares) Fuel, lube and supplies Costs of maintenance supplies used that are directly related to goods produced and sold, or services rendered, and fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. Dilutive effect of warrants and restricted stock units (in shares) Weighted average common shares outstanding (in shares) tdw_IncreaseDecreaseInCashPaidForDeferredDrydockingAndSurveyCosts Deferred drydocking and survey costs Represents the amount of increase (decrease) in cash paid for deferred drydocking and survey costs. Derivative Instrument [Axis] Basic income per common share (in dollars per share) Other Current Liabilities [Table Text Block] Debt incurred for purchase of vessels Effective Income Tax Rate Reconciliation [Table] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Income Tax Jurisdiction [Axis] Amortization of debt premium and discounts Revision of Prior Period, Adjustment [Member] Document Fiscal Period Focus Document Fiscal Year Focus Other Assets Accrued Expenses Other Current Liabilities And Other Liabilities And Deferred Credits [Text Block] The entire disclosure represents a summary of accrued expenses, other current liabilities, other liabilities and deferred credits. Depreciation and amortization Depreciation and amortization Amendment Flag Common Stock [Member] Document Period End Date Long-Lived Asset, Class [Domain] Legal Entity [Axis] Business Combination [Domain] Entity File Number Entity Tax Identification Number Supplemental disclosure of noncash investing activities: Business Combination [Axis] Disaggregation of Revenue [Table] Entity [Domain] Entity Central Index Key Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax Change in liability of pension plans Current Fiscal Year End Date Entity Filer Category Entity Shell Company Entity Emerging Growth Company Entity Small Business Operating income Operating income Hedging Designation [Domain] us-gaap_DerivativeAssets Derivative Asset us-gaap_ContractWithCustomerLiabilityRevenueRecognized Contract with Customer, Liability, Revenue Recognized Derivative Instruments and Hedging Activities Disclosure [Text Block] Revenues: Entity Address, State or Province Entity Address, City or Town us-gaap_ContractWithCustomerAssetNetNoncurrent Contract with Customer, Asset, after Allowance for Credit Loss, Noncurrent Accumulated deficit Entity Address, Address Line One Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] us-gaap_ContractWithCustomerAssetNetCurrent Contract with Customer, Asset, after Allowance for Credit Loss, Current City Area Code us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet Other, net us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation Share based awards reacquired to pay taxes Local Phone Number Entity Address, Postal Zip Code Revenue from Contract with Customer [Text Block] Derivative [Table] Title of 12(b) Security Security Exchange Name Trading Symbol Class of Stock [Axis] Variable Rate [Axis] Variable Rate [Domain] Foreign Exchange Contract [Member] Entity Common Stock, Shares Outstanding Other comprehensive income (loss): Hedging Designation [Axis] Other us-gaap_OtherSundryLiabilitiesCurrent Trade and other receivables, net of allowance for credit losses of $1,132 and $3,034 at June 30, 2026 and December 31, 2025, respectively Net loss attributable to noncontrolling interests Net income Net income Not Designated as Hedging Instrument [Member] Taxes payable Accrued Income Taxes, Current us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsRemainderOfFiscalYear Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax Before reclassifications Property, Plant, and Equipment [Table] Common stock, par value (in dollars per share) Indemnification assets Accounting Standards Update [Axis] Derivative Contract [Domain] Long-Lived Asset, Class [Axis] Receivable [Domain] Total assets Total assets Cash and cash equivalents Common stock shares reserved (in shares) us-gaap_AllowanceForDoubtfulAccountsReceivable Balance Balance Diluted income per common share (in dollars per share) us-gaap_ContractWithCustomerLiabilityNoncurrent Contract with Customer, Liability, Noncurrent us-gaap_ContractWithCustomerLiabilityCurrent Contract with Customer, Liability, Current Depreciation Schedule of Derivative Instruments [Table Text Block] Other Liabilities [Table Text Block] us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral Other current liabilities Accounts and Financing Receivables [Table] Segment Reporting, Reconciling Item, Corporate Nonsegment [Member] us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral Other current assets Trade Accounts Receivable [Member] Receivable Type [Axis] Interest, net of amounts capitalized Schedule of Long-Term Debt Instruments [Table Text Block] us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest Total comprehensive income (loss) us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Total equity Balance at March 31, 2026 and 2025 Balance at June 30, 2026 and 2025 Equity: Business Combination [Text Block] Noncontrolling Interest [Member] us-gaap_StockholdersEquity Total stockholders’ equity Stock, Class of Stock [Table] Foreign Exchange Forward [Member] us-gaap_FinanceLeaseRightOfUseAsset Finance Lease, Right-of-Use Asset, after Accumulated Amortization Fed Funds Effective Rate Overnight Index Swap Rate [Member] us-gaap_OtherLiabilitiesCurrent Other current liabilities Other Liabilities, Current Other liabilities Other Liabilities, Noncurrent ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] Property, Plant, and Equipment [Table Text Block] Revenue ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Pension Plan And Supplemental Plan [Member] Represents the Pension Plan And Supplemental Plan. Commitments and contingencies