 | us-gaap:DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefits |
 | us-gaap:DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefits |
 | us-gaap:DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefits |
 | us-gaap:DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract | parent-child | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefits |
 | us-gaap:DefinedBenefitPlanAssetsExpectedToBeReturnedToEmployerAmount | parent-child | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefits |
 | us-gaap:DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefitsScheduleOfDefinedBenefitPlansDisclosuresTable |
 | us-gaap:DefinedBenefitPlanEstimatedFutureBenefitPaymentsAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefitsScheduleOfDefinedBenefitPlansDisclosuresTable |
 | us-gaap:DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefitsScheduleOfDefinedBenefitPlansDisclosuresTable |
 | us-gaap:DisclosureOfExpectedGrossPrescriptionDrugSubsidyReceiptsAbstract | domain-member | http://fasb.org/us-gaap/role/disclosure/CompensationRelatedCostsRetirementBenefitsScheduleOfDefinedBenefitPlansDisclosuresTable |