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Indebtedness - Senior Debt Notes - Additional Information (Detail) | 12 Months Ended |  | 3 Months Ended |  |  |  | 1 Months Ended |  | 1 Months Ended |  | 3 Months Ended |  | 1 Months Ended |  | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended |  |  | 12 Months Ended | 0 Months Ended | 12 Months Ended |  |  | 12 Months Ended | 0 Months Ended |  |  | 12 Months Ended
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Mar. 31, 2014 USD ($) | Mar. 31, 2015 USD ($) | Jun. 30, 2013 Troms Offshore Supply AS USD ($) | Jun. 30, 2013 Troms Offshore Supply AS NOK | Mar. 31, 2015 Troms Offshore Supply AS USD ($) | Mar. 31, 2015 Troms Offshore Supply AS NOK | Mar. 31, 2014 Troms Offshore Supply AS Floating rate debt USD ($) | Mar. 31, 2014 Troms Offshore Supply AS Floating rate debt NOK | Mar. 31, 2015 Troms Offshore Supply AS Fixed rate debt USD ($) | Mar. 31, 2015 Troms Offshore Supply AS Fixed rate debt NOK | Mar. 31, 2015 Troms Offshore Supply AS Fixed rate debt U.S. dollar denominated debt USD ($) | May 31, 2014 Notes Due May 2015 Troms Offshore Supply AS USD ($) | May 31, 2012 Notes Due May 2015 Troms Offshore Supply AS NOK | Jun. 30, 2013 Senior Notes Due 2019 Troms Offshore Supply AS NOK | Mar. 31, 2015 Notes Due April 2027 Troms Offshore Supply AS USD ($) | Jan. 31, 2014 Notes Due January 2026 Troms Offshore Supply AS NOK | Mar. 31, 2015 Notes Due January 2026 Troms Offshore Supply AS USD ($) | Mar. 31, 2015 Notes Due January 2026 Troms Offshore Supply AS NOK | Jan. 31, 2014 Notes Due May 2024 Troms Offshore Supply AS | May 31, 2012 Notes Due May 2024 Troms Offshore Supply AS NOK | Mar. 31, 2015 Notes Due May 2024 Troms Offshore Supply AS USD ($) | Mar. 31, 2015 Notes Due May 2024 Troms Offshore Supply AS NOK | Sep. 30, 2013 Public bonds Troms Offshore Supply AS USD ($) | Sep. 30, 2013 Public bonds Troms Offshore Supply AS NOK | Mar. 31, 2015 Minimum | May 31, 2012 Minimum Notes Due May 2015 Troms Offshore Supply AS | Jun. 30, 2013 Minimum Senior Notes Due 2019 Troms Offshore Supply AS | Jan. 31, 2014 Minimum Notes Due January 2026 Troms Offshore Supply AS | Mar. 31, 2015 Maximum | May 31, 2012 Maximum Notes Due May 2015 Troms Offshore Supply AS | Jun. 30, 2013 Maximum Senior Notes Due 2019 Troms Offshore Supply AS | Mar. 31, 2015 September 2010 Senior Unsecured Notes USD ($) | Mar. 31, 2014 September 2010 Senior Unsecured Notes USD ($) | Mar. 31, 2011 September 2010 Senior Unsecured Notes USD ($) | Mar. 31, 2015 September 2010 Senior Unsecured Notes Not classified as current maturities of long-term debt USD ($) | Mar. 31, 2015 September 2010 Senior Unsecured Notes Minimum | Mar. 31, 2015 September 2010 Senior Unsecured Notes Maximum | Jul. 31, 2003 July 2003 Senior Unsecured Notes USD ($) | Mar. 31, 2015 July 2003 Senior Unsecured Notes USD ($) | Mar. 31, 2014 July 2003 Senior Unsecured Notes USD ($) | Mar. 31, 2015 July 2003 Senior Unsecured Notes Not classified as current maturities of long-term debt USD ($) | Mar. 31, 2015 July 2003 Senior Unsecured Notes Minimum | Mar. 31, 2015 July 2003 Senior Unsecured Notes Maximum | Nov. 15, 2013 September 2013 Senior Unsecured Notes USD ($) | Sep. 30, 2013 September 2013 Senior Unsecured Notes USD ($) | Mar. 31, 2015 September 2013 Senior Unsecured Notes USD ($) | Mar. 31, 2014 September 2013 Senior Unsecured Notes USD ($) | Sep. 30, 2013 September 2013 Senior Unsecured Notes USD ($) | Mar. 31, 2015 September 2013 Senior Unsecured Notes Minimum | Mar. 31, 2015 September 2013 Senior Unsecured Notes Maximum | Aug. 15, 2011 August 2011 Senior Unsecured Notes USD ($) | Mar. 31, 2015 August 2011 Senior Unsecured Notes USD ($) | Mar. 31, 2014 August 2011 Senior Unsecured Notes USD ($) | Mar. 31, 2015 August 2011 Senior Unsecured Notes Minimum | Mar. 31, 2015 August 2011 Senior Unsecured Notes Maximum
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior note issuable amount under purchase agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 500,000,000 tdw_NotesIssuableInExchangeFaceAmount / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember |  |  |  |  |  |  |
Sale of debt outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 425,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember |  |  |  | 300,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_JulyTwoThousandThreeSeniorUnsecuredNotesMember |  |  |  |  |  | 200,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember | 300,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember | 500,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember |  |  |  |  | 165,000,000 us-gaap_ProceedsFromIssuanceOfUnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_AugustTwoThousandElevenSeniorUnsecuredNotesMember |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 years | 12 years |  |  |  |  | 7 years | 12 years |  |  |  |  |  | 7 years | 12 years |  |  |  | 8 years | 10 years
Consolidated debt to consolidated total capitalization, ratio |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 55.00%tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  | 55.00%tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  | 55.00%tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization / us-gaap_LongtermDebtTypeAxis = tdw_JulyTwoThousandThreeSeniorUnsecuredNotesMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  | 55.00%tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  | 55.00%tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization / us-gaap_LongtermDebtTypeAxis = tdw_AugustTwoThousandElevenSeniorUnsecuredNotesMember / us-gaap_RangeAxis = us-gaap_MaximumMember
Interest coverage ratio |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300.00%tdw_InterestCoverageRatio / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300.00%tdw_InterestCoverageRatio / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |
After-tax loss relating to interest rate hedges |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,800,000 us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember | 2,400,000 us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pre-tax loss relating to interest rate hedges |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,600,000 us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember | 3,700,000 us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate debt outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 425,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember | 425,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember |  | 42,500,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember / us-gaap_StatementScenarioAxis = tdw_ScenarioFiveMember |  |  |  | 35,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_JulyTwoThousandThreeSeniorUnsecuredNotesMember | 35,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_JulyTwoThousandThreeSeniorUnsecuredNotesMember | 35,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_JulyTwoThousandThreeSeniorUnsecuredNotesMember / us-gaap_StatementScenarioAxis = tdw_ScenarioFiveMember |  |  |  |  | 500,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember | 500,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember |  |  |  |  | 165,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_AugustTwoThousandElevenSeniorUnsecuredNotesMember | 165,000,000 us-gaap_UnsecuredDebt / us-gaap_LongtermDebtTypeAxis = tdw_AugustTwoThousandElevenSeniorUnsecuredNotesMember |  |
Debt instrument maturity, month and year |  |  |  |  |  |  |  |  |  |  |  |  | 2015-05 | 2019-06 | 2027-01 | 2026-01 |  |  |  | 2024-05 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2015-12 |  |  |  |  |  | 2015-07 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instruments face amount |  |  |  |  |  |  |  |  |  |  |  |  | 35,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyFifteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 25,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyNineteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 29,500,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 300,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  | 204,400,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Semi-annual principal payments |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,200,000 us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 12,500,000 us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  | 8,500,000 us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument bearing floating interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.91%us-gaap_LongTermDebtPercentageBearingVariableInterestRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  | 2.31%us-gaap_LongTermDebtPercentageBearingVariableInterestRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Indebtedness rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.30%tdw_DebtInstrumentAggregateRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 1.50%tdw_DebtInstrumentAggregateRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  | 1.50%tdw_DebtInstrumentAggregateRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total capitalization rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.21%tdw_CapitalizationRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 3.81%tdw_CapitalizationRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  | 5.38%tdw_CapitalizationRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument outstanding amount | 1,514,870,000 us-gaap_LongTermDebt | 1,534,476,000 us-gaap_LongTermDebt |  |  | 5,600,000 us-gaap_LongTermDebt / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 45,000,000 us-gaap_LongTermDebt / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 5,600,000 us-gaap_LongTermDebt / tdw_DebtInstrumentInterestRateAxis = tdw_FloatingRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 45,000,000 us-gaap_LongTermDebt / tdw_DebtInstrumentInterestRateAxis = tdw_FloatingRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 54,400,000 us-gaap_LongTermDebt / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 436,900,000 us-gaap_LongTermDebt / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 29,500,000 us-gaap_LongTermDebt / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / tdw_DebtOutstandingTypeAxis = tdw_UnitesStatesDollarDenominatedDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  | 29,500,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySevenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  | 34,200,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 275,000,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentySixMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  | 20,200,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 161,900,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument bearing interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.88%us-gaap_LongTermDebtPercentageBearingFixedInterestRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 6.38%us-gaap_LongTermDebtPercentageBearingFixedInterestRate / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyTwentyFourMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyFifteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember / us-gaap_RangeAxis = us-gaap_MinimumMember | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyNineteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  | 3.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyFifteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember / us-gaap_RangeAxis = us-gaap_MaximumMember | 3.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyNineteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument repayment |  |  |  |  |  |  |  |  |  |  |  | 15,000,000 us-gaap_RepaymentsOfDebt / us-gaap_DebtInstrumentAxis = tdw_SeniorNotesDueTwentyFifteenMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument estimated fair value |  |  |  |  |  |  |  |  | 54,100,000 us-gaap_LongTermDebtFairValue / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 435,000,000 us-gaap_LongTermDebtFairValue / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 29,500,000 us-gaap_LongTermDebtFairValue / tdw_DebtInstrumentInterestRateAxis = tdw_FixedRateDebtMember / tdw_DebtOutstandingTypeAxis = tdw_UnitesStatesDollarDenominatedDebtMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt extinguished amount |  |  | 32,500,000 us-gaap_RepaymentsOfSecuredDebt / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 188,900,000 us-gaap_RepaymentsOfSecuredDebt / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 82,100,000 us-gaap_RepaymentsOfSecuredDebt / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 500,000,000 us-gaap_RepaymentsOfSecuredDebt / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayment of bond at average price as a percentage of par value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 105.00%tdw_LongTermDebtAveragePricePercentageOfParValue / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | 105.00%tdw_LongTermDebtAveragePricePercentageOfParValue / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss on early extinguishment of bond | $ (4,144,000)us-gaap_GainsLossesOnExtinguishmentOfDebt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (4,100,000)us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember | (26,000,000)us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_DebtInstrumentAxis = us-gaap_BondsMember / dei_LegalEntityAxis = tdw_TromsOffshoreSupplyAsMember |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Capitalization Rate + References No definition available. + Details
Name: | tdw_CapitalizationRate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Consolidated Debt As Percentage Of Total Capitalization + References No definition available. + Details
Name: | tdw_ConsolidatedDebtAsPercentageOfTotalCapitalization
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument Aggregate Rate + References No definition available. + Details
Name: | tdw_DebtInstrumentAggregateRate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Maturity, Month and Year + References No definition available. + Details
Name: | tdw_DebtInstrumentMaturityMonthAndYear
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- Definition Long Term Debt Average Price Percentage Of Par Value + References No definition available. + Details
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- Definition Notes Issuable In Exchange, Face Amount + References No definition available. + Details
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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
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- Definition Amount of the required periodic payments applied to principal. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 + Details
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- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12317-112629 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12355-112629 + Details
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- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References No definition available. + Details
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- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount before tax, after reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669646-108580 + Details
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- Definition Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=36458714&loc=SL7669646-108580 + Details
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- Definition The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
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- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References No definition available. + Details
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- Definition The cash outflow to repay long-term debt that is wholly or partially secured by collateral. Excludes repayments of tax exempt secured debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 + Details
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- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Article 5 -Subsection 19, 20, 22 + Details
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