XML 1028 R78.htm IDEA: XBRL DOCUMENT v2.4.1.9
Schedule of Minimum and Maximum Market Value of Plan Assets (Detail)
 12 Months Ended
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