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Schedule of Minimum and Maximum Market Value of Plan Assets (Detail) | 12 Months Ended
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Mar. 31, 2015
Equity Securities |
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items] |
Minimum market value objective for plan assets | 55.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMinimum / us-gaap_InvestmentTypeAxis = us-gaap_EquitySecuritiesMember
Maximum market value objective for plan assets | 75.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMaximum / us-gaap_InvestmentTypeAxis = us-gaap_EquitySecuritiesMember
Debt Securities |
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items] |
Minimum market value objective for plan assets | 25.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMinimum / us-gaap_InvestmentTypeAxis = us-gaap_DebtSecuritiesMember
Maximum market value objective for plan assets | 45.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMaximum / us-gaap_InvestmentTypeAxis = us-gaap_DebtSecuritiesMember
Investment Grade Bonds |
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items] |
Minimum market value objective for plan assets | 0.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMinimum / us-gaap_InvestmentTypeAxis = tdw_InvestmentGradeBondsMember
Maximum market value objective for plan assets | 20.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMaximum / us-gaap_InvestmentTypeAxis = tdw_InvestmentGradeBondsMember
Cash and Cash Equivalents |
Schedule of Pension and Other Postretirment Plan Assets by Fair Value [Line Items] |
Minimum market value objective for plan assets | 0.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMinimum / us-gaap_InvestmentTypeAxis = us-gaap_CashAndCashEquivalentsMember
Maximum market value objective for plan assets | 10.00%us-gaap_DefinedBenefitPlanTargetPlanAssetAllocationsRangeMaximum / us-gaap_InvestmentTypeAxis = us-gaap_CashAndCashEquivalentsMember

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- Definition Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c)(i) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920 + Details
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- Definition Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c)(i) -URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920 + Details
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