HMHC


Line plots across dimensions of each concept
Line plots across concepts
Tables

Table of contents



us-gaap:CommonStockValue

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization

us-gaap:CostOfGoodsAndServicesSold

us-gaap:GainLossOnInvestments

us-gaap:GainsLossesOnExtinguishmentOfDebt

us-gaap:GrossProfit

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxesPaidNet

us-gaap:InterestExpense

us-gaap:InterestIncomeOperating

us-gaap:InterestPaidNet

us-gaap:LitigationSettlementExpense

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:OperatingIncomeLoss

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax
us-gaap:DerivativeInstrumentRisk

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:ProfitLoss

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:ProductOrService
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:SellingGeneralAndAdministrativeExpense

us-gaap:Assets
us-gaap:StatementBusinessSegments

us-gaap:Liabilities

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:AccountsReceivableNetCurrent

us-gaap:InventoryNet

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:MachineryAndEquipmentGross

us-gaap:NoncurrentAssets
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:LeaseholdImprovementsGross

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AmortizationOfIntangibleAssets
us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:LongTermInvestments

us-gaap:Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OtherAssetsNoncurrent

us-gaap:AccountsPayableCurrent

us-gaap:LiabilitiesCurrent

us-gaap:LongTermDebtCurrent

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OtherLiabilitiesCurrent

us-gaap:LongTermDebt
us-gaap:DebtInstrument
us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
us-gaap:LongtermDebtType

us-gaap:LongTermDebtNoncurrent

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:OperatingLeaseLiability

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:RetainedEarningsAccumulatedDeficit
us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:AdjustmentsForNewAccountingPronouncements

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:TreasuryStockValue

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInInventories

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:ProfitLoss

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:RepaymentsOfLongTermDebt

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxAssetsNet

us-gaap:UnrecognizedTaxBenefits

us-gaap:DeferredTaxAssetsValuationAllowance

hmhc:AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan
us-gaap:StatementEquityComponents

hmhc:AmortizationAndImpairmentsOfOperatingLeaseAssets

hmhc:AmortizationOfFilmAsset

hmhc:AmortizationOfOtherIntangibleAssets

hmhc:AmortizationOfPrePublicationCosts

hmhc:ContractWithCustomerAssetsNetPercentChange

hmhc:ContractWithCustomerLiabilitiesNetPercentChange

hmhc:DebtEquityOfferingCost
us-gaap:LongtermDebtType
hmhc:DebtInstrumentPercentageOfPrincipalForSubjectToPrepaymentPremium
us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
hmhc:DebtInstrumentRepaid
us-gaap:Range, us-gaap:CreditFacility
hmhc:DebtInstrumentsFixedChargeCoverageRatio

hmhc:IncomeFromTransitionServicesAgreement

hmhc:IncreaseDecreaseInContractAssetsAndLiabilities

hmhc:IncreaseDecreaseInOperatingLeaseLiabilities

hmhc:PaymentsForAdditionsToPrepublicationCost

hmhc:SegmentAdjustedEbitda
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:AdjustmentForAmortization

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs

us-gaap:AmortizationOfDeferredSalesCommissions

us-gaap:AmortizationOfFinancingCostsAndDiscounts

us-gaap:AssetImpairmentCharges
us-gaap:FairValueByAssetClass

us-gaap:CapitalizedContractCostAmortization

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations

us-gaap:ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized

us-gaap:ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueModificationOfContract
us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

us-gaap:DeferredIncomeTaxesAndTaxCredits
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanInterestCost
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanServiceCost

us-gaap:Depreciation

us-gaap:DepreciationAndAmortization
us-gaap:Range, us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

us-gaap:GainLossOnDerivativeInstrumentsNetPretax
us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType
us-gaap:GainLossOnDispositionOfIntangibleAssets

us-gaap:GoodwillImpairmentLoss

us-gaap:ImpairmentOfLongLivedAssetsHeldForUse

us-gaap:IncomeLossFromContinuingOperationsPerBasicAndDilutedShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInOtherOperatingAssets

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations

us-gaap:IncreaseDecreaseInRestructuringReserve

us-gaap:IncreaseDecreaseInRoyaltiesPayable

us-gaap:InterestPaidDiscontinuedOperations

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations

us-gaap:NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1
us-gaap:FairValueByAssetClass
us-gaap:NoncashOrPartNoncashAcquisitionPayablesAssumed1
us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
us-gaap:NotesReduction

us-gaap:OperatingLeaseImpairmentLoss

us-gaap:OperatingLeaseRightOfUseAssetAmortizationExpense
us-gaap:DerivativeInstrumentRisk
us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax
us-gaap:DerivativeInstrumentRisk, us-gaap:SubsequentEventType

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
us-gaap:RestructuringCostAndReserve
us-gaap:PaymentsForRestructuring
us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
us-gaap:RestructuringPlan

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:PensionAndOtherPostretirementBenefitContributions
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:ProceedsFromDivestitureOfBusinesses
us-gaap:StatementScenario, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromLinesOfCredit
us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType
us-gaap:ProceedsFromSaleOfIntangibleAssets
us-gaap:ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmount
us-gaap:QuantifyingMisstatementInCurrentYearFinancialStatementsAmount

us-gaap:RelatedPartyTransactionAmountsOfTransaction

us-gaap:RepaymentsOfLinesOfCredit
us-gaap:RestructuringPlan
us-gaap:RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent

us-gaap:RestructuringCharges
us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
us-gaap:RestructuringPlan
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross
us-gaap:ValuationAllowancesAndReservesType
us-gaap:ValuationAllowancesAndReservesPeriodIncreaseDecrease

hmhc:ContingentLiabilityRelatedToSuretyBond

hmhc:ContractWithCustomerDeferredSalesCommission

hmhc:DeferredTaxAssetOperatingLossCarryforwardsAndOtherCarryforwards

hmhc:DeferredTaxAssetsDeferredInterest

hmhc:DeferredTaxAssetsOperatingLeaseLiabilities

hmhc:DeferredTaxLiabilitiesDefiniteLivedIntangibleAssets

hmhc:DeferredTaxLiabilitiesDepreciationAndAmortization

hmhc:DeferredTaxLiabilitiesIndefiniteLivedIntangibleAssets

hmhc:DeferredTaxLiabilitiesOperatingLeaseAssets

hmhc:DefinedBenefitPlanUnfundedStatusOfPlan
us-gaap:RetirementPlanType
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedRoyaltiesCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedSalariesAndWagesCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
hmhc:DisposalGroupIncludingDiscontinuedOperationAdvanceRoyaltiesNetCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
hmhc:DisposalGroupIncludingDiscontinuedOperationPrepublicationCostsNetCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
hmhc:DisposalGroupIncludingDiscontinuedOperationSubjectToCustomaryWorkingCapitalAdjustmentExpectedPayment

hmhc:FilmAndMediaGross

hmhc:NonFinancialAssetsFairValueDisclosure
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel

hmhc:OperatingLossCarryForwardsReducedReserveOfUncertainTaxPositions
us-gaap:RestructuringPlan, us-gaap:RetirementPlanType
hmhc:PercentageOfEmployeeBaseEligibleToParticipateInVoluntaryRetirementProgram

hmhc:PercentageOfRevenueRecognitionFromContractsWithCustomers

hmhc:PrePublicationCostsNet

hmhc:TotalLeaseAssets

hmhc:UnrecognizedTaxBenefitsExcludingInterestAndPenalties

us-gaap:AccountsReceivableGross

us-gaap:AccountsReceivableNet

us-gaap:AccruedRoyaltiesCurrent

us-gaap:AccruedSalariesCurrent

us-gaap:AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax
us-gaap:RegulatoryLiability
us-gaap:RetirementPlanType

us-gaap:AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax

us-gaap:AdvanceRoyaltiesNoncurrent

us-gaap:AllowanceForDoubtfulAccountsReceivable
us-gaap:ValuationAllowancesAndReservesType

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AssetsFairValueDisclosure
us-gaap:FairValueByAssetClass
us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:BuildingsAndImprovementsGross
us-gaap:FairValueByAssetClass
us-gaap:CapitalLeasesFutureMinimumPaymentsDueCurrent

us-gaap:CapitalizedComputerSoftwareGross

us-gaap:CapitalizedContractCostNet

us-gaap:ContractWithCustomerAssetNet

us-gaap:ContractWithCustomerLiability

us-gaap:DebtInstrumentCarryingAmount
us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentFaceAmount

us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredLongTermLiabilityCharges

us-gaap:DeferredRevenueCurrent

us-gaap:DeferredTaxAssetsInProcessResearchAndDevelopment

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesOtherComprehensiveIncome

us-gaap:DefinedBenefitPensionPlanCurrentAndNoncurrentLiabilities

us-gaap:DefinedBenefitPensionPlanLiabilitiesCurrent

us-gaap:DefinedBenefitPensionPlanLiabilitiesNoncurrent
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax
us-gaap:RegulatoryLiability
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax
us-gaap:RegulatoryLiability
us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

us-gaap:DefinedBenefitPlanBenefitObligation
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FinancialInstrument
us-gaap:FinancialInstrument
us-gaap:RetirementPlanType
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation
us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage
us-gaap:RetirementPlanType
us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1
us-gaap:DefinedBenefitPlanByPlanAssetCategories
us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations
us-gaap:DerivativeInstrumentRisk
us-gaap:DerivativeNotionalAmount
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent
us-gaap:AwardType
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions

us-gaap:FinanceLeaseRightOfUseAsset

us-gaap:FinancialLiabilitiesFairValueDisclosure
us-gaap:FairValueByFairValueHierarchyLevel
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass
us-gaap:FairValueByLiabilityClass

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
us-gaap:FiniteLivedIntangibleAssetsGross

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss

us-gaap:GuaranteeObligationsMaximumExposure

us-gaap:IntangibleAssetsGrossExcludingGoodwill

us-gaap:InterestPayableCurrent

us-gaap:InventoryFinishedGoodsNetOfReserves

us-gaap:InventoryRawMaterialsNetOfReserves

us-gaap:InventoryWorkInProcessNetOfReserves

us-gaap:LandAndLandImprovements

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:LettersOfCreditOutstandingAmount

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent
us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations
us-gaap:CreditFacility, us-gaap:SubsequentEventType
us-gaap:LineOfCredit
us-gaap:DebtInstrument
us-gaap:LongTermDebtFairValue
us-gaap:LongtermDebtType

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent
us-gaap:StatementGeographical, us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards

us-gaap:OtherIntangibleAssetsNet

us-gaap:OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent

us-gaap:PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForLetterOfCreditFacilities

us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount
us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan
us-gaap:RestructuringReserve
us-gaap:RestructuringPlan

us-gaap:RestructuringReserveCurrent
us-gaap:RestructuringPlan
us-gaap:AwardType
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1

us-gaap:SupplementalUnemploymentBenefitsSeveranceBenefits
us-gaap:IncomeTaxAuthority
us-gaap:TaxCreditCarryforwardAmount
us-gaap:IncomeTaxAuthority, us-gaap:TaxCreditCarryforward
us-gaap:StatementGeographical, us-gaap:TaxCreditCarryforward
us-gaap:TaxCreditCarryforward

us-gaap:ValuationAllowancesAndReservesBalance
us-gaap:ValuationAllowancesAndReservesType

Plots across concepts


IncomeStatement
Other Comprehensive Income Loss Net Of Tax
Expenses
Income Tax Expense Benefit
Balance Sheet
Operating Lease Right Of Use Asset
Assets
Property Plant And Equipment Net
Current Assets
Prepaid Expense And Other Assets Current
NonCurrent Assets
Deferred Income Tax Assets Net
PropertyPlantAndEquipmentNet
Property Plant And Equipment Net
Liabilities
Operating Lease Liability
Current Liabilities
Operating Lease Liability Current
Noncurrent Liabilities
Other Liabilities Noncurrent
Stockholders Equity
Retained Earnings Accumulated Deficit
CashFlow
Net Cash Provided By Used In Financing Activities
NetCashProvidedByUsedInOperatingActivities
Increase Decrease In Inventories
NetCashProvidedByUsedInInvestingActivities
Payments To Acquire Property Plant And Equipment
NetCashProvidedByUsedInFinancingActivities
Net Cash Provided By Used In Financing Activities
Shares
Weighted Average Number Of Share Outstanding Basic And Diluted
OperatingLeaseLiability
Operating Lease Liability Current
LesseeOperatingLeaseLiabilityPaymentsDue
Lessee Operating Lease Liability Payments Due Next Twelve Months
InventoryNet
Inventory Work In Process Net Of Reserves
AccountsReceivable
Allowance For Doubtful Accounts Receivable Current

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:CommonStockValue ██▅▅▅▅▃▃▃▃▂▂▁▁▁▁▁▁1.5221.521.5051.5041.5011.51.4891.4891.4871.4871.4811.4811.481.4791.4791.4791.4781.477
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding 130.350602NANA125.799018125.458566124.688974NA124.807488124.147961123.798641NA123.87038123.423911123.222353NA123.243351122.919853122.777615
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic 127.500256NANA125.799018125.458566124.688974NA124.315491124.147961123.798641NA123.553116123.423911123.222353NA123.03878122.919853122.777615
us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted NA126.473317NANA125.458566124.688974NANA124.147961123.798641NANA123.423911NANANANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities us-gaap:EmployeeStockOption▁█1.7448491.882212NA1.9472122.3136122.349112NA3.1150133.1289263.488212NA3.5011653.4307493.465749NA3.4204273.3052583.132844
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities us-gaap:RestrictedStockUnitsRSUNA4.159106NA5.0600634.5699143.243031NA1.8203564.1136552.993508NA0.610793.2278122.12862NA0.2621581.7228331.085069
us-gaap:EarningsPerShareBasic 1.71NA-0.66-0.1-0.3-2.77-1.010.56-0.33-0.95-0.450.7-0.19-0.82-0.210.74-0.38-0.98
us-gaap:EarningsPerShareDiluted 1.68NA-0.66-0.1-0.3-2.77-1.010.55-0.33-0.95-0.450.7-0.19-0.82-0.210.73-0.38-0.98
us-gaap:EarningsPerShareBasicAndDiluted NA-0.41NANA-0.3-2.77NANA-0.33-0.95NANA-0.19-0.82NANANANA
us-gaap:IncomeLossFromContinuingOperationsPerBasicShare 1e-08NANANA-2.5e-07NANA5.6e-07-3.3e-07NA-7e-076.800000000000001e-07-2.4e-07-8.6e-07-2.9e-077.2e-07-4.0000000000000003e-07-1.01e-06
us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare 2e-08NANANA-2.5e-07NANA5.5e-07-3.3e-07NA-7e-076.800000000000001e-07-2.4e-07-8.6e-07-2.9e-077.2e-07-4.0000000000000003e-07-1.01e-06
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
 TTM Greenblatt ROC _ _▇▆▅▇▆▁▅█▆▅▅█▆▅▅█▆▅22.834-37.3-68.9730.272-22.212-338.176-108.94777.871-30.253-101.835-74.71191.838-8.956-86.549-76.46290.21-31.166-96.103
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:ComprehensiveIncomeNetOfTax █▅▄▅▅▁▄▆▅▄▅▆▅▄▅▆▅▄219.932-45.393-92.318-12.38-37.175-346.417-123.07668.652-42.585-118.912-60.36986.925-21.783-97.59-21.18491.376-47.247-119.359
us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization ▃▁▃▆▃▂▄█▆▂▃▆▅124.3658.137100.677182.767124.3690.012134.695246.527190.83196.055119.928201.748160.058NANANANANA
us-gaap:CostOfGoodsAndServicesSold ▃▁▃▆▄▂▄█▆▃▃▆▅▃▄▆▅153.35586.354137.575219.175160.827126.475182.41292.187232.841136.742157.375238.08201.759135.444161.938245.153216.318NA
us-gaap:GainLossOnInvestments 0.836NA0.3531.738NANANA-0.27NANANANANANANANANANA
us-gaap:GainsLossesOnExtinguishmentOfDebt -12.505NANANANANANANANANANANANANANANANANA
us-gaap:GrossProfit NANA65.986167.41590.38963.4559.065273.481156.05557.89391.663278.175162.82764.31589.692277.602176.73373.406
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▇▆▅▆▆▁▅█▆▅▅█▆▅▅█▆▅2.149-46.718-84.659-13.633-39.438-354.512-125.17366.658-40.21-110.907-82.89780.559-21.088-96.607-86.49779.888-40.747-106.266
us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest ▇▆▅▆▆▁▅█▆▅▅█▆▅▆█▆▅2.158-49.028-83.145-12.552-38.168-345.973-125.11869.26-40.613-117.362-86.3983.908-29.089-105.886-36.44688.636-48.666-123.861
us-gaap:IncomeTaxExpenseBenefit ▇▇▇▇▇▆▇▆▇▇▇▆▇▇▁▆▇█-0.0092.31-1.514-1.081-1.27-8.539-0.055-2.6020.4036.4553.493-3.3492.1844.704-60.329-10.6186.1214.392
us-gaap:IncomeTaxesPaidNet NANA0.0351.80.0470.0010.2020.0640.3920.013-0.1150.781-0.008-0.228NANA0.6030.023
us-gaap:InterestExpense ▂▁▆▇█▇▅▃▄▃▃▃▃▃▃▃▂▂9.9858.56415.52616.16817.48216.78313.63611.59711.96311.58211.64511.62711.47210.93611.46610.69910.43210.208
us-gaap:InterestIncomeOperating ▁▁▁▁▁▄▇▃▁▆█▂▁▃▄▂▁▂0.0140.020.0260.0320.0750.7661.4590.5090.0971.0921.650.2770.1170.5060.6970.2810.1150.245
us-gaap:InterestPaidNet ▁▆▃█▄▆▄▄▅▄▄▄▄▄▄▄0.87114.7467.02921.3729.18815.3538.79510.32711.22210.71510.89310.55210.4719.8429.6699.667NANA
us-gaap:LitigationSettlementExpense 2.5NANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLoss █▅▄▅▅▁▄▆▅▄▅▆▅▄▅▆▅▄218.628-51.983-83.145-12.552-38.168-345.973-125.11869.26-40.613-117.362-55.92186.349-23.272-101.311-26.16890.506-46.867-120.658
us-gaap:OperatingIncomeLoss ▇▆▅▇▆▁▅█▆▅▅█▆▅▅█▆▅22.834-37.3-68.9730.272-22.212-338.176-108.94777.871-30.253-101.835-74.71191.838-8.956-86.549-76.46290.21-31.166-96.103
us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax NANA0.00.2581.06-0.3310.275-0.257-2.077-1.327-2.2530.686NANANANANANA
 us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax us-gaap:DerivativeInstrumentRisk us-gaap:InterestRateContractNANANA0.30.40.30.3-0.3-4.71.3-2.3NANANANANANANA
us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax ▃▁▆▄▄▄▅▁▇▂▄▄▄█▆▆▆▅-0.218-0.3350.036-0.086-0.067-0.113-0.033-0.3510.105-0.232-0.143-0.097-0.1430.2270.0380.0690.062-0.06
us-gaap:OtherComprehensiveIncomeLossNetOfTax ▁█1.3046.59NA0.1720.993-0.444NA-0.608-1.972-1.55NA0.5761.4893.7214.9840.87-0.381.299
us-gaap:ProfitLoss █▅▄▅▅▁▄▆▅▄▅▆▅▄▅▆218.628-51.983-83.145-12.552-38.168-345.973-125.11869.26-40.613-117.362-55.92186.349-23.272-101.311-26.16890.506NANA
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▄▁▂▅▃▂▃█▅▂▃▇▅▂▂▇▅▂308.672146.195203.561386.59251.216189.925241.475565.668388.896194.635249.038516.255375.581199.759233.745516.206393.051203.685
us-gaap:SellingGeneralAndAdministrativeExpense ▃▁▃▄▂▄▅█▇▅▆▇▇▅▆▇▆▆114.76789.235111.095127.324106.329133.353146.4188.957175.266151.983158.243176.202174.152150.534154.239178.104166.165156.352
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:Assets ▁▁▂▄▃▃▆█▆▅▆▇▆▅▆▇▆▆1857.8951900.4672021.1262206.3282166.372195.4062513.1722824.792616.2712461.4652495.1242631.5522524.3562458.1122563.5912719.6322583.9942568.067
us-gaap:Liabilities ▁▄▅▇▆▆▆█▆▄▃▄▄▃▃▅▅▄1586.5911852.0791930.6632026.2841977.4851971.4461946.8122138.0972002.6661808.7941726.6541806.4411790.0971705.1331768.3981906.0031865.1491804.648
us-gaap:LiabilitiesAndStockholdersEquity ▁▁▂▄▃▃▆█▆▅▆▇▆▅▆▇▆▆1857.8951900.4672021.1262206.3282166.372195.4062513.1722824.792616.2712461.4652495.1242631.5522524.3562458.1122563.5912719.6322583.9942568.067
us-gaap:StockholdersEquity ▃▁▁▂▂▃▆▇▆▆▇█▇▇██▇▇271.30448.38890.463180.044188.885223.96566.36686.693613.605652.671768.47825.111734.259752.979795.193813.629718.845763.419
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:AssetsCurrent ▂▃▃▅▄▄▄█▅▂▄▆▂▁▃▅▃▂585.541605.244620.926752.756672.737682.042713.094974.051737.348550.186706.278807.992567.726496.961621.099770.326607.086563.638
us-gaap:CashAndCashEquivalentsAtCarryingValue ▄▅▇▇▄▇██▁▂▇▃▁▃▄▄▃▄146.541170.901281.2271.543138.824254.665296.353308.67615.11474.185253.365104.30430.70998.664148.979133.9878.735149.54
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▄▅▇▇▄▇██▁▂▇▃▁▃▄▄▃146.541170.901281.2271.543138.824254.665296.353308.67615.11474.185253.365104.30430.70998.664148.979133.9878.735NA
us-gaap:AccountsReceivableNetCurrent ▅▁▂▅▅▂▃██▃▃▆▅▂▃▇▅▃266.73992.477152.832282.179273.168139.981184.425434.903432.082183.125203.574353.075293.693164.435201.08382.726304.301167.194
us-gaap:InventoryNet ▁▃▂▃▆█▅▅██▃▂▅▅▂▂▄▅145.027175.79166.963175.82237.226265.364213.059211.744267.77261.924184.209170.012212.436206.444154.644156.567197.903209.105
us-gaap:PrepaidExpenseAndOtherAssetsCurrent ▆▅▃▅▅▄▃▃▄▄▁▅█▆█▄▆▅27.23425.10519.93123.21423.51922.03219.25718.72822.38220.95315.29725.2630.88827.41829.94721.03126.14723.339
us-gaap:MachineryAndEquipmentGross NANA14.985NANANA12.97NANANA11.63NANANA31.843NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NoncurrentAssets 2.0NA0.228NANANA0.113NANANA0.064NANANA7.593NANANA
us-gaap:PropertyPlantAndEquipmentGross NANA726.222NANANA671.494NANANA626.373NANANA609.802NANANA
us-gaap:LeaseholdImprovementsGross NANA24.266NANANA22.974NANANA22.171NANANA23.652NANANA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment NANA633.02NANANA571.106NANANA500.448NANANA455.896NANANA
us-gaap:AmortizationOfIntangibleAssets ▁▁▂▂▂▃▃▃▃▄▅▅▅▆▆▆▆█2.4893.1664.7614.7614.7095.8256.346.3416.2717.6058.2378.2388.14810.0910.98610.98710.86713.398
us-gaap:PropertyPlantAndEquipmentNet ▁▁▂▂▂▃▂▃▃▄▅▆▆▆▇▇▇█82.38686.24893.20295.265100.925101.692100.388104.718108.332116.095125.925143.04149.137150.648153.906153.001157.083169.273
us-gaap:LongTermInvestments █▆▆▁5.24.44.42.3NANA4.0NANANANANANANANANANANA
us-gaap:Goodwill ▁▁▁▁▁▁▇▇▇▇▇▇██████437.977437.977437.977454.977454.977454.977716.977716.977716.977716.845716.073713.073783.073783.073783.073783.073783.073783.073
us-gaap:IntangibleAssetsNetExcludingGoodwill ▁▂▄▅▆▆▇█381.054391.412428.584440.111451.146462.127474.225486.356NANA520.892NANANANANANANA
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass hmhc:PublishingRights▁▂▂▃▄▅▇█13.90816.39720.51825.27930.0434.74940.57446.914NANA67.13175.36883.60691.754101.844112.83123.817134.684
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass us-gaap:CustomerRelatedIntangibleAssets▁▂▃▄▅▆▇█129.568132.466136.546139.496142.154144.812147.469150.55NANA156.718160.696164.678168.639172.79174.995177.784183.506
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass us-gaap:OtherIntangibleAssetsNANA136.546NANANA147.469NANANA156.718NANANA172.79NANANA
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass us-gaap:TrademarksAndTradeNames▁▁▃▃▄▄▄▄▄▅▅▅▇▇▇███76.57881.549110.52114.336117.952121.566125.182127.892130.609133.326136.043138.76168.849171.939175.029178.12182.579184.985
 us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass,us-gaap:SubsequentEventType us-gaap:OtherIntangibleAssets,us-gaap:SubsequentEventNANANANANANANANANANANANANANANANANANA
us-gaap:OperatingLeaseRightOfUseAsset ▁▂▃▄▅▅▅▅▆█119.113123.565126.85129.154132.065135.087132.247135.298138.755144.695NANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▇▅▇▇█▅▆▆▄▄▄▅▅▃▂▁▂▁35.12829.99134.87934.72638.72729.96131.4931.69828.53827.1828.42828.93828.65823.56419.89118.37121.81319.598
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:AccountsPayableCurrent ▁▁▁▃▃▄▂▅▇█▄▅▆█▂▆▅▆45.78947.33649.10471.51265.64773.21752.12888.091108.528115.76276.31387.88194.92120.46161.50295.73791.95399.446
us-gaap:LiabilitiesCurrent ▄▃▅█▇█▅▇▆▁▂▅▅▁▃▅▃▁522.179507.926551.821612.858593.371620.137555.15596.58583.388456.931487.692547.598539.347455.846504.229557.334512.177464.235
us-gaap:LongTermDebtCurrent NA19.019.019.019.019.019.08.08.08.08.08.08.08.08.08.08.08.0
us-gaap:OperatingLeaseLiabilityCurrent ▃▃▂▂▂▂▁▄▆█10.499.9489.6699.3399.2319.1718.68511.13512.47914.326NANANANANANANANA
us-gaap:OtherLiabilitiesCurrent █▁▂▂▂▂▂▄▂▁▂▂▃▁▁▃▅▂52.64323.46824.97326.38327.87627.04424.32534.47325.43122.01826.64928.01130.37823.57922.78831.70338.21925.572
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:LongTermDebt ▁██████316.611640.319643.692647.066650.427653.8657.187NANANA772.0NANANA780.0NANANA
us-gaap:LongTermDebtNoncurrent ▁▆▆▆▆▆▆███████████316.611621.319624.692628.066631.427634.8638.187752.241753.377754.513755.649756.785757.922759.058760.194761.33762.466763.602
us-gaap:DeferredIncomeTaxLiabilitiesNet ▄▅▁▅█18.28518.50316.41118.78720.376NA30.871NANANANANANANANANANANA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent NANA16.566NANANA15.113NANANA14.3NANANA20.285NANANA
us-gaap:OtherLiabilitiesNoncurrent ▁▁▂▂▂▃▃▃▃▃▆██▇▇▇▇█0.1050.1522.4193.5023.4935.0496.0286.7466.585.7817.11822.56721.36419.03818.19219.66420.87922.196
us-gaap:OperatingLeaseLiabilityNoncurrent ▄▁▂▃▄▅▄▅▇█134.292129.269132.014133.214135.42137.676134.994137.375140.062142.441NANANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo NANA25.395NANANANA27.03927.06526.91626.889NANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree NANA27.838NANANANA25.83825.86325.7126.118NANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour NANA29.034NANANANA23.42623.4523.30424.549NANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive NANA28.37NANANANA25.2325.25325.22627.469NANANANANANANA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive NANA110.993NANANANA161.79161.825161.774171.203NANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:StockholdersEquity ▃▁▁▂▂▃▆▇▆▆▇█▇▇██▇▇271.30448.38890.463180.044188.885223.96566.36686.693613.605652.671768.47825.111734.259752.979795.193813.629718.845763.419
us-gaap:CommonStockValue ██▅▅▅▅▃▃▃▃▂▂▁▁▁▁▁▁1.5221.521.5051.5041.5011.51.4891.4891.4871.4871.4811.4811.481.4791.4791.4791.4781.477
us-gaap:AdditionalPaidInCapitalCommonStock ██▇▇▆▆▆▅▅▄▄▃▃▂▂▂▁▁4924.8274921.8454918.5424915.8064912.274910.1714906.1654903.4224898.9884895.5564893.1744889.4464885.524882.4584879.7934877.0454873.6384870.966
us-gaap:RetainedEarningsAccumulatedDeficit ▃▁▁▂▂▃▆▇▆▆▇█▇▇██▇█-4089.185-4307.813-4255.83-4172.685-4160.133-4121.965-3775.992-3650.874-3720.134-3679.608-3562.971-3507.05-3593.399-3570.127-3521.527-3495.359-3585.865-3538.998
 us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:CumulativeEffectPeriodOfAdoption,us-gaap:AdjustmentsForNewAccountingPronouncements srt:CumulativeEffectPeriodOfAdoptionAdjustment,us-gaap:AccountingStandardsUpdate201602NANA0.8NANANANANANANANANANANANANANANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax ▅▄▁▅▅▅▅▄▄▅▆██▇▅▃▃▃-47.83-49.134-55.724-46.551-46.723-47.716-47.272-49.314-48.706-46.734-45.184-40.736-41.312-42.801-46.522-51.506-52.376-51.996
us-gaap:TreasuryStockValue ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03518.03
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue █▁2.9722.682NA2.9692.1013.386NA3.7353.6043.442NA3.23.0822.873NANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▂▄▆▃▁▅█▂▁▄▆▂▂▄▅-9.797-81.25640.082264.442-32.509-156.767127.603393.297-89.862-176.06371.448207.281-67.128-96.68696.879178.453NANA
us-gaap:NetCashProvidedByUsedInInvestingActivities █▃▃▂▂▂▂▂▂▃▄▂▂▄▂▁324.457-24.703-25.675-27.388-28.582-30.626-31.241-35.683-27.676-1.7275.887-82.248-48.80748.763-79.88-121.905NANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▆▆▄▅█▄▅▇▆▆▅▇▆▆▆-339.02-4.34-4.75-104.335-54.75145.705-108.685-64.05258.467-1.3971.726-51.43847.98-2.392-2.0-1.303NANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect ▃▂▄▆▂▃▃█▃▁▆▅▃▃▄▄-24.36-110.2999.657132.719-115.841-41.688-12.323293.562-59.071-179.18149.06173.595-67.955-50.31514.99955.245NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:IncreaseDecreaseInAccountsReceivable ▇▅▃▅▆▄▁▅█▄▂▅▆▄▂▆▆▄159.1723.647-129.3479.011133.187-44.444-250.4782.821248.957-20.482-149.50167.893129.258-36.645-181.64678.425137.107-48.812
us-gaap:IncreaseDecreaseInInventories ▃▆▄▁▃▇▄▁▄█▅▂▄▇▄▂▄▆-30.76330.238-8.857-61.406-28.13852.3051.315-56.0265.84677.71514.198-38.4755.99251.8-1.923-41.336-11.20246.69
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▂▄▆▃▁▅█▂▁▄▆▂▂▄▅-9.797-81.25640.082264.442-32.509-156.767127.603393.297-89.862-176.06371.448207.281-67.128-96.68696.879178.453NANA
us-gaap:NetIncomeLoss █▅▄▅▅▁▄▆▅▄▅▆▅▄▅▆▅▄218.628-51.983-83.145-12.552-38.168-345.973-125.11869.26-40.613-117.362-55.92186.349-23.272-101.311-26.16890.506-46.867-120.658
us-gaap:ProfitLoss █▅▄▅▅▁▄▆▅▄▅▆▅▄▅▆218.628-51.983-83.145-12.552-38.168-345.973-125.11869.26-40.613-117.362-55.92186.349-23.272-101.311-26.16890.506NANA
us-gaap:ShareBasedCompensation ▄▃▄▅▁▆▄█▇▇█▆▅▄▄▃▄▃2.9432.6072.8223.1122.1633.4762.8743.8353.7083.5513.8853.3023.1992.9232.8072.5462.9312.544
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInInvestingActivities █▃▃▂▂▂▂▂▂▃▄▂▂▄▂▁324.457-24.703-25.675-27.388-28.582-30.626-31.241-35.683-27.676-1.7275.887-82.248-48.80748.763-79.88-121.905NANA
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▂▂▇▃▄▄▃▂▁▃▄█▅▄█▆▂█9.1099.94915.66510.91712.48311.87510.2118.9927.98310.37512.25316.58712.66112.2417.18214.5789.36417.17
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▆▆▄▅█▄▅▇▆▆▅▇▆▆▆-339.02-4.34-4.75-104.335-54.75145.705-108.685-64.05258.467-1.3971.726-51.43847.98-2.392-2.0-1.303NANA
us-gaap:RepaymentsOfLongTermDebt ▄▁▁▁▁▁█▁▁▁▁▁▁▁▁▁▁▁337.2814.754.754.754.754.75766.02.02.02.02.02.02.02.02.02.02.02.0
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1522000.01520000.01505000.01504000.01501000.01500000.01489000.01489000.01487000.01487000.01481000.01481000.01480000.01479000.01479000.01479000.01478000.01477000.01475000.01474000.01466000.01462000.01456000.01348000.01359000.01432000.01420000.01400000.01400000.01400000.01400000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.10.10.00.00.00.10.00.00.00.10.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-30
Value13012512512412412412312312312312312212212312212213913914214314313914069
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-30
Value12712512512412412412312312312312312212212212212213513914214014013913969
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Share Outstanding Basic And Diluted

us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted

us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted


Weighted
Period End2021-03-312020-06-302020-03-312019-06-302019-03-312018-06-302014-03-312013-03-31
Value126125124124123123139139
Percentage of WeightedAverageNumberOfShareOutstandingBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EmployeeStockOption


Antidilutive
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-31
Value1.7448491.8822121.9472122.3136122.3491123.1150133.1289263.4882123.5011653.4307493.4657493.4204273.3052583.1328441.4331787.1674517.1927820.0886969.29291310
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedStockUnitsRSU


Antidilutive
Period End2021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-06-302015-03-312014-03-31
Value4.1591065.0600634.5699143.2430311.8203564.1136552.9935080.610793.2278122.128620.2621581.7228331.0850690.1461831.1262980.6933310.8308120.3828010.296752
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount221.0259.9197.5138.158.4131.585.817.494.161.47.752.134.610.215.79.68.93.80.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value1.71-0.66-0.1-0.3-2.77-1.010.56-0.33-0.95-0.450.7-0.19-0.82-0.210.74-0.38-0.98-1.480.74-0.23-1.34-0.720.97-0.06-1.12-0.590.760.08-1.05-0.460.75-0.2
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value1.68-0.66-0.1-0.3-2.77-1.010.55-0.33-0.95-0.450.7-0.19-0.82-0.210.73-0.38-0.98-1.480.73-0.23-1.34-0.720.94-0.06-1.12-0.590.750.08-1.05-0.460.75-0.2
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Basic And Diluted

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:EarningsPerShareBasicAndDiluted


Earnings
Period End2021-03-312020-06-302020-03-312019-06-302019-03-312018-06-302018-03-312014-03-312013-03-31
Value-0.41-0.3-2.77-0.33-0.95-0.19-0.82-1.05-0.98
Percentage of EarningsPerShareBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Basic Share

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare

us-gaap:IncomeLossFromContinuingOperationsPerBasicShare


Income
Period End2021-06-302020-06-302019-09-302019-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.01-0.250.56-0.33-0.70.68-0.24-0.86-0.290.72-0.4-1.01
Percentage of IncomeLossFromContinuingOperationsPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Income Loss From Continuing Operations Per Diluted Share

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare

us-gaap:IncomeLossFromContinuingOperationsPerDilutedShare


Income
Period End2021-06-302020-06-302019-09-302019-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.02-0.250.55-0.33-0.70.68-0.24-0.86-0.290.72-0.4-1.01
Percentage of IncomeLossFromContinuingOperationsPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


Comprehensive
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value219-45.393-92.318-12.38-37.175-346.417-123.07668-42.585-118.912-60.36986-21.783-97.59-21.18491-47.247-119.359-185.24889-31.499-171.069-103.962127-7.925-160.949-99.43710614-146.123-56.432105-13.998-138.139
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1570942.9-226965.00.0-38687.5-49566.7-45224.20.013487.6-43902.1-10889.40.031380.9-18617.9-19286.60.032518.1-41084.3-48718.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Cost Of Goods And Service Excluding Depreciation Depletion And Amortization

us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization

us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value124581001821249013424619096119201160
Percentage of CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating888285.7290685.00.0571146.9165813.311750.90.048433.6196733.08796.20.072833.2136801.7

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value15386137219160126182292232136157238201135161245216
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1095392.9431770.00.0684921.9214436.016511.10.057404.1240042.312522.20.085949.5172443.626767.60.087243.1188102.6

Gain Loss On Investments

us-gaap:GainLossOnInvestments

us-gaap:GainLossOnInvestments


Gain
Period End2021-06-302020-12-312020-09-302019-09-30
Value836000.0353000.01738000.0-270000.0
Percentage of GainLossOnInvestments100.0100.0100.0100.0
Percentage of InterestIncomeOperating5971.40.05431.2-53.0

Gains Losses On Extinguishment Of Debt

us-gaap:GainsLossesOnExtinguishmentOfDebt

us-gaap:GainsLossesOnExtinguishmentOfDebt


Gains
Period End2021-06-302015-12-312015-09-302015-06-302013-06-30
Value-12505000.00-878000.0-2173000.0-598000.0
Percentage of GainsLossesOnExtinguishmentOfDebt100.00.0100.0100.0100.0
Percentage of InterestIncomeOperating-89321.40.00.00.00.0

Gross Profit

us-gaap:GrossProfit

us-gaap:GrossProfit


Gross
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value651679063592731565791278162648927717673642781725410730316416812871781.5610727014013
Percentage of GrossProfit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating0.0523171.9120518.78283.30.053729.1160881.45301.60.0100424.2139168.412710.50.098790.7153680.929961.60.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value2.149-46.718-84.659-13.633-39.438-354.512-125.17366-40.21-110.907-82.89780-21.088-96.607-86.49779-40.747-106.266-262.25974-31.173-130.753-86.84191-19.147-138.964-84.65811013-144.552-64.293102-11.864-135.426
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating15350.0-233590.00.0-42603.1-52584.0-46280.90.013095.9-41453.6-10156.30.029082.7-18023.9-19092.30.028429.9-35432.2-43373.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value2.158-49.028-83.145-12.552-38.168-345.973-125.11869-40.613-117.362-86.3983-29.089-105.886-36.44688-48.666-123.861
Percentage of IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating15414.3-245140.00.0-39225.0-50890.7-45166.20.013607.1-41869.1-10747.40.030291.7-24862.4-20926.10.031543.1-42318.3-50555.5

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-0.0092.31-1.514-1.081-1.27-8.539-0.055-2.6020.4036.4553.493-3.3492.1844.704-60.329-10.6186.1214-81.218-15.887-2.7823410-39.638-11.40420-0.9243.2072.1761.7830.358-2.3682.4021.955
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-64.311550.00.0-3378.1-1693.3-1114.80.0-511.2415.5591.10.0-1209.01866.7929.60.0-3778.65321.75874.30.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Income Taxes Paid Net

us-gaap:IncomeTaxesPaidNet

us-gaap:IncomeTaxesPaidNet


Income
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-06-302017-03-31
Value35000.01800000.047000.01000.0202000.064000.0392000.013000.0-115000.0781000.0-8000.0-228000.0603000.023000.0
Percentage of IncomeTaxesPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating0.05625.062.70.10.012.6404.11.20.0281.9-6.8-45.1524.39.4

Interest Expense

us-gaap:InterestExpense

us-gaap:InterestExpense


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.9858.56415161716131111111111111011101010109.4939.4029.3339.735106.165.9544.8914.6624.3954.2974.7185.0415.6785.907
Percentage of InterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating71321.442820.00.050525.023309.32191.00.02278.412333.01060.60.04197.59805.12161.30.03807.59071.34166.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Interest Income Operating

us-gaap:InterestIncomeOperating

us-gaap:InterestIncomeOperating


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value14000.020000.026000.032000.075000.0766000.01459000.0509000.097000.01092000.01650000.0277000.0117000.0506000.0697000.0281000.0115000.0245000.0
Percentage of InterestIncomeOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Interest Paid Net

us-gaap:InterestPaidNet

us-gaap:InterestPaidNet


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.871147.029219.188158.7951011101010109.8429.6699.667
Percentage of InterestPaidNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating6221.473730.027034.666787.512250.72004.3602.82028.911569.1981.2660.23809.48949.61945.11387.23440.2

Litigation Settlement Expense

us-gaap:LitigationSettlementExpense

us-gaap:LitigationSettlementExpense


Litigation
Period End2021-06-30
Value2500000.0
Percentage of LitigationSettlementExpense100.0
Percentage of InterestIncomeOperating17857.1

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value218-51.983-83.145-12.552-38.168-345.973-125.11869-40.613-117.362-55.92186-23.272-101.311-26.16890-46.867-120.658-181.04190-28.391-165.148-97.267131-7.743-159.94-83.73410711-146.335-64.651105-14.266-137.381
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-319788.5-39225.0-50890.7-45166.2-8575.613607.1-41869.1-10747.4-3389.231172.9-19890.6-20021.9-3754.432208.5-40753.9-49248.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value218-51.983-12.552-38.168-345.97369-40.613-117.36286-23.272-101.311
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-39225.0-50890.7-45166.213607.1-41869.1-10747.431172.9-19890.6-20021.9
Percentage of InterestIncomeOperating us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value22-37.3-68.9730.272-22.212-338.176-108.94777-30.253-101.835-74.71191-8.956-86.549-76.46290-31.166-96.103-250.78883-21.152-122.204-76.637102-11.183-130.79-79.73411618-140.152-59.552107-5.639-128.989
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating163100.0-186500.0-265280.8850.0-29616.0-44148.3-7467.215298.8-31188.7-9325.5-4527.933154.5-7654.7-17104.5-10970.232103.2-27100.9-39225.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0258000.01060000.0-331000.0275000.0-257000.0-2077000.0-1327000.0-2253000.0686000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating0.0806.21413.3-43.218.8-50.5-2141.2-121.5-136.5247.7

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax us-gaap:DerivativeInstrumentRisk

us-gaap:InterestRateContract


Other
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value300000.0400000.0300000.0300000.0-300000.0-4700000.01300000.0-2300000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax116.337.7-90.6109.1116.7226.3-98.0102.1
Percentage of InterestIncomeOperating937.5533.339.220.6-58.9-4845.4119.0-139.4
Percentage of InterestIncomeOperating us-gaap:InterestRateContract0.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Foreign Currency Transaction And Translation Adjustment Net Of Tax

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-218000.0-335000.036000.0-86000.0-67000.0-113000.0-33000.0-351000.0105000.0-232000.0-143000.0-97000.0-143000.0227000.038000.069000.062000.0-60000.0-919000.0-91000.0-257000.047000.0-312000.0637000.0-182000.0-1009000.0-247000.0-485000.0500000.0203000.0382000.0501000.0264000.0-743000.0
Percentage of OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-1557.1-1675.0138.5-268.8-89.3-14.8-2.3-69.0108.2-21.2-8.7-35.0-122.244.95.524.653.9-24.50.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1304000.06590000.0172000.0993000.0-444000.0-608000.0-1972000.0-1550000.0576000.01489000.03721000.04984000.0870000.0-380000.01299000.0-4207000.0-331000.0-3108000.0-5921000.0-6695000.0-3779000.0-182000.0-1009000.0-15703000.0-485000.02478000.0212000.08219000.0508000.0268000.0-758000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating9314.332950.0537.51324.0-58.0-119.4-2033.0-141.9207.91272.6735.4715.1309.6-330.4530.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Other
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1304000.06590000.0172000.0993000.0-444000.0-608000.0-1972000.0-1550000.0576000.01489000.03721000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating9314.332950.0537.51324.0-58.0-119.4-2033.0-141.9207.91272.6735.4
Percentage of InterestIncomeOperating us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value218-51.983-83.145-12.552-38.168-345.973-125.11869-40.613-117.362-55.92186-23.272-101.311-26.16890
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-319788.5-39225.0-50890.7-45166.2-8575.613607.1-41869.1-10747.4-3389.231172.9-19890.6-20021.9-3754.432208.5

Revenue From Contract With Customer Excluding Assessed Tax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value308146203386251189241565388194249516375199233516393203241533392205298575379162265551401153298550362166
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating2204800.0730975.0782926.91208093.8334954.724794.416550.7111133.2400923.717823.715093.2186373.6321009.439478.133535.9183703.2341783.583136.70.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems

us-gaap:OperatingSegments


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value308146203386251189241565388194249516357199
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.095.1100.0
Percentage of InterestIncomeOperating2204800.0730975.0782926.91208093.8334954.724794.416550.7111133.2400923.717823.715093.2186373.6305440.239478.1
Percentage of InterestIncomeOperating us-gaap:OperatingSegments0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:ProductOrService

us-gaap:OperatingSegments, hmhc:CoreSolutions


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value16568682061186585273168518124315161
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax53.647.033.553.547.334.435.448.343.226.732.947.140.530.7
Percentage of InterestIncomeOperating1182342.9343355.0262561.5645753.1158421.38528.35853.553686.1173239.24761.44959.587772.6129893.212100.8
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:CoreSolutions0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, hmhc:Extension


Revenue
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value143771249786244181101206169101
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax46.453.032.138.745.443.246.752.340.045.151.0
Percentage of InterestIncomeOperating1022457.1387620.0388390.6129662.711260.848006.3187380.49326.974550.9144701.720117.2
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:Extension0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, hmhc:HMHBooksAndMediaProducts


Revenue
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value553538483940
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.414.020.28.510.121.0
Percentage of InterestIncomeOperating173950.046870.75005.29440.940304.13735.4
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:HMHBooksAndMediaProducts0.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, hmhc:CoreSolutions, hmhc:EducationalServices


Revenue
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value682061186585273168518124315161
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax33.553.547.334.435.448.343.226.732.947.140.530.7
Percentage of InterestIncomeOperating262561.5645753.1158421.38528.35853.553686.1173239.24761.44959.587772.6129893.212100.8
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:CoreSolutions hmhc:EducationalServices0.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, hmhc:Extension, hmhc:EducationalServices


Revenue
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value1249786244181101206169101
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax32.138.745.443.246.752.340.045.151.0
Percentage of InterestIncomeOperating388390.6129662.711260.848006.3187380.49326.974550.9144701.720117.2
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:Extension hmhc:EducationalServices0.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, hmhc:HMHBooksAndMediaProducts, hmhc:HMHBooksAndMedia


Revenue
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value553538483940
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax14.414.020.28.510.121.0
Percentage of InterestIncomeOperating173950.046870.75005.29440.940304.13735.4
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:HMHBooksAndMediaProducts hmhc:HMHBooksAndMedia0.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, hmhc:EducationalServices


Revenue
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value140330216151189517349153188449339163183465350185111487353174247532342128217504364121252504323126
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax69.385.686.079.878.491.589.979.075.887.190.481.678.490.189.291.046.191.490.184.783.192.590.179.282.191.690.779.284.691.789.276.1
Percentage of InterestIncomeOperating542226.91034143.8288084.019789.212980.6101692.3360619.614088.311439.6162323.5290164.132218.026303.4165486.5304875.775666.90.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:EducationalServices0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OperatingSegments, hmhc:HMHBooksAndMedia


Revenue
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6255353852483940
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax30.714.414.020.221.68.510.121.0
Percentage of InterestIncomeOperating240700.0173950.046870.75005.23570.19440.940304.13735.4
Percentage of InterestIncomeOperating us-gaap:OperatingSegments hmhc:HMHBooksAndMedia0.00.00.00.00.00.00.00.0

Selling General And Administrative Expense

us-gaap:SellingGeneralAndAdministrativeExpense

us-gaap:SellingGeneralAndAdministrativeExpense


Selling
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value11489111127106133146188175151158176174150154178166156161185184168175191170143155167152137160156133130
Percentage of SellingGeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating819764.3446175.0427288.5397887.5141772.017409.010034.337123.2180686.613917.99590.563610.8148847.929749.822129.063382.2144491.363817.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1857190020212206216621952513282426162461249526312524245825632719258325682731305229222894313735053312274230113177290126822910
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Assets us-gaap:StatementBusinessSegments

hmhc:EducationalServices


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value15201971199921212206244720032206
Percentage of Assets75.278.480.182.880.878.066.575.8
Percentage of Assets75.278.480.182.880.878.066.575.8
Percentage of Assets hmhc:EducationalServices100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:HMHBooksAndMedia


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-31
Value175186167
Percentage of Assets8.77.46.7
Percentage of Assets8.77.46.7
Percentage of Assets hmhc:HMHBooksAndMedia100.0100.0100.0

us-gaap:CorporateAndOther


Assetsus-gaap:
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value324355328268341487788471
Percentage of Assets16.114.113.210.512.515.526.216.2
Percentage of Assets16.114.113.210.512.515.526.216.2
Percentage of Assets us-gaap:CorporateAndOther100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value158618521930202619771971194621382002180817261806179017051768190618651804185119891960188819381990188811321251132911739761060
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets85.497.595.591.891.389.877.575.776.573.569.268.670.969.469.070.172.270.367.865.267.165.261.856.857.041.341.641.840.436.436.4

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1857190020212206216621952513282426162461249526312524245825632719258325682731305229222894313735053312274230113177290126822910
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-312011-12-31
Value2714890180188223566686613652768825734752795813718763880106296110061198151414241610175918481727170618501943-674.552
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.62.54.58.28.710.222.524.323.526.530.831.429.130.631.029.927.829.732.234.832.934.838.243.243.058.758.458.259.663.663.60.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value-47.83-49.134-55.724-46.551-46.723-47.716-47.272-49.314-48.706-46.734-45.184-40.736-41.312-42.801-46.522-53.295-39.728-26.789-13.291-21.528-23.453
Percentage of StockholdersEquity-17.6-101.5-61.6-25.9-24.7-21.3-8.3-7.2-7.9-7.2-5.9-4.9-5.6-5.7-5.9-6.1-3.3-1.5-0.7-1.13.5
Percentage of Assets-2.6-2.6-2.8-2.1-2.2-2.2-1.9-1.7-1.9-1.9-1.8-1.5-1.6-1.7-1.8-2.0-1.3-0.9-0.50.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value492449214918491549124910490649034898489548934889488548824879486848334784475047412038
Percentage of StockholdersEquity1815.210171.65437.12730.32600.72192.4866.3714.1798.4750.1636.7592.6665.4648.4613.7553.2403.3271.9256.8243.9-302.2
Percentage of Assets265.1259.0243.4222.8226.8223.7195.2173.6187.3198.9196.1185.8193.5198.6190.3178.2154.1158.9163.20.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value1.5221.521.5051.5041.5011.51.4891.4891.4871.4871.4811.4811.481.4791.4791.4751.4561.421.41.40.567
Percentage of StockholdersEquity0.63.11.70.80.80.70.30.20.20.20.20.20.20.20.20.20.10.10.10.1-0.1
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value-4089.185-4307.813-4255.83-4172.685-4160.133-4121.965-3775.992-3650.874-3720.134-3679.608-3562.971-3507.05-3593.399-3570.127-3521.527-3418.34-3133.782-2999.913-2888.422-2777.236-2690.097
Percentage of StockholdersEquity-1507.2-8902.6-4704.5-2317.6-2202.5-1840.5-666.7-531.7-606.3-563.8-463.6-425.0-489.4-474.1-442.9-388.4-261.5-170.5-156.1-142.9398.8
Percentage of Assets-220.1-226.7-210.6-189.1-192.0-187.8-150.2-129.2-142.2-149.5-142.8-133.3-142.3-145.2-137.4-125.1-99.9-99.6-99.20.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-463.013
Percentage of StockholdersEquity-190.9-1070.6-572.6-287.7-274.3-231.3-91.5-75.4-84.4-79.4-67.4-62.8-70.6-68.8-65.1-58.9-38.6
Percentage of Assets-27.9-27.3-25.6-23.5-23.9-23.6-20.6-18.3-19.8-21.0-20.8-19.7-20.5-21.1-20.2-19.0-14.8
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Assets Current

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value58560562075267268271397473755070680756749662177060756370585069466788212341018993122213411029783971
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.531.830.734.131.131.128.434.528.222.428.330.722.520.224.228.323.521.925.827.923.823.128.135.230.736.240.642.235.529.233.4

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value146170281271138254296308157425310430981481337814922615098168234377319562456296139167313231105188329413
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.99.013.912.36.411.611.810.90.63.010.24.01.24.05.84.93.05.88.34.93.45.87.510.89.620.515.29.34.86.310.80.00.00.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-312015-12-31
Value1461702812711382542963081574253104309814813378226234
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.99.013.912.36.411.611.810.90.63.010.24.01.24.05.84.93.08.37.5

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value26692152282273139184434432183203353293164201382304167216438347183256478424196255528568260318
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.44.97.612.812.66.47.315.416.57.48.213.411.66.77.814.111.86.57.914.411.96.38.213.712.87.28.516.619.69.710.9

Inventory Net

us-gaap:InventoryNet

us-gaap:InventoryNet


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value145175166175237265213211267261184170212206154156197209162169218222171185229213183190222208182
Percentage of InventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.89.28.38.011.012.18.57.510.210.67.46.58.48.46.05.87.78.15.95.67.57.75.55.36.97.86.16.07.77.86.3

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:PrepaidExpenseAndOtherAssetsCurrent


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value27251923232219182220152530272921262320253025222929211814161716
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.51.31.01.11.11.00.80.70.90.90.61.01.21.11.20.81.00.90.70.81.00.90.70.80.90.80.60.50.60.60.6

Machinery And Equipment Gross

us-gaap:MachineryAndEquipmentGross

us-gaap:MachineryAndEquipmentGross


Machinery
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1412113123131815
Percentage of MachineryAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.50.51.20.90.40.60.5

Noncurrent Assets

us-gaap:NoncurrentAssets

us-gaap:NoncurrentAssets


Noncurrent
Period End2021-06-302020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2.00.2280.1130.0647.5930.4981.6434.23913
Percentage of NoncurrentAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.00.00.00.30.00.10.10.5

us-gaap:NoncurrentAssets us-gaap:PropertyPlantAndEquipmentByType

us-gaap:LeaseholdImprovements


Noncurrent
Period End2021-06-30
Value0.3
Percentage of NoncurrentAssets15.0
Percentage of Assets0.0
Percentage of Assets us-gaap:LeaseholdImprovements0.0

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:PropertyPlantAndEquipmentGross


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value726671626609563481412351
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets35.926.725.123.820.615.313.712.1

Leasehold Improvements Gross

us-gaap:LeaseholdImprovementsGross

us-gaap:LeaseholdImprovementsGross


Leasehold
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2422222327342827
Percentage of LeaseholdImprovementsGross100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.20.90.90.91.01.11.01.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value633571500455387331273210
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets31.322.720.117.814.210.69.17.2

Amortization Of Intangible Assets

us-gaap:AmortizationOfIntangibleAssets

us-gaap:AmortizationOfIntangibleAssets


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value2.4893.1664.7614.7614.7095.8256.346.3416.2717.6058.2378.2388.148101010101314141417191919231628273317363550
Percentage of AmortizationOfIntangibleAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AmortizationOfIntangibleAssets us-gaap:FiniteLivedIntangibleAssetsByMajorClass

hmhc:DefiniteLivedTrademarksAndTradenamesPublishingRightsAndCustomerRelatedAndOtherIntangibles


Amortization
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value1011111112121214
Percentage of AmortizationOfIntangibleAssets413.8350.6231.0233.6207.7200.3205.7185.4
Percentage of Assets0.00.00.00.00.00.00.00.0
Percentage of Assets hmhc:DefiniteLivedTrademarksAndTradenamesPublishingRightsAndCustomerRelatedAndOtherIntangibles0.00.00.00.00.00.00.00.0

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value82869395100101100104108116125143149150153153157169175179175160149134133133138137140135140
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.44.54.64.34.74.64.03.74.14.75.05.45.96.16.05.66.16.66.45.96.05.54.83.84.04.94.64.34.85.14.8

Long Term Investments

us-gaap:LongTermInvestments

us-gaap:LongTermInvestments


Long
Period End2021-06-302021-03-312020-12-312020-09-302019-12-31
Value5200000.04400000.04400000.02300000.04000000.0
Percentage of LongTermInvestments100.0100.0100.0100.0100.0
Percentage of Assets0.30.20.20.10.2

Goodwill

us-gaap:Goodwill

us-gaap:Goodwill


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-10-282013-04-102012-12-31
Value4374374374544544547167167167167167137837837837837837837837837837837837837835325325325325315317.64.1520
Percentage of Goodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets23.623.021.720.621.020.728.525.427.429.128.727.131.031.930.528.830.330.528.725.726.827.125.022.423.719.417.716.818.419.818.30.00.00.0

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value381391428440451462474486520
Percentage of IntangibleAssetsNetExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets20.520.621.219.920.821.018.917.220.9

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsNet

hmhc:PublishingRights


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value13162025303440466775839110111212313414816217719120911801180118011801180118011801180
Percentage of FiniteLivedIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.70.91.01.11.41.61.61.72.72.93.33.74.04.14.85.25.45.36.16.66.733.735.643.039.237.140.744.040.5
Percentage of Assets hmhc:PublishingRights0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CustomerRelatedIntangibleAssets


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value129132136139142144147150156160164168172174177183189194200205210442442283283283283283283
Percentage of FiniteLivedIntangibleAssetsNet931.6807.9665.5551.8473.2416.7363.5320.9233.5213.2197.0183.8169.7155.1143.6136.2127.9119.7112.9107.1100.637.537.524.024.024.024.024.024.0
Percentage of Assets7.07.06.86.36.66.65.95.36.36.16.56.96.76.46.97.16.96.46.87.16.712.613.410.39.48.99.810.69.7
Percentage of Assets us-gaap:CustomerRelatedIntangibleAssets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value136147156172189
Percentage of FiniteLivedIntangibleAssetsNet665.5363.5233.5169.7127.9
Percentage of Assets6.85.96.36.76.9
Percentage of Assets us-gaap:OtherIntangibleAssets0.00.00.00.00.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302014-12-31
Value768111011411712112512713013313613816817117517818218418751515253494494439
Percentage of FiniteLivedIntangibleAssetsNet550.6497.3538.6452.3392.6349.8308.5272.60.00.0202.7184.1202.0187.4171.9157.9147.5137.3126.431.429.227.425.441.941.937.3
Percentage of Assets4.14.35.55.25.45.55.04.55.05.45.55.36.77.06.86.57.17.26.91.71.81.81.714.114.914.6
Percentage of Assets us-gaap:TrademarksAndTradeNames0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType

us-gaap:OtherIntangibleAssets, us-gaap:SubsequentEvent


Finite
Period End2021-07-08
Value1.3
Percentage of FiniteLivedIntangibleAssetsNet0.0
Percentage of Assets0.0
Percentage of Assets us-gaap:OtherIntangibleAssets us-gaap:SubsequentEvent0.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value119123126129132135132135138144
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets6.46.56.35.96.16.25.34.85.35.9

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value35293434382931312827282828231918211919202422383732232836262629
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.91.61.71.61.81.41.31.11.11.11.11.11.11.00.80.70.80.80.70.70.80.81.21.11.00.90.91.10.91.01.0

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value4547497165735288108115768794120619591997686124101948078765110010967105
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.52.52.43.23.03.32.13.14.14.73.13.33.84.92.43.53.63.92.82.84.23.53.02.32.42.81.73.13.82.53.6

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value522507551612593620555596583456487547539455504557512464505536507453506530443352450458397282353
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.126.727.327.827.428.222.121.122.318.619.520.821.418.519.720.519.818.118.517.617.415.716.115.113.412.915.014.413.710.512.1

Long Term Debt Current

us-gaap:LongTermDebtCurrent

us-gaap:LongTermDebtCurrent


Long
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1919191919198.08.08.08.08.08.08.08.08.08.08.08.08.08.08.08.08.08.02.5672.52.52.52.5
Percentage of LongTermDebtCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets1.00.90.90.90.90.80.30.30.30.30.30.30.30.30.30.30.30.30.30.30.30.30.20.20.12.20.10.10.10.1

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value109.9489.6699.3399.2319.1718.685111214
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.60.50.50.40.40.40.30.40.50.6

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value52232426272724342522262830232231382523313838343739372737342832
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.81.21.21.21.31.21.01.21.00.91.11.11.21.00.91.21.51.00.91.01.31.31.11.11.21.40.91.21.21.11.1

Long Term Debt

us-gaap:LongTermDebt

us-gaap:LongTermDebt


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-312017-12-312016-12-312015-12-312015-09-302015-06-302015-03-312014-12-312014-03-312013-12-31
Value316640643647650653657772780788792794796178243245245
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets17.033.731.829.330.029.826.130.930.428.825.322.724.06.58.19.18.4

us-gaap:LongTermDebt us-gaap:DebtInstrument

hmhc:TermLoan


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value20342346349353357361760761762768764765767768769770771772773775776792794796178243243244245245
Percentage of LongTermDebt6.653.553.854.154.454.755.00.00.00.099.50.00.00.098.50.00.00.098.10.00.00.0100.0100.0100.0100.0100.00.00.0100.0100.0
Percentage of Assets1.118.017.115.916.316.314.426.929.131.030.829.130.331.230.028.329.830.028.325.426.526.825.322.724.06.58.17.78.49.18.4
Percentage of Assets hmhc:TermLoan0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentRedemptionPeriodOne, hmhc:TermLoan


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312015-06-302014-12-31
Value203423463493533573610.0243
Percentage of LongTermDebt6.653.553.854.154.454.755.00.0100.0
Percentage of Assets1.118.017.115.916.316.314.40.08.1
Percentage of Assets us-gaap:DebtInstrumentRedemptionPeriodOne hmhc:TermLoan0.00.00.00.00.00.00.00.00.0

us-gaap:DebtInstrumentRedemptionPeriodTwo, us-gaap:SeniorNotes


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value295298297297296296295
Percentage of LongTermDebt93.446.546.245.945.645.345.0
Percentage of Assets15.915.714.713.513.713.511.8
Percentage of Assets us-gaap:DebtInstrumentRedemptionPeriodTwo us-gaap:SeniorNotes0.00.00.00.00.00.00.0

us-gaap:LongTermDebt us-gaap:LongtermDebtType

us-gaap:SecuredDebt


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value295298297297296296295
Percentage of LongTermDebt93.446.546.245.945.645.345.0
Percentage of Assets15.915.714.713.513.713.511.8
Percentage of Assets us-gaap:SecuredDebt0.00.00.00.00.00.00.0

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value316621624628631634638752753754755756757759760761762763764765767768784786788176175241241242243
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets17.032.730.928.529.128.925.426.628.830.730.328.830.030.929.728.029.529.728.025.126.226.525.022.423.86.45.87.68.39.08.4

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

us-gaap:DeferredIncomeTaxLiabilitiesNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value181816182030
Percentage of DeferredIncomeTaxLiabilitiesNet100.0100.0100.0100.0100.0100.0
Percentage of Assets1.01.00.80.90.91.2

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1615142022232623
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.60.60.80.80.80.90.8

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.1050.1522.4193.5023.4935.0496.0286.7466.585.781722211918192022222727251922939597102105106107
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.10.20.20.20.20.20.30.20.70.90.80.80.70.70.80.90.80.91.00.90.60.62.83.53.23.23.64.03.7

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value134129132133135137134137140142
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets7.26.86.56.06.36.35.44.95.45.8

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value2527272626
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0100.0
Percentage of Assets1.31.01.01.11.1

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value2725252526
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree100.0100.0100.0100.0100.0
Percentage of Assets1.40.91.01.01.0

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value2923232324
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0100.0
Percentage of Assets1.40.80.90.91.0

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value2825252527
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive100.0100.0100.0100.0100.0
Percentage of Assets1.40.91.01.01.1

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value110161161161171
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive100.0100.0100.0100.0100.0
Percentage of Assets5.55.76.26.66.9

Operating Lease Liability

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


Operating
Period End2020-12-312019-12-312019-09-302019-06-302019-03-31
Value141143148152156
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0
Percentage of Assets7.05.75.35.86.4

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


Lessee
Period End2020-12-312019-09-302019-06-302019-03-312018-12-31
Value245270279287308
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0100.0100.0100.0100.0
Percentage of Assets12.29.610.711.712.4

Lessee Operating Lease Liability Undiscounted Excess Amount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount

us-gaap:LesseeOperatingLeaseLiabilityUndiscountedExcessAmount


Lessee
Period End2020-12-31
Value104
Percentage of LesseeOperatingLeaseLiabilityUndiscountedExcessAmount100.0
Percentage of Assets5.2

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-312011-12-31
Value2714890180188223566686613652768825734752795813718763880106296110061198151414241610175918481727170618501943-674.552
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.62.54.58.28.710.222.524.323.526.530.831.429.130.631.029.927.829.732.234.832.934.838.243.243.058.758.458.259.663.663.60.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value-47.83-49.134-55.724-46.551-46.723-47.716-47.272-49.314-48.706-46.734-45.184-40.736-41.312-42.801-46.522-53.295-39.728-26.789-13.291-21.528-23.453
Percentage of StockholdersEquity-17.6-101.5-61.6-25.9-24.7-21.3-8.3-7.2-7.9-7.2-5.9-4.9-5.6-5.7-5.9-6.1-3.3-1.5-0.7-1.13.5
Percentage of Assets-2.6-2.6-2.8-2.1-2.2-2.2-1.9-1.7-1.9-1.9-1.8-1.5-1.6-1.7-1.8-2.0-1.3-0.9-0.50.00.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value492449214918491549124910490649034898489548934889488548824879486848334784475047412038
Percentage of StockholdersEquity1815.210171.65437.12730.32600.72192.4866.3714.1798.4750.1636.7592.6665.4648.4613.7553.2403.3271.9256.8243.9-302.2
Percentage of Assets265.1259.0243.4222.8226.8223.7195.2173.6187.3198.9196.1185.8193.5198.6190.3178.2154.1158.9163.20.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value1.5221.521.5051.5041.5011.51.4891.4891.4871.4871.4811.4811.481.4791.4791.4751.4561.421.41.40.567
Percentage of StockholdersEquity0.63.11.70.80.80.70.30.20.20.20.20.20.20.20.20.20.10.10.10.1-0.1
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value-4089.185-4307.813-4255.83-4172.685-4160.133-4121.965-3775.992-3650.874-3720.134-3679.608-3562.971-3507.05-3593.399-3570.127-3521.527-3418.34-3133.782-2999.913-2888.422-2777.236-2690.097
Percentage of StockholdersEquity-1507.2-8902.6-4704.5-2317.6-2202.5-1840.5-666.7-531.7-606.3-563.8-463.6-425.0-489.4-474.1-442.9-388.4-261.5-170.5-156.1-142.9398.8
Percentage of Assets-220.1-226.7-210.6-189.1-192.0-187.8-150.2-129.2-142.2-149.5-142.8-133.3-142.3-145.2-137.4-125.1-99.9-99.6-99.20.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312015-12-31
Value-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-518.03-463.013
Percentage of StockholdersEquity-190.9-1070.6-572.6-287.7-274.3-231.3-91.5-75.4-84.4-79.4-67.4-62.8-70.6-68.8-65.1-58.9-38.6
Percentage of Assets-27.9-27.3-25.6-23.5-23.9-23.6-20.6-18.3-19.8-21.0-20.8-19.7-20.5-21.1-20.2-19.0-14.8
Percentage of Assets us-gaap:TreasuryStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1522000.01520000.01505000.01504000.01501000.01500000.01489000.01489000.01487000.01487000.01481000.01481000.01480000.01479000.01479000.01479000.01478000.01477000.01475000.01474000.01466000.01462000.01456000.01348000.01359000.01432000.01420000.01400000.01400000.01400000.01400000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.10.00.10.10.00.00.00.10.00.00.00.10.0

Additional Paid In Capital Common Stock

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AdditionalPaidInCapitalCommonStock


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value492449214918491549124910490649034898489548934889488548824879487748734870486848654850484348334822480947964784
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets265.1259.0243.4222.8226.8223.7195.2173.6187.3198.9196.1185.8193.5198.6190.3179.3188.6189.7178.2159.4166.0167.3154.1137.6145.2174.9158.9

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value-4089.185-4307.813-4255.83-4172.685-4160.133-4121.965-3775.992-3650.874-3720.134-3679.608-3562.971-3507.05-3593.399-3570.127-3521.527-3495.359-3585.865-3538.998-3418.34-3237.299-3327.321-3298.93-3133.782-3036.515-3167.596-3159.853-2999.913-2916.179-3023.209-3034.757-2888.422
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-220.1-226.7-210.6-189.1-192.0-187.8-150.2-129.2-142.2-149.5-142.8-133.3-142.3-145.2-137.4-128.5-138.8-137.8-125.1-106.1-113.9-114.0-99.9-86.6-95.6-115.2-99.6-91.8-104.2-113.1-99.2

us-gaap:RetainedEarningsAccumulatedDeficit us-gaap:CumulativeEffectPeriodOfAdoption, us-gaap:AdjustmentsForNewAccountingPronouncements

srt:CumulativeEffectPeriodOfAdoptionAdjustment, us-gaap:AccountingStandardsUpdate201602


Retained
Period End2020-12-31
Value0.8
Percentage of RetainedEarningsAccumulatedDeficit-0.0
Percentage of Assets0.0
Percentage of Assets srt:CumulativeEffectPeriodOfAdoptionAdjustment us-gaap:AccountingStandardsUpdate2016020.0

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


Accumulated
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-31
Value-47830000.0-49134000.0-55724000.0-46551000.0-46723000.0-47716000.0-47272000.0-49314000.0-48706000.0-46734000.0-45184000.0-40736000.0-41312000.0-42801000.0-46522000.0-51506000.0-52376000.0-51996000.0-53295000.0-49088000.0-48757000.0-45649000.0-39728000.0-33033000.0-27980000.0-27798000.0-26789000.0-11086000.0-10601000.0-13079000.0-13291000.0-21528000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-2.6-2.6-2.8-2.1-2.2-2.2-1.9-1.7-1.9-1.9-1.8-1.5-1.6-1.7-1.8-1.9-2.0-2.0-2.0-1.6-1.7-1.6-1.3-0.9-0.8-1.0-0.9-0.3-0.4-0.5-0.50.0

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value5185185185185185185185185185185185185185185185185185185185185144944632391910.00.00.0
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0
Percentage of Assets27.927.325.623.523.923.620.618.319.821.020.819.720.521.120.219.020.020.219.017.017.617.114.86.85.80.00.00.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue


Adjustments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2.9722.6822.9692.1013.3863.7353.6043.4423.23.0822.873
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value2.9722.6822.9692.1013.3863.7353.6043.4423.23.0822.873
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-9.797-81.25640264-32.509-156.767127393-89.862-176.06371207-67.128-96.68696178190432-29.563-102.544110199-54.406-98.362
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-69978.6-406280.0154161.5826381.2-43345.3-20465.78745.977268.6-92641.2-16123.04330.274830.7-57374.4-19107.913899.463506.40.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value324-24.703-25.675-27.388-28.582-30.626-31.241-35.683-27.676-1.7275-82.248-48.80748-79.88-121.905-38.06-285.738-1.491-42.33-26.758-71.962-28.661-41.197
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating2317550.0-123515.0-98750.0-85587.5-38109.3-3998.2-2141.3-7010.4-28532.0-157.54599.2-29692.4-41715.49637.0-11460.5-43382.60.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-339.02-4.34-4.75-104.335-54.75145-108.685-64.05258-1.3971.726-51.43847-2.392-2.0-1.3037.484102.72-0.991-2.2-0.625-0.625-0.625
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-2421571.4-21700.0-18269.2-326046.9-73000.019021.5-7449.3-12583.960275.3-127.9104.6-18569.741008.5-472.7-286.9-463.70.00.00.00.00.00.00.00.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-24.36-110.2999.657132-115.841-41.688-12.323293-59.071-179.1814973-67.955-50.3151455
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-174000.0-551495.037142.3414746.9-154454.7-5442.3-844.657674.3-60897.9-16408.49034.026568.6-58081.2-9943.72151.919660.1

Increase Decrease In Accounts Receivable

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInAccountsReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1593.647-129.3479.011133-44.444-250.4782.821248-20.482-149.50167129-36.645-181.64678137-48.812-222.5991163-72.709-222.63454196-58.866-272.731-39.971305-57.854-158.127121173-49.125
Percentage of IncreaseDecreaseInAccountsReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-30.76330-8.857-61.406-28.138521.315-56.0265.8467714-38.4755.99251-1.923-41.336-11.20246-7.247-49.262-3.14250-14.154-44.1242.56629-6.465-31.6471326-16.262-47.4119.66538
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-9.797-81.25640264-32.509-156.767127393-89.862-176.06371207-67.128-96.68696178190432-29.563-102.544110199-54.406-98.362
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-69978.6-406280.0154161.5826381.2-43345.3-20465.78745.977268.6-92641.2-16123.04330.274830.7-57374.4-19107.913899.463506.40.00.00.00.00.00.00.00.0

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value218-51.983-83.145-12.552-38.168-345.973-125.11869-40.613-117.362-55.92186-23.272-101.311-26.16890-46.867-120.658-181.04190-28.391-165.148-97.267131-7.743-159.94-83.73410711-146.335-64.651105-14.266-137.381
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-319788.5-39225.0-50890.7-45166.2-8575.613607.1-41869.1-10747.4-3389.231172.9-19890.6-20021.9-3754.432208.5-40753.9-49248.20.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-31
Value218-51.983-12.552-38.168-345.97369-40.613-117.36286-23.272-101.311
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-39225.0-50890.7-45166.213607.1-41869.1-10747.431172.9-19890.6-20021.9
Percentage of InterestIncomeOperating us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.0

Profit Loss

us-gaap:ProfitLoss

us-gaap:ProfitLoss


Profit
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value218-51.983-83.145-12.552-38.168-345.973-125.11869-40.613-117.362-55.92186-23.272-101.311-26.16890
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating1561628.6-259915.0-319788.5-39225.0-50890.7-45166.2-8575.613607.1-41869.1-10747.4-3389.231172.9-19890.6-20021.9-3754.432208.5

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value2.9432.6072.8223.1122.1633.4762.8743.8353.7083.5513.8853.3023.1992.9232.8072.5462.9312.5441.8132.0813.673.0032.5243.1163.7173.0952.5712.8613.5472.3972.6013.6481.6891.586
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value324-24.703-25.675-27.388-28.582-30.626-31.241-35.683-27.676-1.7275-82.248-48.80748-79.88-121.905-38.06-285.738-1.491-42.33-26.758-71.962-28.661-41.197
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating2317550.0-123515.0-98750.0-85587.5-38109.3-3998.2-2141.3-7010.4-28532.0-157.54599.2-29692.4-41715.49637.0-11460.5-43382.60.00.00.00.00.00.00.00.0

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.1099.94915101211108.9927.983101216121217149.3641715343124331817141718161413151515
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-339.02-4.34-4.75-104.335-54.75145-108.685-64.05258-1.3971.726-51.43847-2.392-2.0-1.3037.484102.72-0.991-2.2-0.625-0.625-0.625
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of InterestIncomeOperating-2421571.4-21700.0-18269.2-326046.9-73000.019021.5-7449.3-12583.960275.3-127.9104.6-18569.741008.5-472.7-286.9-463.70.00.00.00.00.00.00.00.0

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt

us-gaap:RepaymentsOfLongTermDebt


Repayments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3374.754.754.754.754.757662.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.02.0178640.6250.6250.6250.6250.6250.6250.6250.625
Percentage of RepaymentsOfLongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

us-gaap:EffectiveIncomeTaxRateContinuingOperations


Effective
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-0.4-4.9-0.27.90.032-0.0210.03-0.039-0.01-0.0580.001-0.042-0.104-0.049-0.181-0.133-0.15-0.135-0.008-0.2140.089-0.2630.323-0.4330.5960.151-0.2890.0290.1590.012-0.023-0.0230.2020.014
Percentage of EffectiveIncomeTaxRateContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value12.9513.112.9813.4514.1313.6213.3312.7412.5
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Liabilities

us-gaap:DeferredTaxLiabilities

us-gaap:DeferredTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value132823186713688
Percentage of DeferredTaxLiabilities100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

us-gaap:DeferredTaxAssetsNet


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value146176124133160100178217
Percentage of DeferredTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0

Unrecognized Tax Benefits

us-gaap:UnrecognizedTaxBenefits

us-gaap:UnrecognizedTaxBenefits


Unrecognized
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312012-12-312011-12-31
Value15151515151515161515151616636378636262627470
Percentage of UnrecognizedTaxBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value662583562571759668550527
Percentage of DeferredTaxAssetsValuationAllowance100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan

hmhc:AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan


Adjustments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value12000.0636000.0570000.0-1000.0679000.0735000.01000.0702000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Adjustments
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value12000.0634000.0567000.0-1000.0678000.0734000.01000.0701000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan100.099.799.5100.099.999.9100.099.9

us-gaap:CommonStock


Adjustments
Period End2021-03-312020-09-302020-03-312019-09-302019-03-31
Value2000.03000.01000.01000.01000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalStockIssuedDuringPeriodValueEmployeeStockPurchasePlan0.30.50.10.10.1

hmhc:AmortizationAndImpairmentsOfOperatingLeaseAssets

hmhc:AmortizationAndImpairmentsOfOperatingLeaseAssets


Amortization
Period End2020-09-302019-09-30
Value2.9113.457
Percentage of AmortizationAndImpairmentsOfOperatingLeaseAssets100.0100.0

hmhc:AmortizationOfFilmAsset

hmhc:AmortizationOfFilmAsset


Amortization
Period End2020-12-312020-09-302020-06-302019-12-312019-09-302019-06-30
Value9.0994.6980.1563.0630.01.76
Percentage of AmortizationOfFilmAsset100.0100.0100.0100.00.0100.0

hmhc:AmortizationOfOtherIntangibleAssets

hmhc:AmortizationOfOtherIntangibleAssets


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value7.8697.9066.7666.2746.2726.2735.7916.3836.6126.5246.6956.6967.0517.2417.2967.2488.1288.0768.6265.985.9686.1767.3047.2554.2613.2183.1893.0293.0072.9452.8812.6542.68110
Percentage of AmortizationOfOtherIntangibleAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:AmortizationOfPrePublicationCosts

hmhc:AmortizationOfPrePublicationCosts


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value26253231313041393533292827263433292736333128333227263533322833313026
Percentage of AmortizationOfPrePublicationCosts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:ContractWithCustomerAssetsNetPercentChange

hmhc:ContractWithCustomerAssetsNetPercentChange


Contract
Period End2021-06-302021-03-312020-12-31
Value20.52.8507.31
Percentage of ContractWithCustomerAssetsNetPercentChange100.0100.0100.0

hmhc:ContractWithCustomerLiabilitiesNetPercentChange

hmhc:ContractWithCustomerLiabilitiesNetPercentChange


Contract
Period End2021-06-302021-03-312020-12-31
Value2.0-4.7-5.66
Percentage of ContractWithCustomerLiabilitiesNetPercentChange100.0100.0100.0

hmhc:DebtEquityOfferingCost

hmhc:DebtEquityOfferingCost


Debt
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value0.7140.3390.00.0275.5960.1830.2610.2870.6270.151.9240.1821.1870.0-0.2880.5160.0520.0920.8120.1676.771-0.10115
Percentage of DebtEquityOfferingCost100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:DebtInstrumentPercentageOfPrincipalForSubjectToPrepaymentPremium us-gaap:LongtermDebtType

hmhc:DebtInstrumentPercentageOfPrincipalForSubjectToPrepaymentPremium

hmhc:TermLoan


Debt
Period End2020-12-31
Value0
Percentage of DebtInstrumentPercentageOfPrincipalForSubjectToPrepaymentPremium0.0

hmhc:DebtInstrumentRepaid us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

hmhc:DebtInstrumentRepaid

us-gaap:DebtInstrumentRedemptionPeriodOne, hmhc:TermLoan


Debt
Period End2021-06-30
Value334
Percentage of DebtInstrumentRepaid100.0

hmhc:DebtInstrumentsFixedChargeCoverageRatio us-gaap:Range, us-gaap:CreditFacility

hmhc:DebtInstrumentsFixedChargeCoverageRatio

srt:Minimum, us-gaap:RevolvingCreditFacility


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302015-07-222015-06-22
Value01.00001.00001.0001.01.0
Percentage of DebtInstrumentsFixedChargeCoverageRatio0.0100.00.00.00.0100.00.00.00.0100.00.00.0100.0100.0

hmhc:IncomeFromTransitionServicesAgreement

hmhc:IncomeFromTransitionServicesAgreement


Income
Period End2021-06-302019-12-312019-09-302019-06-30
Value854000.00571000.01851000.0
Percentage of IncomeFromTransitionServicesAgreement100.00.0100.0100.0

hmhc:IncreaseDecreaseInContractAssetsAndLiabilities

hmhc:IncreaseDecreaseInContractAssetsAndLiabilities


Increase
Period End2021-06-302021-03-312020-09-30
Value17-42.2119
Percentage of IncreaseDecreaseInContractAssetsAndLiabilities100.0100.0100.0

hmhc:IncreaseDecreaseInOperatingLeaseLiabilities

hmhc:IncreaseDecreaseInOperatingLeaseLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value5596000.0-2466000.05602000.0-2098000.0-2196000.0-3304000.0-4831000.0-4031000.0-4225000.0-4194000.0
Percentage of IncreaseDecreaseInOperatingLeaseLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:PaymentsForAdditionsToPrepublicationCost

hmhc:PaymentsForAdditionsToPrepublicationCost


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value15141016161821252925313036255031292729293232243327182528233814374231
Percentage of PaymentsForAdditionsToPrepublicationCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:SegmentAdjustedEbitda

hmhc:SegmentAdjustedEbitda


Segment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value569735-17.387-3.75714847-26.5062.30415961-15.3324.80716572-24.092-19.15816875-41.1951519179-51.8219.052200109-53.1955420597-32.441
Percentage of SegmentAdjustedEbitda100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:SegmentAdjustedEbitda us-gaap:ConsolidationItems

us-gaap:CorporateNonSegment


Segment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-9.376-10.665-8.766-11.842-14.406-13.002-8.959-9.71-7.466-10.612-10.898-11.442-12.005-13.654-12.131-12.869-12.532-12.339-10.186-13.449-11.031-10.537-7.208-13.334-8.916-13.192-12.017-11.65-16.827-5.738-7.559-12.488
Percentage of SegmentAdjustedEbitda-16.5-11.0-24.468.1383.4-8.7-18.936.6-324.0-6.6-17.674.6-249.7-8.3-16.653.465.4-7.3-13.532.6-70.7-5.5-9.025.7-98.5-6.6-11.021.9-30.7-2.8-7.838.5

hmhc:SegmentAdjustedEbitda us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, hmhc:EducationalServices


Segment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value8.6749744-4.8658.00115356-20.9652.55315472-3.0539.62917282-10.801-9.76617485-24.0592119886-37.34713206119-40.22767202100-26.613
Percentage of SegmentAdjustedEbitda15.3100.4123.728.0-213.0103.2119.479.1110.896.9117.519.9200.3104.3112.944.851.0103.5113.158.4141.0103.5108.572.1145.1103.0109.275.6122.498.6103.082.0

us-gaap:OperatingSegments, hmhc:HMHBooksAndMedia


Segment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value16100.254-0.682.6488.302-0.2114.169
Percentage of SegmentAdjustedEbitda29.610.60.73.9-70.55.6-0.4-15.7

us-gaap:AdjustmentForAmortization

us-gaap:AdjustmentForAmortization


Adjustment
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value4342424253524847444342445351484959545152605951526361596269676676
Percentage of AdjustmentForAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease

us-gaap:AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease


Allowance
Period End2020-12-31
Value200000.0
Percentage of AllowanceForDoubtfulAccountsReceivablePeriodIncreaseDecrease100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs

us-gaap:AllowanceForDoubtfulAccountsReceivableWriteOffs


Allowance
Period End2021-06-302021-03-312020-12-31
Value200000.0100000.0100000.0
Percentage of AllowanceForDoubtfulAccountsReceivableWriteOffs100.0100.0100.0

us-gaap:AmortizationOfDeferredSalesCommissions

us-gaap:AmortizationOfDeferredSalesCommissions


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value4.10.81.96.13.81.12.27.42.31.32.73.53.21.1
Percentage of AmortizationOfDeferredSalesCommissions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfFinancingCostsAndDiscounts

us-gaap:AmortizationOfFinancingCostsAndDiscounts


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value0.8280.661.51.5141.5021.4881.151.0461.0441.0461.0451.0451.0451.0461.0451.0461.0441.0461.0471.0441.0441.0461.4091.4381.163.209
Percentage of AmortizationOfFinancingCostsAndDiscounts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetImpairmentCharges

us-gaap:AssetImpairmentCharges


Asset
Period End2020-12-312020-09-302020-06-302020-03-312014-12-312014-09-302014-06-302013-12-312013-09-302013-06-30
Value170.00.02620.40.01.2790.50.08.5
Percentage of AssetImpairmentCharges100.00.00.0100.0100.00.0100.0100.00.0100.0

us-gaap:AssetImpairmentCharges us-gaap:FairValueByAssetClass

us-gaap:Goodwill


Asset
Period End2020-12-312020-09-302020-06-302020-03-31
Value170.00.0262
Percentage of AssetImpairmentCharges100.00.00.0100.0

us-gaap:CapitalizedContractCostAmortization

us-gaap:CapitalizedContractCostAmortization


Capitalized
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value1400000.01300000.01200000.01200000.0700000.0700000.02300000.0700000.0
Percentage of CapitalizedContractCostAmortization100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations


Cash
Period End2021-06-302021-03-312020-06-302020-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-247000.0-400000.0-92000.0-262000.0-899000.0-1674000.0-2283000.0-1976000.0-2461000.0
Percentage of CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations

us-gaap:CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations


Cash
Period End2021-06-302021-03-312020-06-302020-03-312018-12-312017-12-31
Value-15.4119-13.4115-6.5312
Percentage of CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice

us-gaap:ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice


Contract
Period End2021-06-302021-03-312020-12-31
Value119000.016000.0553000.0
Percentage of ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimateOfTransactionPrice100.0100.0100.0

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized

us-gaap:ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized


Contract
Period End2021-06-302021-03-312020-12-31
Value17-42.231-48.169
Percentage of ContractWithCustomerLiabilityChangeInTimeframePerformanceObligationSatisfiedRevenueRecognized100.0100.0100.0

us-gaap:ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueModificationOfContract

us-gaap:ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueModificationOfContract


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value10174408193793570754833687447
Percentage of ContractWithCustomerLiabilityCumulativeCatchUpAdjustmentToRevenueModificationOfContract100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1 us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentBasisSpreadOnVariableRate1

us-gaap:DebtInstrumentRedemptionPeriodOne, hmhc:TermLoan


Debt
Period End2021-03-312020-03-31
Value7.250.0725
Percentage of DebtInstrumentBasisSpreadOnVariableRate1100.0100.0

us-gaap:DeferredIncomeTaxesAndTaxCredits

us-gaap:DeferredIncomeTaxesAndTaxCredits


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-0.2112.085-2.271-1.589-1.367-9.1281.955-3.161-0.1565.8972.543-3.2781.6454.23-58.11-10.1655.3513-81.635-15.964-4.046336.02135-8.19714
Percentage of DeferredIncomeTaxesAndTaxCredits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1000.02000.02000.02000.041000.040000.041000.041000.0-3000.0-3000.0-4000.0-3000.0-21000.0-22000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value-597000.0-850000.0-582000.0-581000.0-581000.0-581000.0-276000.0-251000.0-251000.0-251000.0-355000.0-354000.0-354000.0-354000.0-201000.0-201000.0-201000.0-201000.0-13000.0-12000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses0.00.0-58200.0-29050.0-29050.0-29050.0-673.2-627.5-612.2-612.20.00.00.00.06700.06700.05025.06700.061.954.5

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAmortizationOfPriorServiceCostCredit

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value11000.011000.09000.011000.011000.011000.010000.010000.010000.010000.0-173000.0-172000.0-172000.0-172000.0-335000.0-335000.0-335000.0-335000.0-335000.0-335000.0
Percentage of DefinedBenefitPlanAmortizationOfPriorServiceCostCredit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value1.841.9161.8541.8551.8551.8551.9041.9181.9181.9181.9981.9941.9951.9952.3162.3162.3162.3162.2872.288
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanInterestCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanInterestCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value68000.068000.0105000.0107000.0107000.0107000.0146000.0145000.0145000.0145000.0168000.0168000.0168000.0168000.0193000.0193000.0192000.0193000.0219000.0219000.0
Percentage of DefinedBenefitPlanInterestCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value810000.0687000.01097000.01097000.01097000.01097000.01512000.01511000.01511000.01511000.01325000.01325000.01325000.01325000.01382000.01382000.01382000.01382000.01306000.01306000.0
Percentage of DefinedBenefitPlanInterestCost1191.21010.31044.81025.21025.21025.21035.61042.11042.11042.1788.7788.7788.7788.7716.1716.1719.8716.1596.3596.3

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value98000.098000.0129000.0133000.0133000.0133000.0129000.0130000.0129000.0129000.027000.028000.028000.028000.0-105000.0-106000.0-105000.0-106000.0-54000.0-53000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-30
Value-53000.0121000.0-177000.0-177000.0-177000.0-156000.0-156000.0-156000.0-315000.0-316000.0-316000.0-733000.0-733000.0-733000.0-970000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost-54.1123.5-133.1-133.1-133.1-120.0-120.9-120.9-1125.0-1128.6-1128.6691.5698.1691.51830.2

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1


Defined
Period End2021-06-302021-03-31
Value-400000.0-500000.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1100.0100.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1 us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2021-06-302021-03-31
Value-380000.0-500000.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlements195.0100.0

us-gaap:DefinedBenefitPlanServiceCost us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanServiceCost

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value19000.019000.016000.017000.017000.017000.014000.015000.015000.015000.032000.033000.032000.032000.034000.033000.034000.033000.041000.041000.0
Percentage of DefinedBenefitPlanServiceCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:Depreciation

us-gaap:Depreciation


Depreciation
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value1212121214131616181721191818191920211918191717181917181717141514
Percentage of Depreciation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DepreciationAndAmortization

us-gaap:DepreciationAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value48476559555571656768675663637170676880757170807669718279777987828290
Percentage of DepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet us-gaap:Range, us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet

srt:Maximum, us-gaap:InterestRateContract


Derivative
Period End2020-12-312020-03-31
Value0100000.0
Percentage of DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet0.0100.0

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax

us-gaap:DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax


Discontinued
Period End2021-06-30
Value214
Percentage of DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax

hmhc:HMHBooksAndMediaSegment


Discontinued
Period End2021-06-302021-03-312020-06-302020-03-31
Value1.946-2.861-5.631-7.706
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax


Discontinued
Period End2021-06-302021-03-312020-06-302020-03-31
Value1.95-2.955-5.731-7.947
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax100.0100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare


Discontinued
Period End2021-06-302020-06-302018-06-30
Value1.7-0.050.05
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerBasicShare100.0100.0100.0

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare

us-gaap:DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare


Discontinued
Period End2021-06-302020-06-302018-06-30
Value1.66-0.050.05
Percentage of DiscontinuedOperationIncomeLossFromDiscontinuedOperationNetOfTaxPerDilutedShare100.0100.0100.0

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DiscontinuedOperationTaxEffectOfDiscontinuedOperation

hmhc:HMHBooksAndMediaSegment


Discontinued
Period End2021-06-302021-03-312020-06-302020-03-31
Value-4000.094000.0100000.0241000.0
Percentage of DiscontinuedOperationTaxEffectOfDiscontinuedOperation100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-06-302021-03-312020-06-302020-03-31
Value15373136
Percentage of DisposalGroupIncludingDiscontinuedOperationCostsOfGoodsSold100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-06-302021-03-312020-06-302020-03-31
Value01395000.01795000.01885000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization0.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationInterestExpense

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-06-302021-03-312020-06-302020-03-31
Value2.8056.5576.8687.53
Percentage of DisposalGroupIncludingDiscontinuedOperationInterestExpense100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationRevenue

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-06-302021-03-312020-06-302020-03-31
Value20423438
Percentage of DisposalGroupIncludingDiscontinuedOperationRevenue100.0100.0100.0100.0

us-gaap:GainLossOnDerivativeInstrumentsNetPretax

us-gaap:GainLossOnDerivativeInstrumentsNetPretax


Gain
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value127000.0-674000.0500000.0432000.0120000.0-380000.0272000.0-737000.016000.0-450000.0-400000.0-249000.0-1097000.0372000.093000.0377000.0851000.045000.0-1036000.0257000.0-619000.0784000.0-469000.0-42000.0369000.0-2220000.0-33000.0-1252000.0-205000.0-103000.0-23000.0250000.051000.0-530000.0
Percentage of GainLossOnDerivativeInstrumentsNetPretax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GainLossOnDispositionOfIntangibleAssets us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType

us-gaap:GainLossOnDispositionOfIntangibleAssets

us-gaap:OtherIntangibleAssets, us-gaap:SubsequentEvent


Gain
Period End2021-07-08
Value3600000.0
Percentage of GainLossOnDispositionOfIntangibleAssets100.0

us-gaap:GoodwillImpairmentLoss

us-gaap:GoodwillImpairmentLoss


Goodwill
Period End2020-12-312020-09-302020-06-302020-03-312019-06-302019-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value170.00.02620.00.00.00.00.00.00.00.00.00.0
Percentage of GoodwillImpairmentLoss100.00.00.0100.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ImpairmentOfLongLivedAssetsHeldForUse

us-gaap:ImpairmentOfLongLivedAssetsHeldForUse


Impairment
Period End2021-06-30
Value1600000.0
Percentage of ImpairmentOfLongLivedAssetsHeldForUse100.0

us-gaap:IncomeLossFromContinuingOperationsPerBasicAndDilutedShare

us-gaap:IncomeLossFromContinuingOperationsPerBasicAndDilutedShare


Income
Period End2021-03-312020-03-312019-06-302019-03-312018-06-302018-03-31
Value-0.39-2.71-0.33-0.95-0.24-0.86
Percentage of IncomeLossFromContinuingOperationsPerBasicAndDilutedShare100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax


Income
Period End2021-06-302021-03-312020-06-302020-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value216-2.955-5.731-7.947302.4415.8174.575101.871.7993.203
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTax us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:HMHBooksAndMediaSegment


Income
Period End2021-06-302021-03-312020-06-302020-03-31
Value1.95-2.955-5.731-7.947
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTax0.9100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare


Income
Period End2021-03-312020-03-312018-06-302018-03-31
Value-0.02-0.060.050.04
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicAndDilutedShare100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare


Income
Period End2021-06-302020-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.7-0.050.250.020.050.040.080.020.020.03
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare

us-gaap:IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare


Income
Period End2021-06-302020-06-302018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value1.66-0.050.250.020.050.040.080.010.020.03
Percentage of IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value193.322-41.154179.746-20.732-49.62414210.7870.67316-4.1452.683-36.26179.4482.057-13.911-21.91124-12.744-12.5483215-21.67-50.8413150-34.269-91.3089018-17.342
Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

us-gaap:IncreaseDecreaseInContractWithCustomerLiability


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value17-42.231-48.16911945-59.529-40.61818099-39.87-42.0545513-34.715
Percentage of IncreaseDecreaseInContractWithCustomerLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInInterestPayableNet

us-gaap:IncreaseDecreaseInInterestPayableNet


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value6797000.0-6881000.07036000.0-6769000.06936000.0-12000.03679000.0-337000.0107000.0241000.0-227000.070000.0-48000.019000.0117000.095000.05000.0-88000.00-95000.0161000.0-7000.0-1000.000-7000.0-14000.0-128000.053000.057000.0
Percentage of IncreaseDecreaseInInterestPayableNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingAssets

us-gaap:IncreaseDecreaseInOtherOperatingAssets


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value8.6453.851-1.949-2.645141.68-3.4948.081122.771-4.624-4.7567.152-1.6810-8.3944.6313.366-5.183-11.296.713.09-6.214.4234.00.349
Percentage of IncreaseDecreaseInOtherOperatingAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities

us-gaap:IncreaseDecreaseInOtherOperatingLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value5.82-0.72-11.005-0.930.4240.886-9.9957.2468.34-13.571-11.2183.3639.763.151-8.267-6.8648.6683.55-18.043-8.030.3934.5264.415-82.92-6.2587.166-14.712-5.7054.533-2.4299.234-12.445-3.844-2.036
Percentage of IncreaseDecreaseInOtherOperatingLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations

us-gaap:IncreaseDecreaseInPensionAndPostretirementObligations


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-825000.0-855000.08975000.0-3971000.0-453000.0-1108000.0-2039000.0-1436000.0-113000.0-1212000.01558000.0-561000.0-590000.0-1311000.0-2841000.0-1118000.0-1188000.0-1785000.08026000.0-1337000.0-1440000.0-1574000.0-816000.0-1354000.0-1344000.0-1355000.0-6488000.0-3615000.0-3680000.0-2941000.0-3362000.0-4578000.0-3775000.0-3342000.0
Percentage of IncreaseDecreaseInPensionAndPostretirementObligations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInRestructuringReserve

us-gaap:IncreaseDecreaseInRestructuringReserve


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-6.382-8.156-15.31130-2.997-5.3211-0.7160.311-0.059-2.3420.793-1.2770.003-3.259-6.37913-3.5462.8351.1520.797-0.469-0.945-0.462-1.092-1.116-0.222-2.591-0.628-1.769-0.8430.937-1.446-1.407
Percentage of IncreaseDecreaseInRestructuringReserve100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInRoyaltiesPayable

us-gaap:IncreaseDecreaseInRoyaltiesPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value22-12.924-2.3924.5627.081-29.2078.1771015-24.3593.5154.45810-20.2178.203-2.10413-21.804-8.856-0.49622-25.516-9.485.74434-24.875-2.8178.25328-21.1123.7719.03510-17.795
Percentage of IncreaseDecreaseInRoyaltiesPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestPaidDiscontinuedOperations

us-gaap:InterestPaidDiscontinuedOperations


Interest
Period End2021-06-302021-03-312020-06-302020-03-31
Value3.9485.8036.0997.36
Percentage of InterestPaidDiscontinuedOperations100.0100.0100.0100.0

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations

us-gaap:NetCashProvidedByUsedInInvestingActivitiesContinuingOperations


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-03-31
Value324-24.303-28.49-30.364-31.241-35.683-27.676-1.7276-80.574-44.54848-79.88-121.905-24.34821-59.078-131.1223.53672-110.191-198.771-622.213254-42.33
Percentage of NetCashProvidedByUsedInInvestingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations

us-gaap:NetCashProvidedByUsedInOperatingActivitiesContinuingOperations


Net
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-03-31
Value5.613-100.546-19.099-171.968127393-89.862-176.06377201-78.561-96.68696178-44.324-95.878134178-56.027-112.75184298-41.846-92.931-102.544
Percentage of NetCashProvidedByUsedInOperatingActivitiesContinuingOperations100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent

us-gaap:NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value26000.0200000.01039000.0-61000.0-61000.0-61000.0-42000.0-41000.0-42000.0-42000.0-320000.0-320000.0-320000.0-320000.0-871000.0-871000.0-872000.0
Percentage of NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1

us-gaap:NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1


Noncash
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value123000.0-41000.0-40000.0-43000.0288000.0-39000.0-38000.0-38000.0442000.0-35000.0-55000.0-586000.0785000.0-556000.0-541000.0-527000.02980000.0-149000.0-218000.0-410000.04272000.0-302000.0245000.0-295000.04641000.0
Percentage of NoncashOrPartNoncashAcquisitionFixedAssetsAcquired1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:NoncashOrPartNoncashAcquisitionPayablesAssumed1 us-gaap:FairValueByAssetClass

us-gaap:NoncashOrPartNoncashAcquisitionPayablesAssumed1

hmhc:PrePublicationCosts


Noncash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-0.2124.3923.09-1.846-1.945.978-1.819-7.989-3.718-2.759-9.323-3.36429-1.022-0.6341.202172.43-0.0170.413114.0973.121-2.3749.798-2.432-7.3562.7141313-13.957.49817
Percentage of NoncashOrPartNoncashAcquisitionPayablesAssumed1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PropertyPlantAndEquipment


Noncash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-0.21.4520.354-0.642-1.4973.7870.7220.214-0.3452.448-12.035-1.380.201151.492.0054.3193.5890.547-9.2593.64102.1740.1790.4533.3960.749-0.591-0.6313.1363.315-0.7011.182.368
Percentage of NoncashOrPartNoncashAcquisitionPayablesAssumed194.333.111.534.877.263.3-39.7-2.79.312.9436.214.8-6.051.4-145.8-316.2359.320.922.554464.7881.493.253.15.7-19.134.7-30.88.0-23.223.825.05.015.713.4

us-gaap:NotesReduction us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

us-gaap:NotesReduction

us-gaap:DebtInstrumentRedemptionPeriodTwo, us-gaap:SeniorNotes


Notes
Period End2021-06-30
Value2700000.0
Percentage of NotesReduction100.0

us-gaap:OperatingLeaseImpairmentLoss

us-gaap:OperatingLeaseImpairmentLoss


Operating
Period End2021-06-30
Value9300000.0
Percentage of OperatingLeaseImpairmentLoss100.0

us-gaap:OperatingLeaseRightOfUseAssetAmortizationExpense

us-gaap:OperatingLeaseRightOfUseAssetAmortizationExpense


Operating
Period End2021-03-312020-03-31
Value3285000.03632000.0
Percentage of OperatingLeaseRightOfUseAssetAmortizationExpense100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax us-gaap:DerivativeInstrumentRisk

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax

us-gaap:InterestRateContract


Other
Period End2020-09-302020-06-302020-03-31
Value300.0-498400.0500000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax us-gaap:DerivativeInstrumentRisk, us-gaap:SubsequentEventType

us-gaap:InterestRateContract, us-gaap:SubsequentEvent


Other
Period End2020-07-22
Value300000.0
Percentage of OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax0.0

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax

us-gaap:OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax


Other
Period End2021-06-302021-03-31
Value1200000.06400000.0
Percentage of OtherComprehensiveIncomeLossFinalizationOfPensionAndNonPensionPostretirementPlanValuationNetOfTax100.0100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value1304000.06590000.0-9173000.0172000.0993000.0-444000.02042000.0-608000.0-1972000.0-1550000.0-4448000.0576000.0
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax


Other
Period End2021-06-302021-03-312014-06-30
Value-1.522-6.925-1.983
Percentage of OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax100.0100.0100.0

us-gaap:PaymentsForRestructuring us-gaap:RestructuringCostAndReserve

us-gaap:PaymentsForRestructuring

us-gaap:EmployeeSeverance


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value0.00.10.30.40.5580.9870.6111.0442.971-0.0962.0730.7940.6581.8581.7692.682.1412.4431.7251.0791.2051.0950.870.9841.0421.4982.8842.4422.3811.0931.0781.276
Percentage of PaymentsForRestructuring0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsForRestructuring us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

hmhc:SeveranceAndTerminationBenefits, hmhc:TwoThousandAndNineteenRestructuringPlan


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value0.1270.1272.3271.4622.7014.88
Percentage of PaymentsForRestructuring0.00.00.01462.0900.31220.0

hmhc:SeveranceAndTerminationBenefits, hmhc:TwoThousandAndTwentyRestructuringPlan


Payments
Period End2021-06-302021-03-312020-12-31
Value5.2028.02913
Percentage of PaymentsForRestructuring0.00.00.0

us-gaap:EmployeeSeverance, hmhc:TwoThousandAndNineteenRestructuringPlan


Payments
Period End2020-12-31
Value2.438
Percentage of PaymentsForRestructuring0.0

us-gaap:PaymentsForRestructuring us-gaap:RestructuringPlan

hmhc:TwoThousandAndTwentyRestructuringPlan


Payments
Period End2020-09-30
Value33
Percentage of PaymentsForRestructuring33500.0

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation

us-gaap:PaymentsRelatedToTaxWithholdingForShareBasedCompensation


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-03-31
Value00048000.055000.034000.0173000.01756000.077000.020000.020000.01073000.0016000.0645000.0789000.0262000.0371000.001039000.00534000.00124000.0366000.0
Percentage of PaymentsRelatedToTaxWithholdingForShareBasedCompensation0.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.0100.0

us-gaap:PensionAndOtherPostretirementBenefitContributions

us-gaap:PensionAndOtherPostretirementBenefitContributions


Pension
Period End2021-06-302020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value500000.03700000.0006200000.01200000.0007600000.00008000000.00007700000.00006900000.0000-900000.02300000.02300000.02000000.0-3000000.03400000.02600000.02400000.0
Percentage of PensionAndOtherPostretirementBenefitContributions100.0100.00.00.0100.0100.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromDivestitureOfBusinesses us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:ProceedsFromDivestitureOfBusinesses

hmhc:HMHBooksAndMediaSegment


Proceeds
Period End2021-05-10
Value337
Percentage of ProceedsFromDivestitureOfBusinesses100.0

us-gaap:ProceedsFromDivestitureOfBusinesses us-gaap:StatementScenario, us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

srt:ScenarioForecast, hmhc:HMHBooksAndMediaSegment


Proceeds
Period End2021-06-30
Value337
Percentage of ProceedsFromDivestitureOfBusinesses0.0

us-gaap:ProceedsFromIssuanceOfCommonStock

us-gaap:ProceedsFromIssuanceOfCommonStock


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value0410000.00415000.00503000.01000.0521000.01000.0505000.00582000.00681000.00713000.00895000.001084000.001113000.0
Percentage of ProceedsFromIssuanceOfCommonStock0.0100.00.0100.00.0100.0100.0100.0100.0100.00.0100.00.0100.00.0100.00.0100.00.0100.00.0100.0

us-gaap:ProceedsFromLinesOfCredit

us-gaap:ProceedsFromLinesOfCredit


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302012-06-22
Value0.00.00.01500.00.00.00.030
Percentage of ProceedsFromLinesOfCredit0.00.00.0100.00.00.00.00.0100.0

us-gaap:ProceedsFromSaleOfIntangibleAssets us-gaap:FiniteLivedIntangibleAssetsByMajorClass, us-gaap:SubsequentEventType

us-gaap:ProceedsFromSaleOfIntangibleAssets

us-gaap:IntellectualProperty, us-gaap:SubsequentEvent


Proceeds
Period End2021-07-08
Value5000000.0
Percentage of ProceedsFromSaleOfIntangibleAssets100.0

us-gaap:QuantifyingMisstatementInCurrentYearFinancialStatementsAmount us-gaap:ErrorCorrectionsAndPriorPeriodAdjustmentsRestatementByRestatementPeriodAndAmount

us-gaap:QuantifyingMisstatementInCurrentYearFinancialStatementsAmount

hmhc:GoodwillImpairmentCharge


Quantifying
Period End2020-12-31
Value17
Percentage of QuantifyingMisstatementInCurrentYearFinancialStatementsAmount100.0

hmhc:IncomeTaxBenefit


Quantifying
Period End2020-12-31
Value1.0
Percentage of QuantifyingMisstatementInCurrentYearFinancialStatementsAmount5.9

us-gaap:RelatedPartyTransactionAmountsOfTransaction

us-gaap:RelatedPartyTransactionAmountsOfTransaction


Related
Period End2021-06-302021-03-312020-12-31
Value70903-33.4
Percentage of RelatedPartyTransactionAmountsOfTransaction100.0100.0100.0

us-gaap:RepaymentsOfLinesOfCredit

us-gaap:RepaymentsOfLinesOfCredit


Repayments
Period End2020-12-312020-09-302019-12-312018-12-31
Value0.01000.00.0
Percentage of RepaymentsOfLinesOfCredit0.0100.00.00.0

us-gaap:RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent us-gaap:RestructuringPlan

us-gaap:RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent

hmhc:TwoThousandAndTwentyRestructuringPlan


Restructuring
Period End2020-09-30
Value22.0
Percentage of RestructuringAndRelatedCostNumberOfPositionsEliminatedPeriodPercent100.0

us-gaap:RestructuringCharges

us-gaap:RestructuringCharges


Restructuring
Period End2021-06-302020-12-312020-09-302019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value9.8470.09833150.274.431.2211.583.0770.00.01.6171.768333.8756.7553.7653.5531.5771.1621.5630.9851.0572.00.1813.3621.7573.2163.3431.5531.928
Percentage of RestructuringCharges100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestructuringCharges us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

hmhc:SeveranceAndTerminationBenefits, hmhc:TwoThousandAndTwentyRestructuringPlan


Restructuring
Period End2020-12-312020-09-30
Value0.09833
Percentage of RestructuringCharges100.0100.0

us-gaap:RestructuringCharges us-gaap:RestructuringPlan

hmhc:TwoThousandAndTwentyRestructuringPlan


Restructuring
Period End2020-12-31
Value33
Percentage of RestructuringCharges34329.6

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross

us-gaap:AdditionalPaidInCapital


Stock
Period End2021-06-302021-03-312020-06-302020-03-312019-09-302019-03-312018-06-302018-03-31
Value-2000.0-13000.0-1000.0-10000.0-1000.0-5000.0-1000.0-2000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-312020-06-302020-03-312019-09-302019-03-312018-06-302018-03-31
Value2000.013000.01000.010000.01000.05000.01000.02000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross-100.0-100.0-100.0-100.0-100.0-100.0-100.0-100.0

us-gaap:ValuationAllowancesAndReservesPeriodIncreaseDecrease us-gaap:ValuationAllowancesAndReservesType

us-gaap:ValuationAllowancesAndReservesPeriodIncreaseDecrease

us-gaap:Royalty


Valuation
Period End2021-06-302021-03-31
Value0.00.1
Percentage of ValuationAllowancesAndReservesPeriodIncreaseDecrease0.0100.0

hmhc:ContingentLiabilityRelatedToSuretyBond

hmhc:ContingentLiabilityRelatedToSuretyBond


Contingent
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.91.21.41.41.41.32.50.80.84.44.44.31.32.52.52.52.54.04.14.19.39.49.49.48.9121116232323
Percentage of ContingentLiabilityRelatedToSuretyBond100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:ContractWithCustomerDeferredSalesCommission

hmhc:ContractWithCustomerDeferredSalesCommission


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-01-01
Value323030323128293322212224
Percentage of ContractWithCustomerDeferredSalesCommission100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxAssetOperatingLossCarryforwardsAndOtherCarryforwards

hmhc:DeferredTaxAssetOperatingLossCarryforwardsAndOtherCarryforwards


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value326272228229199927140
Percentage of DeferredTaxAssetOperatingLossCarryforwardsAndOtherCarryforwards100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxAssetsDeferredInterest

hmhc:DeferredTaxAssetsDeferredInterest


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value226259261280428416
Percentage of DeferredTaxAssetsDeferredInterest100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxAssetsOperatingLeaseLiabilities

hmhc:DeferredTaxAssetsOperatingLeaseLiabilities


Deferred
Period End2020-12-312019-12-31
Value3335
Percentage of DeferredTaxAssetsOperatingLeaseLiabilities100.0100.0

hmhc:DeferredTaxLiabilitiesDefiniteLivedIntangibleAssets

hmhc:DeferredTaxLiabilitiesDefiniteLivedIntangibleAssets


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value21253045826179
Percentage of DeferredTaxLiabilitiesDefiniteLivedIntangibleAssets100.0100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxLiabilitiesDepreciationAndAmortization

hmhc:DeferredTaxLiabilitiesDepreciationAndAmortization


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4548344375345473
Percentage of DeferredTaxLiabilitiesDepreciationAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxLiabilitiesIndefiniteLivedIntangibleAssets

hmhc:DeferredTaxLiabilitiesIndefiniteLivedIntangibleAssets


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value5389766271140132
Percentage of DeferredTaxLiabilitiesIndefiniteLivedIntangibleAssets100.0100.0100.0100.0100.0100.0100.0

hmhc:DeferredTaxLiabilitiesOperatingLeaseAssets

hmhc:DeferredTaxLiabilitiesOperatingLeaseAssets


Deferred
Period End2020-12-312019-12-31
Value3032
Percentage of DeferredTaxLiabilitiesOperatingLeaseAssets100.0100.0

hmhc:DefinedBenefitPlanUnfundedStatusOfPlan

hmhc:DefinedBenefitPlanUnfundedStatusOfPlan


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value181615-21.903-24.012-25.567-28.537
Percentage of DefinedBenefitPlanUnfundedStatusOfPlan100.0100.0100.0100.0100.0100.0100.0

hmhc:DefinedBenefitPlanUnfundedStatusOfPlan us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value252329-24.133-28.956
Percentage of DefinedBenefitPlanUnfundedStatusOfPlan141.6141.7185.4110.2120.6

hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedRoyaltiesCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedRoyaltiesCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value2117
Percentage of DisposalGroupIncludingDiscontinuedOperationAccruedRoyaltiesCurrent100.0100.0

hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedSalariesAndWagesCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:DisposalGroupIncludingDiscontinuedOperationAccruedSalariesAndWagesCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value453000.0221000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationAccruedSalariesAndWagesCurrent100.0100.0

hmhc:DisposalGroupIncludingDiscontinuedOperationAdvanceRoyaltiesNetCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:DisposalGroupIncludingDiscontinuedOperationAdvanceRoyaltiesNetCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value4040
Percentage of DisposalGroupIncludingDiscontinuedOperationAdvanceRoyaltiesNetCurrent100.0100.0

hmhc:DisposalGroupIncludingDiscontinuedOperationPrepublicationCostsNetCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:DisposalGroupIncludingDiscontinuedOperationPrepublicationCostsNetCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value337000.0329000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationPrepublicationCostsNetCurrent100.0100.0

hmhc:DisposalGroupIncludingDiscontinuedOperationSubjectToCustomaryWorkingCapitalAdjustmentExpectedPayment us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:DisposalGroupIncludingDiscontinuedOperationSubjectToCustomaryWorkingCapitalAdjustmentExpectedPayment

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-05-10
Value7800000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationSubjectToCustomaryWorkingCapitalAdjustmentExpectedPayment100.0

hmhc:FilmAndMediaGross

hmhc:FilmAndMediaGross


Film
Period End2020-12-312019-12-312018-12-312017-12-31
Value2922148.056
Percentage of FilmAndMediaGross100.0100.0100.0100.0

hmhc:NonFinancialAssetsFairValueDisclosure

hmhc:NonFinancialAssetsFairValueDisclosure


Non
Period End2020-12-312020-09-302020-06-302020-03-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4374544544540.00.0650.03.84.2
Percentage of NonFinancialAssetsFairValueDisclosure100.0100.0100.0100.00.00.0100.00.0100.0100.0

hmhc:NonFinancialAssetsFairValueDisclosure us-gaap:FairValueByAssetClass

us-gaap:Goodwill


Non
Period End2020-12-312020-09-302020-06-302020-03-31
Value437454454454
Percentage of NonFinancialAssetsFairValueDisclosure100.0100.0100.0100.0

hmhc:NonFinancialAssetsFairValueDisclosure us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:Goodwill, us-gaap:FairValueInputsLevel3


Non
Period End2020-12-312020-09-302020-06-302020-03-31
Value437454454454
Percentage of NonFinancialAssetsFairValueDisclosure100.0100.0100.0100.0

hmhc:NonFinancialAssetsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel3


Non
Period End2020-12-312020-09-302020-06-302020-03-312018-12-312017-12-312014-12-312013-12-31
Value4374544544540.00.03.84.2
Percentage of NonFinancialAssetsFairValueDisclosure100.0100.0100.0100.00.00.0100.0100.0

hmhc:OperatingLossCarryForwardsReducedReserveOfUncertainTaxPositions

hmhc:OperatingLossCarryForwardsReducedReserveOfUncertainTaxPositions


Operating
Period End2020-12-31
Value123
Percentage of OperatingLossCarryForwardsReducedReserveOfUncertainTaxPositions100.0

hmhc:PercentageOfEmployeeBaseEligibleToParticipateInVoluntaryRetirementProgram us-gaap:RestructuringPlan, us-gaap:RetirementPlanType

hmhc:PercentageOfEmployeeBaseEligibleToParticipateInVoluntaryRetirementProgram

hmhc:TwoThousandAndTwentyRestructuringPlan, hmhc:RetirementIncentiveProgram


Percentage
Period End2020-09-04
Value5.0
Percentage of PercentageOfEmployeeBaseEligibleToParticipateInVoluntaryRetirementProgram100.0

hmhc:PercentageOfRevenueRecognitionFromContractsWithCustomers

hmhc:PercentageOfRevenueRecognitionFromContractsWithCustomers


Percentage
Period End2020-12-312019-06-30
Value73.00.76
Percentage of PercentageOfRevenueRecognitionFromContractsWithCustomers100.0100.0

hmhc:PrePublicationCostsNet

hmhc:PrePublicationCostsNet


Pre
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value179191203222239256268290311321323325341335324314317318314320324323321326326232236249261267269
Percentage of PrePublicationCostsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hmhc:TotalLeaseAssets

hmhc:TotalLeaseAssets


Total
Period End2020-12-312019-12-31
Value126132
Percentage of TotalLeaseAssets100.0100.0

hmhc:UnrecognizedTaxBenefitsExcludingInterestAndPenalties

hmhc:UnrecognizedTaxBenefitsExcludingInterestAndPenalties


Unrecognized
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value15151515151515151515150.20.915161662
Percentage of UnrecognizedTaxBenefitsExcludingInterestAndPenalties100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsReceivableGross

us-gaap:AccountsReceivableGross


Accounts
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value171204224224238288283358
Percentage of AccountsReceivableGross100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccountsReceivableNet

us-gaap:AccountsReceivableNet


Accounts
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value152184203201216256255318
Percentage of AccountsReceivableNet100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedRoyaltiesCurrent

us-gaap:AccruedRoyaltiesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value42215052494072685942666567537268695372838560859692558085795065
Percentage of AccruedRoyaltiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedSalariesCurrent

us-gaap:AccruedSalariesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value351421372814546941175050391454564319413933274565361759
Percentage of AccruedSalariesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312012-12-31
Value-90000.0-90000.0-99000.0-108000.0-90000.0-147000.0-89000.013000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value-18000.0-1005000.02381000.0-1160000.0-6108000.0-3641000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value483941394131241018
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax us-gaap:RegulatoryLiability

us-gaap:PostretirementBenefitCosts


Accumulated
Period End2020-12-312019-12-31
Value1.434-1.345
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax2.9-3.4

us-gaap:AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value44-35.01-36.779-33.456-35.19
Percentage of AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax90.3-88.1-88.5-84.7-85.3

us-gaap:AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax


Accumulated
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value-6650000.0-6420000.0-5909000.0-5753000.0-5862000.0-4642000.0-2502000.0-2473000.0-2877000.0
Percentage of AccumulatedOtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdvanceRoyaltiesNoncurrent

us-gaap:AdvanceRoyaltiesNoncurrent


Advance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value2.1372.0644241434144484947475049474650484643464744444547474649515146
Percentage of AdvanceRoyaltiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivable

us-gaap:AllowanceForDoubtfulAccountsReceivable


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value3.53.74.03.94.13.53.0
Percentage of AllowanceForDoubtfulAccountsReceivable100.0100.0100.0100.0100.0100.0100.0

us-gaap:AllowanceForDoubtfulAccountsReceivable us-gaap:ValuationAllowancesAndReservesType

hmhc:AllowanceForSalesReturn


Allowance
Period End2020-12-312019-12-312018-12-312017-12-31
Value14161820
Percentage of AllowanceForDoubtfulAccountsReceivable364.4556.00.00.0

us-gaap:AllowanceForCreditLoss


Allowance
Period End2020-12-312019-12-312018-12-312017-12-31
Value3.9893.0152.1732.508
Percentage of AllowanceForDoubtfulAccountsReceivable99.7100.50.00.0

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent


Allowance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value9.68.21819181719252018202019202326221922312829323330292746403640
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetsFairValueDisclosure

us-gaap:AssetsFairValueDisclosure


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1241522622501182352762904.8366228012826812021963512726516545173373402295540725565155254370
Percentage of AssetsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByAssetClass

us-gaap:DerivativeFinancialInstrumentsAssets


Assets
Period End2020-12-312018-03-312017-12-312017-09-302017-06-302016-03-31
Value0.4660.2630.3510.5160.4960.454
Percentage of AssetsFairValueDisclosure0.20.30.20.31.40.3

us-gaap:MoneyMarketFunds


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1241522622501182352762904.83651228932278115120351131849945105175256295540438245101154259
Percentage of AssetsFairValueDisclosure100.0100.099.8100.0100.0100.0100.0100.0100.082.281.473.185.196.857.161.198.688.769.660.0100.060.847.063.6100.0100.060.543.465.460.569.8

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:BankTimeDeposits, us-gaap:FairValueInputsLevel1


Assets
Period End2021-06-302021-03-312020-12-312019-12-31
Value22181919
Percentage of AssetsFairValueDisclosure17.812.47.37.1

us-gaap:BankTimeDeposits, us-gaap:FairValueInputsLevel2


Assets
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value2120191917102324108.21933134336415052635812024211722381354
Percentage of AssetsFairValueDisclosure8.417.38.27.16.2213.037.28.88.331.024.216.66.9122.428.315.530.5113.536.715.729.98.14.02.44.024.55.314.7

us-gaap:DerivativeFinancialInstrumentsAssets, us-gaap:FairValueInputsLevel2


Assets
Period End2020-12-312018-03-312017-12-312017-09-302017-06-302016-03-31
Value0.4660.2630.3510.5160.4960.454
Percentage of AssetsFairValueDisclosure0.20.30.20.31.40.3

us-gaap:MoneyMarketFunds, us-gaap:FairValueInputsLevel1


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1241522622501182352762904.83651228932278115120351131849945105175256295540438245101154259
Percentage of AssetsFairValueDisclosure100.0100.099.8100.0100.0100.0100.0100.0100.082.281.473.185.196.857.161.198.688.769.660.0100.060.847.063.6100.0100.060.543.465.460.569.8

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1241522622501182352762904.8365125310822781311353511919910745165184265295540531346132202316
Percentage of AssetsFairValueDisclosure100.0100.099.8100.0100.0100.0100.0100.0100.082.290.384.885.196.865.068.898.693.775.064.8100.095.749.465.9100.0100.073.361.285.479.385.2

us-gaap:FairValueInputsLevel2


Assets
Period End2020-12-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-03-312015-12-312015-09-302014-12-312014-09-302014-06-302014-03-312013-12-31
Value0.4661127193.9482.58170610.4968.00966587.453189137194219225254
Percentage of AssetsFairValueDisclosure0.217.89.715.214.93.235.031.21.46.325.035.24.350.634.126.738.814.620.714.8

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent


Assets
Period End2021-03-312020-12-312018-09-302017-12-31
Value140160125126
Percentage of AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0100.0100.0

us-gaap:AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:HMHBooksAndMediaSegment


Assets
Period End2021-03-312020-12-31
Value140160
Percentage of AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0

us-gaap:BuildingsAndImprovementsGross

us-gaap:BuildingsAndImprovementsGross


Buildings
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value11109.4159.8679.8679.8239.7239.505
Percentage of BuildingsAndImprovementsGross100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CapitalLeasesFutureMinimumPaymentsDueCurrent us-gaap:FairValueByAssetClass

us-gaap:CapitalLeasesFutureMinimumPaymentsDueCurrent

us-gaap:PropertyPlantAndEquipment


Capital
Period End2020-12-31
Value100000.0
Percentage of CapitalLeasesFutureMinimumPaymentsDueCurrent100.0

us-gaap:CapitalizedComputerSoftwareGross

us-gaap:CapitalizedComputerSoftwareGross


Capitalized
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value641598563539497418350294
Percentage of CapitalizedComputerSoftwareGross100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CapitalizedContractCostNet

us-gaap:CapitalizedContractCostNet


Capitalized
Period End2021-06-302021-03-312020-12-312020-09-302019-12-31
Value161414135.6
Percentage of CapitalizedContractCostNet100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerAssetNet

us-gaap:ContractWithCustomerAssetNet


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-01
Value715000.0596000.0580000.027000.077000.0294000.0109000.0228000.070000.0298000.074000.04177000.04128000.02620000.01092000.0
Percentage of ContractWithCustomerAssetNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ContractWithCustomerLiability

us-gaap:ContractWithCustomerLiability


Contract
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312018-01-01
Value880863905953834788848888707607647689641627665
Percentage of ContractWithCustomerLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrumentCarryingAmount

us-gaap:DebtInstrumentCarryingAmount


Debt
Period End2020-12-312019-12-31
Value667686
Percentage of DebtInstrumentCarryingAmount100.0100.0

us-gaap:DebtInstrumentFaceAmount us-gaap:DebtInstrumentRedemptionPeriod, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentFaceAmount

us-gaap:DebtInstrumentRedemptionPeriodOne, hmhc:TermLoan


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-11-222017-12-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value380380380380380380380380250250250250250250250250
Percentage of DebtInstrumentFaceAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxAssetsNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value2415000.02415000.02415000.02520000.02520000.02520000.0
Percentage of DeferredIncomeTaxAssetsNet100.0100.0100.0100.0100.0100.0

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredIncomeTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value160204147151228236266304
Percentage of DeferredIncomeTaxLiabilities100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredLongTermLiabilityCharges

us-gaap:DeferredLongTermLiabilityCharges


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value564542562596556514542574444373395412400401419440431420436464444421440459407357370379267182189
Percentage of DeferredLongTermLiabilityCharges100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredRevenueCurrent

us-gaap:DeferredRevenueCurrent


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value316320342356277274305314263234251276240225275285242251272277209211231234180154157162134105107
Percentage of DeferredRevenueCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsInProcessResearchAndDevelopment

us-gaap:DeferredTaxAssetsInProcessResearchAndDevelopment


Deferred
Period End2020-12-312019-12-312018-12-312017-12-31
Value12106.0380.335
Percentage of DeferredTaxAssetsInProcessResearchAndDevelopment100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value8.2636.7699.0648.87512122621
Percentage of DeferredTaxAssetsOther100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign


Deferred
Period End2020-12-31
Value2400000.0
Percentage of DeferredTaxAssetsTaxCreditCarryforwardsForeign100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value6.5256.1525.835.8724.557202317
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsOther100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value6.8796.6248.2946.9771210
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value4.484.4754.3386.2859.98810
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPostretirementBenefits100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost

us-gaap:DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value2806000.03298000.05415000.03992000.07808000.08046000.0
Percentage of DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value3941394064666164
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccruals100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value14111311812218214675109
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredRent100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312015-12-312014-12-31
Value9877000.07709000.06170000.081000.0148000.0269000.0
Percentage of DeferredTaxLiabilitiesOther100.0100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesOtherComprehensiveIncome

us-gaap:DeferredTaxLiabilitiesOtherComprehensiveIncome


Deferred
Period End2020-12-31
Value2400000.0
Percentage of DeferredTaxLiabilitiesOtherComprehensiveIncome100.0

us-gaap:DefinedBenefitPensionPlanCurrentAndNoncurrentLiabilities

us-gaap:DefinedBenefitPensionPlanCurrentAndNoncurrentLiabilities


Defined
Period End2020-12-312019-12-31
Value2523
Percentage of DefinedBenefitPensionPlanCurrentAndNoncurrentLiabilities100.0100.0

us-gaap:DefinedBenefitPensionPlanLiabilitiesCurrent

us-gaap:DefinedBenefitPensionPlanLiabilitiesCurrent


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1593000.01593000.01593000.01571000.01571000.01571000.01571000.01512000.01512000.01512000.01512000.01618000.01618000.01618000.01618000.01928000.01928000.01928000.01928000.01910000.01910000.01910000.01910000.02037000.02037000.02037000.02037000.02141000.02141000.02141000.02141000.0
Percentage of DefinedBenefitPensionPlanLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPensionPlanLiabilitiesNoncurrent

us-gaap:DefinedBenefitPensionPlanLiabilitiesNoncurrent


Defined
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value15172419232323272829292323232426272828202122231617171816192124
Percentage of DefinedBenefitPensionPlanLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value179169162176177
Percentage of DefinedBenefitPlanAccumulatedBenefitObligation100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value-44219000.0-35010000.0-36779000.0-33456000.0-35190000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax us-gaap:RegulatoryLiability

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax

us-gaap:PostretirementBenefitCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value-1050000.0-1771000.0-3856000.0-1328000.0-2588000.0-3777000.0-6087000.0-2476000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax us-gaap:RegulatoryLiability

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax

us-gaap:PostretirementBenefitCosts


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value384000.0-426000.0-467000.0222000.01561000.03494000.04876000.06257000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

hmhc:AccumulatedPostretirementBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2.20.0310.0420.0360.041
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate100.0100.0100.0100.0100.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value3.10.0420.0360.0410.0440.039
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate140.9135.585.7113.9107.30.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2.20.0310.0420.0360.04
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate100.0100.0100.0100.097.6

us-gaap:DefinedBenefitPlanBenefitObligation

us-gaap:DefinedBenefitPlanBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value181615212425282629
Percentage of DefinedBenefitPlanBenefitObligation100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value179169162176177174
Percentage of DefinedBenefitPlanBenefitObligation990.11015.11025.1805.6738.4681.0

us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedAmortizationNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-42000.0-35000.0122000.0690000.0
Percentage of DefinedBenefitPlanExpectedAmortizationNextFiscalYear100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value-3389000.0-2325000.0-1028000.0-1420000.0
Percentage of DefinedBenefitPlanExpectedAmortizationNextFiscalYear8069.06642.9-842.6-205.8

us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-31
Value3389000.02325000.01028000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear100.0100.0100.0

us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-31
Value-42000.0
Percentage of DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value5.6865.625.7787.094
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value61636463
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter1089.41126.21111.8898.2

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.5551.5711.5121.617
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value14121214
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths902.3801.4852.6895.1

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.321.2981.3081.517
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value13131313
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive1011.81011.21005.3868.2

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.3891.3521.3551.546
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value12131314
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour920.7972.7973.1964.6

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.4371.4091.4091.573
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value12121412
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree875.5917.21037.0804.8

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1.4881.4851.4591.605
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value12141212
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo861.4981.3876.1795.9

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value1600000.01600000.01500000.01600000.0
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear100.0100.0100.0100.0

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value3300000.02400000.000
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear206.2150.00.00.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value153145132152148150165167
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories

hmhc:CorporateBonds


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4637404243444738
Percentage of DefinedBenefitPlanFairValueOfPlanAssets30.126.030.528.229.129.628.822.8

hmhc:EmergingMarketsEquity


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value8.2595.5374.6666.0045.3114.6575.7631.55
Percentage of DefinedBenefitPlanFairValueOfPlanAssets5.43.83.53.93.63.13.50.9

hmhc:GovernmentBonds


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2820192419172220
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18.813.915.015.913.212.013.512.1

hmhc:InternationalFixedIncome


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4.4855.7414.1614.7384.8815.8526.612.767
Percentage of DefinedBenefitPlanFairValueOfPlanAssets2.93.93.13.13.33.94.01.7

hmhc:NonUsEquitySecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1512111412121420
Percentage of DefinedBenefitPlanFairValueOfPlanAssets10.18.68.79.48.68.18.912.1

hmhc:UsEquity


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value2728232930262841
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18.119.918.019.520.717.917.224.9

us-gaap:AssetBackedSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.813.2552.7731.7822.1011.8661.5340.7
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.52.22.11.21.41.20.90.4

us-gaap:CashAndCashEquivalents


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1.9141.4130.0850.8350.8621.1481.4361.619
Percentage of DefinedBenefitPlanFairValueOfPlanAssets1.21.00.10.50.60.80.91.0

us-gaap:CommercialMortgageBackedSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.6041.931.92.071.9312.1152.2910.513
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.41.31.41.41.31.41.40.3

us-gaap:HedgeFunds


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value8.2287.0436.6627.2468.51814157.017
Percentage of DefinedBenefitPlanFairValueOfPlanAssets5.44.85.04.85.79.79.24.2

us-gaap:MortgageBackedSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value0.0097.9437.2488.6217.9878.7999.74210
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.05.55.55.75.45.95.96.4

us-gaap:OtherDebtSecurities


Defined
Period End2020-12-312019-12-31
Value0.3641.537
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.21.1

us-gaap:RealEstate


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value10119.4489.8489.4728.9298.4726.485
Percentage of DefinedBenefitPlanFairValueOfPlanAssets7.08.07.16.56.45.95.13.9

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FinancialInstrument

hmhc:CorporateBonds, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4637404243
Percentage of DefinedBenefitPlanFairValueOfPlanAssets30.126.030.528.229.1

hmhc:EmergingMarketsEquity, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value8.2595.5374.6666.0045.311
Percentage of DefinedBenefitPlanFairValueOfPlanAssets5.43.83.53.93.6

hmhc:GovernmentBonds, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2820192419
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18.813.915.015.913.2

hmhc:InternationalFixedIncome, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4.4855.7414.1614.7384.881
Percentage of DefinedBenefitPlanFairValueOfPlanAssets2.93.93.13.13.3

hmhc:NonUsEquitySecurities, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1512111412
Percentage of DefinedBenefitPlanFairValueOfPlanAssets10.18.68.79.48.6

hmhc:UsEquity, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2728232930
Percentage of DefinedBenefitPlanFairValueOfPlanAssets18.119.918.019.520.7

us-gaap:AssetBackedSecurities, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.813.2552.7731.7822.101
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.52.22.11.21.4

us-gaap:CashAndCashEquivalents, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1.9141.4130.0850.8350.862
Percentage of DefinedBenefitPlanFairValueOfPlanAssets1.21.00.10.50.6

us-gaap:CommercialMortgageBackedSecurities, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.6041.931.92.071.931
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.41.31.41.41.3

us-gaap:HedgeFunds, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value8.2287.0436.6627.2468.518
Percentage of DefinedBenefitPlanFairValueOfPlanAssets5.44.85.04.85.7

us-gaap:MortgageBackedSecurities, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value0.0097.9437.2488.6217.987
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.05.55.55.75.4

us-gaap:OtherDebtSecurities, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-31
Value0.3641.537
Percentage of DefinedBenefitPlanFairValueOfPlanAssets0.21.1

us-gaap:RealEstate, hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value10119.4489.8489.472
Percentage of DefinedBenefitPlanFairValueOfPlanAssets7.08.07.16.56.4

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:FinancialInstrument

hmhc:NotSubjectToLeveling


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value153145132152148
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value153145132152148150
Percentage of DefinedBenefitPlanFairValueOfPlanAssets100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear

hmhc:AccumulatedPostretirementBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value5.50.0580.0610.0630.066
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear100.0100.0100.0100.0100.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value5.80.0610.0630.0660.0690.069
Percentage of DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear105.5105.2103.3104.8104.50.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation

hmhc:AccumulatedBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value179169162176177
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value153145132152148150165151
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation

hmhc:ProjectedBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value179169162176177
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation100.0100.0100.0100.0100.0

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanPlanAssetsTargetAllocationPercentage

hmhc:RealEstateInvestmentsTrust, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value5.00.060.040.04
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage100.0100.0100.0100.0

us-gaap:EquitySecurities, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value34.00.340.340.34
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage680.0566.7850.0850.0

us-gaap:FixedIncomeSecurities, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value56.00.560.560.56
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage1120.0933.31400.01400.0

us-gaap:HedgeFunds, us-gaap:PensionPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-31
Value5.00.040.0550.055
Percentage of DefinedBenefitPlanPlanAssetsTargetAllocationPercentage100.066.7137.5137.5

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1 us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanUltimateHealthCareCostTrendRate1

hmhc:AccumulatedPostretirementBenefitObligation


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4.50.0450.0450.0450.045
Percentage of DefinedBenefitPlanUltimateHealthCareCostTrendRate1100.0100.0100.0100.0100.0

us-gaap:OtherPostretirementBenefitPlansDefinedBenefit


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value4.50.0450.0450.0450.0450.045
Percentage of DefinedBenefitPlanUltimateHealthCareCostTrendRate1100.0100.0100.0100.0100.00.0

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations us-gaap:DefinedBenefitPlanByPlanAssetCategories

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations

us-gaap:EquitySecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value33.50.3260.3020.3290.3290.2940.2970.378
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FixedIncomeSecurities


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value52.70.5450.5760.5530.5360.5480.5510.437
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations157.3167.2190.7168.1162.9186.4185.5115.6

us-gaap:OtherInvestments


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value6.80.0490.0510.0530.0710.0980.1010.057
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations20.315.016.916.121.633.334.015.1

us-gaap:RealEstate


Defined
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value7.00.080.0710.0650.0640.060.0510.039
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations20.924.523.519.819.520.417.210.3

us-gaap:DerivativeNotionalAmount us-gaap:DerivativeInstrumentRisk

us-gaap:DerivativeNotionalAmount

hmhc:ForeignExchangeForwardContract


Derivative
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value151514129.713151515
Percentage of DerivativeNotionalAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value4364
Percentage of DisposalGroupIncludingDiscontinuedOperationAccountsNotesAndLoansReceivableNet100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value7.98910
Percentage of DisposalGroupIncludingDiscontinuedOperationAccountsPayableCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value2426
Percentage of DisposalGroupIncludingDiscontinuedOperationIntangibleAssetsCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationInventoryCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value2321
Percentage of DisposalGroupIncludingDiscontinuedOperationInventoryCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value3144000.03096000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherCurrentAssets100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value2267000.02460000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationOtherCurrentLiabilities100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value713000.0655000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationPrepaidAndOtherAssetsCurrent100.0100.0

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

us-gaap:DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent

hmhc:HMHBooksAndMediaSegment


Disposal
Period End2021-03-312020-12-31
Value4193000.04401000.0
Percentage of DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentCurrent100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions us-gaap:AwardType

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions

us-gaap:RestrictedStockUnitsRSU


Employee
Period End2020-12-312017-12-312016-12-312015-12-31
Value11127.33.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions


Employee
Period End2020-12-31
Value600000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions100.0

us-gaap:FinanceLeaseRightOfUseAsset

us-gaap:FinanceLeaseRightOfUseAsset


Finance
Period End2020-12-312019-12-312018-12-31
Value100000.0300000.0700000.0
Percentage of FinanceLeaseRightOfUseAsset100.0100.0100.0

us-gaap:FinancialLiabilitiesFairValueDisclosure

us-gaap:FinancialLiabilitiesFairValueDisclosure


Financial
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value0.3080.3740.1560.3181.7071.1131.9161.250.6020.5340.580.6491.1595.1976.92412129.6693.9814.5530.4811.91.371.337
Percentage of FinancialLiabilitiesFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinancialLiabilitiesFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel2


Financial
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value0.3080.3740.1560.3181.7071.1131.9161.250.6020.5340.580.6491.1595.1976.92412129.6693.9814.5530.4811.91.371.337
Percentage of FinancialLiabilitiesFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinancialLiabilitiesFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByLiabilityClass

us-gaap:FairValueInputsLevel2, us-gaap:DerivativeFinancialInstrumentsLiabilities


Financial
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-03-312016-12-312016-09-302016-06-302015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.3080.3740.1560.040.2840.1270.6530.5340.580.6490.450.8160.0290.1650.340.0920.4811.91.37
Percentage of FinancialLiabilitiesFairValueDisclosure100.0100.0100.012.616.611.434.1100.0100.0100.08.711.80.21.38.52.0100.0100.0100.0

us-gaap:FinancialLiabilitiesFairValueDisclosure us-gaap:FairValueByLiabilityClass

us-gaap:DerivativeFinancialInstrumentsLiabilities


Financial
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-03-312016-12-312016-09-302016-06-302015-12-312015-09-302015-06-302015-03-312014-12-31
Value0.3080.3740.1560.040.2840.1270.6530.5340.580.6490.450.8160.0290.1650.340.0920.4811.91.37
Percentage of FinancialLiabilitiesFairValueDisclosure100.0100.0100.012.616.611.434.1100.0100.0100.08.711.80.21.38.52.0100.0100.0100.0

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value141114011526151415031492148014681455144314281413140113861369135013321313129212681248122712041177115011271100107210441016983
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization us-gaap:FiniteLivedIntangibleAssetsByMajorClass

hmhc:PublishingRights


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value103610331159115411491145113911331126112011121104109610881078106710561045103110171002988970951931912889864839814783
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization73.473.876.076.276.576.776.977.277.477.677.978.178.278.578.779.079.379.679.980.280.380.580.680.881.081.080.880.680.480.179.7

us-gaap:CustomerRelatedIntangibleAssets


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value318315313310307305302299295291287283279276271267264259253247242237231225218214211208205202199
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization22.622.520.520.520.520.420.420.420.320.220.220.120.019.919.919.819.919.719.619.519.419.319.319.119.019.019.219.419.619.920.3

us-gaap:TrademarksAndTradeNames


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-30
Value56515349464238363330282525221916119.1456.9613.6482.9632.281.5960.9120.228
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization4.03.73.53.33.12.92.62.52.32.12.01.81.81.61.41.20.90.70.50.30.20.20.10.10.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value899710611512313222
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive100.0100.0100.0100.0100.0100.0100.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value65718111312539
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive73.473.676.998.2101.529.7

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

hmhc:PublishingRights


Finite
Period End2020-12-312019-12-31
Value1120
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths100.0100.0

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value10101316182112
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths88.853.00.00.00.00.00.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value14101012122.737
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths123.854.20.00.00.00.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value8.3158.5288.9399.1198.9879.2616.488
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFive100.0100.0100.0100.0100.0100.0100.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value6.4379.7551012122.737
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFive77.4114.4121.5135.6137.629.6

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value8.5039.9799.1199.329.261139.053
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFour100.0100.0100.0100.0100.0100.0100.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value6.715101012122.737
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFour79.0108.8119.1132.6133.520.9

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

hmhc:PublishingRights


Finite
Period End2020-12-312019-12-31
Value1.3077.569
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree100.0100.0

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value9.954109.329.594131510
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree761.6134.20.00.00.00.00.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value6.808101012122.737
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree520.9143.50.00.00.00.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

hmhc:PublishingRights


Finite
Period End2020-12-312019-12-31
Value7.56911
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo100.0100.0

us-gaap:OtherIntangibleAssets


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312013-12-31
Value10109.59413151811
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo133.989.00.00.00.00.00.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value10101012122.737
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo140.293.30.00.00.00.0

us-gaap:FiniteLivedIntangibleAssetsGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass

us-gaap:FiniteLivedIntangibleAssetsGross

hmhc:PublishingRights


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value105010501180118011801180118011801180118011801180118011801180118011801180118011801180118011801180
Percentage of FiniteLivedIntangibleAssetsGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CustomerRelatedIntangibleAssets


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value448448449449449449449449449449444444444444444442442442442442442442442283
Percentage of FiniteLivedIntangibleAssetsGross42.742.738.138.138.138.138.138.138.138.137.737.737.737.737.737.537.537.537.537.537.537.537.524.0

us-gaap:TrademarksAndTradeNames


Finite
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value13313316416416416416416416416416416419419419419419419419454545454
Percentage of FiniteLivedIntangibleAssetsGross12.712.713.913.913.913.913.913.913.913.913.913.916.516.516.516.516.516.516.54.64.64.64.6

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss


Goodwill
Period End2021-06-302021-03-312020-12-312020-09-302014-12-312014-09-302014-06-302013-12-31
Value2792792792621442144214421442
Percentage of GoodwillImpairedAccumulatedImpairmentLoss100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsMaximumExposure

us-gaap:GuaranteeObligationsMaximumExposure


Guarantee
Period End2021-03-312020-12-312020-09-30
Value4.71011
Percentage of GuaranteeObligationsMaximumExposure100.0100.0100.0

us-gaap:IntangibleAssetsGrossExcludingGoodwill

us-gaap:IntangibleAssetsGrossExcludingGoodwill


Intangible
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302018-12-31
Value179217921954195419541954195419541949
Percentage of IntangibleAssetsGrossExcludingGoodwill100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestPayableCurrent

us-gaap:InterestPayableCurrent


Interest
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value104.136113.981103.8143.8260.1470.4840.3770.1360.3630.2930.3410.3220.2050.110.1050.1930.1060.1060.1060.1060.1060.2010.040.0470.0480.0480.0480.055
Percentage of InterestPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InventoryFinishedGoodsNetOfReserves

us-gaap:InventoryFinishedGoodsNetOfReserves


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value136165155170230258203202257250162161201192145152192197157164209210166179222201178177
Percentage of InventoryFinishedGoodsNetOfReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InventoryRawMaterialsNetOfReserves

us-gaap:InventoryRawMaterialsNetOfReserves


Inventory
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value119.956218.51610138.7693.6515.284114.495.1849.49114.5425.7367.55125.1495.177
Percentage of InventoryRawMaterialsNetOfReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InventoryWorkInProcessNetOfReserves

us-gaap:InventoryWorkInProcessNetOfReserves


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value8.71710115.6516.5837.2039.9569.418101121
Percentage of InventoryWorkInProcessNetOfReserves100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LandAndLandImprovements

us-gaap:LandAndLandImprovements


Land
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value4939000.04939000.04923000.04923000.04923000.04819000.04717000.04717000.0
Percentage of LandAndLandImprovements100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths


Lessee
Period End2020-12-31
Value24
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths100.0

us-gaap:LettersOfCreditOutstandingAmount

us-gaap:LettersOfCreditOutstandingAmount


Letters
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value16161819192023242424242525252526262831313131312921212021191919
Percentage of LettersOfCreditOutstandingAmount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent


Liabilities
Period End2021-03-312020-12-312018-09-302017-12-31
Value32302224
Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0100.0100.0

us-gaap:LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent us-gaap:IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperations

hmhc:HMHBooksAndMediaSegment


Liabilities
Period End2021-03-312020-12-31
Value3230
Percentage of LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent100.0100.0

us-gaap:LineOfCredit us-gaap:CreditFacility, us-gaap:SubsequentEventType

us-gaap:LineOfCredit

us-gaap:RevolvingCreditFacility, us-gaap:SubsequentEvent


Line
Period End2020-08-06
Value0.0
Percentage of LineOfCredit0.0

us-gaap:LongTermDebtFairValue us-gaap:DebtInstrument

us-gaap:LongTermDebtFairValue

hmhc:TermLoan


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value20340331314332314360735717722710722714699710742733709732766759754770782793178242243245246247
Percentage of LongTermDebtFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LongTermDebtFairValue us-gaap:LongtermDebtType

us-gaap:SecuredDebt


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value314319304286283261301
Percentage of LongTermDebtFairValue1504.793.991.891.185.283.183.6

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths


Long
Period End2020-12-31
Value19
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive


Long
Period End2020-12-31
Value306
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour


Long
Period End2020-12-31
Value304
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree


Long
Period End2020-12-31
Value19
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo


Long
Period End2020-12-31
Value19
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo100.0

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent


Operating
Period End2020-12-312019-12-31
Value12.5612.46
Percentage of OperatingLeaseWeightedAverageDiscountRatePercent100.0100.0

us-gaap:OperatingLossCarryforwards us-gaap:StatementGeographical, us-gaap:IncomeTaxAuthority

us-gaap:OperatingLossCarryforwards

country:CA, us-gaap:StateAndLocalJurisdiction


Operating
Period End2020-12-312019-12-312018-12-31
Value0.71.61.8
Percentage of OperatingLossCarryforwards100.0100.0100.0

country:IE, us-gaap:ForeignCountry


Operating
Period End2020-12-312019-12-312018-12-31
Value1421723
Percentage of OperatingLossCarryforwards20371.41106.21311.1

us-gaap:OtherIntangibleAssetsNet

us-gaap:OtherIntangibleAssetsNet


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value381391428440451462474486499511520535578593610626645664685848868888912939966775801830858886919
Percentage of OtherIntangibleAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent

us-gaap:OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value15151613131415131313141819192020202122222223232425252621222323
Percentage of OtherPostretirementDefinedBenefitPlanLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrent

us-gaap:PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrent


Pension
Period End2021-06-302021-03-312020-12-312019-12-31
Value1555000.01555000.01555000.01571000.0
Percentage of PensionAndOtherPostretirementAndPostemploymentBenefitPlansLiabilitiesCurrent100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1555000.01571000.01512000.01618000.01928000.01910000.02037000.02141000.0
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent


Pension
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value1816152124252826
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForLetterOfCreditFacilities

us-gaap:PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForLetterOfCreditFacilities


Pledged
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1100000.01100000.01100000.0700000.0700000.0700000.0700000.0200000.0200000.0100000.0100000.0100000.0100000.0100000.0100000.02400000.02400000.02400000.02400000.02500000.02500000.02500000.02500000.02400000.02400000.02400000.02400000.02400000.02400000.0
Percentage of PledgedFinancialInstrumentsNotSeparatelyReportedSecuritiesForLetterOfCreditFacilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount

us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount


Reporting
Period End2020-09-302020-03-312019-10-01
Value18.012.018.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount100.0100.0100.0

us-gaap:RestructuringReserve us-gaap:RestructuringCostAndReserve, us-gaap:RestructuringPlan

us-gaap:RestructuringReserve

hmhc:SeveranceAndTerminationBenefits, hmhc:TwoThousandAndNineteenRestructuringPlan


Restructuring
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value0.0250.1520.2792.6064.0686.76911
Percentage of RestructuringReserve100.0100.0100.0100.0100.0100.0100.0

hmhc:SeveranceAndTerminationBenefits, hmhc:TwoThousandAndTwentyRestructuringPlan


Restructuring
Period End2021-06-302021-03-312020-12-312020-09-30
Value5.027111932
Percentage of RestructuringReserve20108.07422.46921.51239.3

us-gaap:EmployeeSeverance, hmhc:TwoThousandAndNineteenRestructuringPlan


Restructuring
Period End2020-12-312019-12-312019-09-302018-12-31
Value0.7580.7581.3121.42
Percentage of RestructuringReserve271.76.50.00.0

us-gaap:RestructuringReserve us-gaap:RestructuringPlan

hmhc:TwoThousandAndNineteenRestructuringPlan


Restructuring
Period End2020-12-312020-06-302020-03-312019-12-312019-09-302018-12-31
Value0.7584.0686.769111.3121.69
Percentage of RestructuringReserve271.7100.0100.0100.00.00.0

us-gaap:RestructuringReserveCurrent

us-gaap:RestructuringReserveCurrent


Restructuring
Period End2020-12-312020-06-302020-03-312019-12-312018-12-31
Value194.17.1126.02
Percentage of RestructuringReserveCurrent100.0100.0100.0100.0100.0

us-gaap:RestructuringReserveCurrent us-gaap:RestructuringPlan

hmhc:TwoThousandAndNineteenRestructuringPlan


Restructuring
Period End2020-09-302019-12-31
Value3412
Percentage of RestructuringReserveCurrent0.099.9

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue us-gaap:AwardType

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue

us-gaap:RestrictedStockUnitsRSU


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-31
Value5.348.039.1613.3718.2619.9317.2214.11
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice


Share
Period End2020-12-31
Value13.65
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value0.00.10.50.00.06381530.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue0.0100.0100.00.00.0100.0100.0100.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue


Share
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value0.00.10.00.00.062
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue0.0100.00.00.00.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice


Share
Period End2020-12-31
Value12.97
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice100.0

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1


Sharebased
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-31
Value0.00.00.00.00.03935140.0
Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue10.00.00.00.00.0100.0100.0100.00.0

us-gaap:SupplementalUnemploymentBenefitsSeveranceBenefits

us-gaap:SupplementalUnemploymentBenefitsSeveranceBenefits


Supplemental
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value5.0521119344.097.087121.3122.0281.7176.026.8616.767.2196.9269.475155.6068.8637.1455.7974.7244.8945.0264.6775.8765.9285.6485.9347.2328.184
Percentage of SupplementalUnemploymentBenefitsSeveranceBenefits100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TaxCreditCarryforwardAmount us-gaap:IncomeTaxAuthority

us-gaap:TaxCreditCarryforwardAmount

us-gaap:DomesticCountry


Tax
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value1058858611602377127127
Percentage of TaxCreditCarryforwardAmount100.0100.0100.0100.0100.0100.0100.0

us-gaap:ForeignCountry


Tax
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-31
Value7.38.08.41112111.5
Percentage of TaxCreditCarryforwardAmount0.70.91.42.03.29.01.2

us-gaap:StateAndLocalJurisdiction


Tax
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value1419117412341189775345
Percentage of TaxCreditCarryforwardAmount134.1136.8201.9197.5205.4269.7

us-gaap:TaxCreditCarryforwardAmount us-gaap:IncomeTaxAuthority, us-gaap:TaxCreditCarryforward

us-gaap:DomesticCountry, hmhc:ExpireBetweenTwoThousandThirtyFourAndTwoThousandThirtySeven


Tax
Period End2020-12-312019-12-31
Value612609
Percentage of TaxCreditCarryforwardAmount57.871.0

us-gaap:DomesticCountry, hmhc:PostTaxReform


Tax
Period End2020-12-31
Value446
Percentage of TaxCreditCarryforwardAmount42.2

us-gaap:TaxCreditCarryforwardAmount us-gaap:StatementGeographical, us-gaap:TaxCreditCarryforward

country:PR, hmhc:AlternativeMinimumTaxCreditCarryforward


Tax
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2.82.82.72.82.7
Percentage of TaxCreditCarryforwardAmount0.30.30.40.50.7

us-gaap:TaxCreditCarryforwardAmount us-gaap:TaxCreditCarryforward

us-gaap:Research


Tax
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4.24.24.24.21.7
Percentage of TaxCreditCarryforwardAmount0.40.50.70.70.5

us-gaap:ValuationAllowancesAndReservesBalance

us-gaap:ValuationAllowancesAndReservesBalance


Valuation
Period End2020-12-312019-12-31
Value96119
Percentage of ValuationAllowancesAndReservesBalance100.0100.0

us-gaap:ValuationAllowancesAndReservesBalance us-gaap:ValuationAllowancesAndReservesType

hmhc:AllowanceForSalesReturn


Valuation
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value141618201823
Percentage of ValuationAllowancesAndReservesBalance15.113.90.00.00.00.0

hmhc:Royalties


Valuation
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value96119117103857055412612
Percentage of ValuationAllowancesAndReservesBalance100.0100.00.00.00.00.00.00.00.00.0

us-gaap:AllowanceForCreditLoss


Valuation
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value3.9893.0152.1732.5083.4638.323
Percentage of ValuationAllowancesAndReservesBalance4.12.50.00.00.00.0

us-gaap:Royalty


Valuation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value7.57.47.3132128123119
Percentage of ValuationAllowancesAndReservesBalance0.00.07.50.00.00.0100.0

us-gaap:ValuationAllowanceOfDeferredTaxAssets


Valuation
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-312014-12-312013-12-312012-12-312011-12-31
Value662583562571759668550527512822
Percentage of ValuationAllowancesAndReservesBalance685.2487.50.00.00.00.00.00.00.00.0

Line plots across dimensions of each concept


us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities
(None,)
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amountus-gaap: Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities
TTM Greenblatt ROC
_
(None,)
T T M  Greenblatt  R O C_
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
('us-gaap:OperatingSegments', None)
Revenue From Contract With Customer Excluding Assessed Taxus-gaap: Consolidation Items, us-gaap: Statement Business Segments
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems, us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
('us-gaap:OperatingSegments', None, 'hmhc:EducationalServices')
Revenue From Contract With Customer Excluding Assessed Taxus-gaap: Consolidation Items, us-gaap: Product Or Service, us-gaap: Statement Business Segments
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ConsolidationItems, us-gaap:ProductOrService
('us-gaap:OperatingSegments', None)
Revenue From Contract With Customer Excluding Assessed Taxus-gaap: Consolidation Items, us-gaap: Product Or Service
us-gaap:Assets
us-gaap:StatementBusinessSegments
(None,)
Assetsus-gaap: Statement Business Segments
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
Stockholders Equityus-gaap: Statement Equity Components
us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
(None,)
Finite Lived Intangible Assets Netus-gaap: Finite Lived Intangible Assets By Major Class
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
Stockholders Equityus-gaap: Statement Equity Components