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Assumptions Used to Determine Projected and Accumulated Benefit Obligations of Domestic Defined Benefit Pension and Postretirement Benefit Plans (Detail)
Dec. 31, 2014
Dec. 31, 2013
Defined benefit pension plans    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 3.80%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember		 4.70%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Weighted average rate of future compensation increases 3.80%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember		 3.80%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_PensionPlansDefinedBenefitMember
Postretirement benefit plans    
Defined Benefit Plan Disclosure [Line Items]    
Discount rate 3.80%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember		 4.70%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Annual increase in Medicare Part B premium 6.00%mat_AnnualIncreaseInMedicarePartBPremiumUsedToDetermineProjectedAndAccumulatedBenefitObligationsForDomesticPostretirementBenefitPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember		 6.00%mat_AnnualIncreaseInMedicarePartBPremiumUsedToDetermineProjectedAndAccumulatedBenefitObligationsForDomesticPostretirementBenefitPlans
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Projected and Accumulated Benefit Obligations | Pre-65    
Defined Benefit Plan Disclosure [Line Items]    
Health care cost trend rate 7.50%mat_HealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_PriorToAgeSixtyFiveMember		 8.50%mat_HealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_PriorToAgeSixtyFiveMember
Ultimate cost trend rate 4.50%mat_DefinedBenefitPlanUltimateHealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_PriorToAgeSixtyFiveMember		 6.10%mat_DefinedBenefitPlanUltimateHealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_PriorToAgeSixtyFiveMember
Year that the rate reaches the ultimate cost trend rate 2023 2030
Projected and Accumulated Benefit Obligations | Post-65    
Defined Benefit Plan Disclosure [Line Items]    
Health care cost trend rate 8.80%mat_HealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_AfterAgeSixtyFiveMember		 7.50%mat_HealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_AfterAgeSixtyFiveMember
Ultimate cost trend rate 4.50%mat_DefinedBenefitPlanUltimateHealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_AfterAgeSixtyFiveMember		 5.40%mat_DefinedBenefitPlanUltimateHealthCareCostTrendRateUsedToDetermineProjectedAndAccumulatedBenefitObligation
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= mat_ProjectedAndAccumulatedBenefitObligationsMember
/ mat_EventTimingAxis
= mat_AfterAgeSixtyFiveMember
Year that the rate reaches the ultimate cost trend rate 2024 2030