HCC


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:AwardType, us-gaap:PlanName
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareDiluted

us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:AwardType, us-gaap:PlanName

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostsAndExpenses

us-gaap:GrossProfit

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeTaxExpenseBenefit

us-gaap:InterestIncomeExpenseNonoperatingNet

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:OperatingIncomeLoss

us-gaap:OtherIncome

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
us-gaap:MajorCustomers, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType
us-gaap:ProductOrService

us-gaap:SellingGeneralAndAdministrativeExpense

us-gaap:Assets

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:PropertyPlantAndEquipmentByType
us-gaap:PropertyPlantAndEquipmentGross

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:OtherAssetsNoncurrent

us-gaap:AccountsPayableCurrent

us-gaap:AccruedLiabilitiesCurrent

us-gaap:LiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent

us-gaap:LongTermDebt

us-gaap:LongTermDebtNoncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapital

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:TreasuryStockValue
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodValueNewIssues
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DepreciationDepletionAndAmortization

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInInventories

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment
us-gaap:ConsolidationItems
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:PaymentsOfDividends

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:ProceedsFromSaleOfShortTermInvestments

hcc:BusinessInterruption

hcc:IdleMine

hcc:IncomeTaxReconciliationDeductibleBenefitExpenseDiscreteTaxItems

hcc:NetIncomeLossbeforeInterestTaxesDepreciationandAmortization
us-gaap:StatementEquityComponents
us-gaap:AdjustmentsToAdditionalPaidInCapitalOther

us-gaap:AmortizationOfFinancingCostsAndDiscounts

us-gaap:AssetRetirementObligationAccretionExpense
us-gaap:MajorCustomers, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType
us-gaap:ConcentrationRiskPercentage1

us-gaap:DerivativeGainLossOnDerivativeNet
us-gaap:StatementEquityComponents
us-gaap:DividendsCommonStockCash

us-gaap:FinanceLeaseInterestExpense

us-gaap:FinanceLeasePrincipalPayments

us-gaap:FinanceLeaseRightOfUseAssetAmortization

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationNondeductibleExpenseDepletion

us-gaap:IncomeTaxReconciliationTaxContingenciesStateAndLocal

us-gaap:IncomeTaxReconciliationTaxCredits

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets
us-gaap:AwardType, us-gaap:PlanName
us-gaap:IncrementalCommonSharesAttributableToContingentlyIssuableShares

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
us-gaap:AwardType, us-gaap:PlanName
us-gaap:PlanName

us-gaap:LeaseCost

us-gaap:LitigationSettlementAmountAwardedFromOtherParty

us-gaap:OperatingLeaseCost

us-gaap:OtherCostOfOperatingRevenue

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:PaymentsToAcquireMiningAssets

us-gaap:PaymentsToAcquireOtherPropertyPlantAndEquipment

us-gaap:PaymentsToAcquireShortTermInvestments

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment
us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty
us-gaap:RelatedPartyTransactionAmountsOfTransaction

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability

us-gaap:RoyaltyExpense
us-gaap:ShareRepurchaseProgram
us-gaap:TreasuryStockValueAcquiredCostMethod

hcc:AccruedFreightCurrent

hcc:AccruedOperatingExpensesCurrent

hcc:AssetsHeldInTrustSelfInsuranceReserveNoncurrent

hcc:DeferredMovingCostsCurrent

hcc:FinanceLeaseExcludingLeasesNotYetCommencedLiability

hcc:FinanceLeaseLiabilityToBePaidAfterYearFour

hcc:InventoryRawMaterialsPurchasedPartsSuppliesandOtherNetofReserve

hcc:LesseeFinanceLeaseLeaseNotYetCommenced
us-gaap:IncomeTaxAuthority
hcc:OperatingLossCarryforwardsIndefiniteLived

hcc:PrepaidDepositsCurrent

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccruedRoyaltiesCurrent

us-gaap:AssetRetirementObligation

us-gaap:AssetRetirementObligationCurrent

us-gaap:AssetRetirementObligationsNoncurrent
us-gaap:CreditFacility
us-gaap:DebtInstrumentCarryingAmount
us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentFairValue

us-gaap:DebtInstrumentUnamortizedDiscount
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet

us-gaap:DebtIssuanceCostsLineOfCreditArrangementsNet
us-gaap:CreditFacility, us-gaap:LineOfCreditFacility

us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance

us-gaap:DeferredTaxLiabilitiesDeferredExpenseCapitalizedInventoryCosts

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesPrepaidExpenses

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:DerivativeLiabilities
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency
us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation
us-gaap:DerivativeLiabilitiesCurrent

us-gaap:EmployeeRelatedLiabilitiesCurrent
us-gaap:AwardType, us-gaap:PlanName, us-gaap:Vesting
us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
us-gaap:PlanName

us-gaap:EnergyRelatedInventoryCoal

us-gaap:FinanceLeaseLiability

us-gaap:FinanceLeaseLiabilityCurrent

us-gaap:FinanceLeaseLiabilityNoncurrent

us-gaap:FinanceLeaseLiabilityPaymentsDue

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo

us-gaap:FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount

us-gaap:FinanceLeaseRightOfUseAsset

us-gaap:FinanceLeaseRightOfUseAssetAccumulatedAmortization

us-gaap:FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization

us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent
us-gaap:GuaranteeObligationsByNature
us-gaap:GuaranteeObligationsMaximumExposure

us-gaap:HeldToMaturitySecuritiesCurrent
us-gaap:FinancialInstrument

us-gaap:InterestPayableCurrent

us-gaap:LettersOfCreditOutstandingAmount
us-gaap:CreditFacility, us-gaap:LineOfCreditFacility, us-gaap:LongtermDebtType
us-gaap:CreditFacility, us-gaap:LineOfCreditFacility
us-gaap:LineOfCredit
us-gaap:CreditFacility, us-gaap:LineOfCreditFacility, us-gaap:LongtermDebtType
us-gaap:CreditFacility, us-gaap:LineOfCreditFacility
us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity
us-gaap:DebtInstrument, us-gaap:LongtermDebtType
us-gaap:DebtInstrument, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:LongtermDebtType
us-gaap:LongTermDebtFairValue

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive
us-gaap:LongtermDebtType

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour
us-gaap:CreditFacility
us-gaap:CreditFacility
us-gaap:LongtermDebtWeightedAverageInterestRate
us-gaap:LongtermDebtType

us-gaap:MineralPropertiesAccumulatedDepletion

us-gaap:MineralPropertiesGross

us-gaap:MineralPropertiesNet
us-gaap:IncomeTaxAuthority
us-gaap:OperatingLossCarryforwards

us-gaap:OtherAssetsMiscellaneousNoncurrent

us-gaap:OtherPrepaidExpenseCurrent

us-gaap:OtherReceivablesNetCurrent

us-gaap:OtherSundryLiabilitiesNoncurrent

us-gaap:PrepaidExpenseCurrent

us-gaap:PrepaidInsurance

us-gaap:PrepaidMineralRoyaltiesNoncurrent

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization

us-gaap:SelfInsuranceReserve

us-gaap:SelfInsuranceReserveCurrent

us-gaap:SelfInsuranceReserveNoncurrent
us-gaap:TaxCreditCarryforward
us-gaap:TaxCreditCarryforwardAmount

Plots across concepts


IncomeStatement
Income Loss From Continuing Operations 
Before Income Taxes Extraordinary Items Noncontrolling Interest
Expenses
Income Tax Expense Benefit
Balance Sheet
Liabilities Current
Assets
Inventory Net
Current Assets
Prepaid Expense And Other Assets Current
NonCurrent Assets
Other Assets Noncurrent
Liabilities
Dividends Payable Current And Noncurrent
Current Liabilities
Other Liabilities Current
Noncurrent Liabilities
Other Liabilities Noncurrent
Stockholders Equity
Common Stock Value
CashFlow
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInOperatingActivities
Increase Decrease In Inventories
NetCashProvidedByUsedInInvestingActivities
Net Cash Provided By Used In Investing Activities
NetCashProvidedByUsedInFinancingActivities
Net Cash Provided By Used In Financing Activities
Shares
Weighted Average Number Of Diluted Shares Outstanding

Tables

  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:CommonStockValue ██▃▁▁▁▁▁▁▁▁▃▃▃▃0.5360.5360.5340.5330.5330.5330.5330.5330.5330.5330.5330.5340.5340.5340.534NANANA0.533NANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁51.44951.274NA51.35651.28851.273NA51.48251.68151.63NA52.70853.07953.152NA52.77752.72152.681NANANA
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁51.44951.274NA51.1951.18751.106NA51.34851.55351.511NA52.70753.05353.149NA52.77752.72152.681NANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AwardType,us-gaap:PlanName hcc:RestrictedStockUnitsRSUsPerformanceAndMarketBasedVestingConditions,hcc:A2017EquityPlanNA0.523479NANANA0.45413NANANA0.280492NANANANANANANANANANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AwardType,us-gaap:PlanName hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions,hcc:A2016EquityPlanNA0.027431NANANA0.073429NANANA0.124307NANANANANANANANANANANA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AwardType,us-gaap:PlanName hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions,hcc:A2017EquityPlanNA0.319863NANANA0.248294NANANA0.157124NANANANANANANANANANANA
us-gaap:EarningsPerShareBasic ▂▁▁▁▁▂▂▂▄▄█▂▃▅▃▄-0.09-0.42-0.66-0.28-0.180.420.410.882.432.147.131.01.723.361.82999999999999922.27NANANANANA
us-gaap:EarningsPerShareDiluted ▂▁▁▁▁▂▂▂▄▄█▂▃▅▃▄-0.09-0.42-0.66-0.28-0.180.420.410.872.432.147.111.01.723.361.82999999999999922.27NANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:AllocatedShareBasedCompensationExpense 4.1NANANANANANANANA0.5NA0.60.6NANANANANANANANA
us-gaap:CostOfGoodsAndServicesSold ▄▄▇▄▃▄▄▇█▆▆▅▆▇▃▇▅▁152.765154.35191.509151.37130.777151.514142.707190.221205.188182.628180.238167.188178.543190.676136.67189.564160.152106.144NANANA
us-gaap:CostsAndExpenses ▇▅█▄▃▄▃▇█▆▅▅▆▇▃▇▅▁230.27202.685250.031194.591169.032196.223180.831232.907249.668221.511203.142210.585221.459234.534173.301229.185200.094143.111NANANA
us-gaap:GrossProfit NANA9.27521.6325.28267.64555.71389.702184.406187.917191.77699.412136.674223.32897.67115.406195.423139.641NANANA
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▂▂▁▂▂▃▃▄▇▇▇▄▅█▄▅▇▆-11.3072.277-44.519-22.586-13.58624.78617.52852.621158.537138.431148.37652.59191.312178.69461.44582.13162.634110.245NANANA
us-gaap:IncomeTaxExpenseBenefit ▇█▇▇▇▇▇▇██▁▇▇▇▆▆█▇-6.62623.632-10.808-8.152-4.4253.241-3.2227.59933.05627.984-225.8140.00.00.0-35.711-37.58732.7691.937NANANA
us-gaap:InterestIncomeExpenseNonoperatingNet ▂▂▂▃▂▃▄▃▃▂▂▁▁▂▅███-8.477-8.693-8.463-8.059-8.255-7.533-6.542-7.25-6.951-8.592-8.842-10.128-9.784-8.56-5.057-0.64-0.642-0.608NANANA
us-gaap:NetIncomeLoss ▂▁▁▂▂▂▂▃▄▄█▃▃▅▃▄▄▄▂▁▁-4.681-21.355-33.711-14.434-9.16121.54520.75145.022125.481110.447374.1952.59191.312178.69497.156119.717129.865108.30834.032-33.642-50.063
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▁▁▁▁▁▂▂▂▄▃█▂▃-4.681-21.355-33.711-14.434-9.16121.54520.7545.022125.481110.447374.1952.59191.312NANANANANANANANA
us-gaap:OperatingIncomeLoss ▂▃▁▂▂▃▃▄▇▇▇▄▅█▄▅▇▆▃▁▁-2.8311.079-37.778-14.527-5.33130.49724.07154.599147.945156.779157.21862.719101.096187.25466.50282.77163.276110.85334.633-32.948-49.629
us-gaap:OtherIncome NANA1.7220.00.01.8220.05.27217.5430.00.00.00.0NANANANANANANANA
us-gaap:OtherNonoperatingIncomeExpense █▁0.0-0.109NANA0.01.822NANANANANANANANANANANANANANANA
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax ▄▄▄▃▃▄▄▅█▇▇▅▆█▅▆▇▅▃▁▂227.44213.764212.253180.064163.701226.72204.901287.506397.613378.29360.36273.304322.555421.788239.803311.955363.37253.964153.26952.89191.474
us-gaap:SellingGeneralAndAdministrativeExpense ▆▃▃▄▄▄▃▅▆▄▃▃█▄█▄▄▁11.1157.6377.7748.1928.4578.4567.9649.36210.7838.9057.577.35713.4658.23413.389.2438.665.17NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:Assets ▇▇▇▇▇█▇▇▆▇▇▃▂▆▁1347.0781379.9911393.9361391.0131397.1891439.1741344.2641349.5821290.4781400.0011395.041100.1181029.7831301.61993.315NANANA947.631NANA
us-gaap:Liabilities ▄▆▅▃▃▄▁▂▁▁▆█▇▇▁648.924679.688668.695631.302622.226654.052578.682603.645577.82580.937682.428734.424714.913716.7580.292NANANA194.664NANA
us-gaap:LiabilitiesAndStockholdersEquity ▇▇▇▇▇█▇▇▆▇▇▃▂▆▁1347.0781379.9911393.9361391.0131397.1891439.1741344.2641349.5821290.4781400.0011395.041100.1181029.7831301.61993.315NANANA947.631NANA
us-gaap:StockholdersEquity ▆▆▇▇▇█▇▇▇█▇▂▁▅▂698.154700.303725.241759.711774.963785.122765.582745.937712.658819.064712.612365.694314.87584.91413.023NANANA752.967NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:AssetsCurrent ▅▆▆▆▇█▅▅▄▆▆▃▂█▁452.06477.126467.483502.018519.32564.531444.046462.858400.776466.006469.169367.551293.004575.097268.869NANANA290.773NANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▇▆▅▅▆▆▅▅▃▄▅▃▁█▁266.876221.947211.916216.413220.663256.743193.383208.673119.318154.912205.577130.15555.087322.02435.47NANANA150.045NANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents ▇▆▅▆▆▆▅▅▃▄▅▄▂█▁▆▄▁▄266.876221.947211.916216.413220.663256.743193.383209.503120.145155.742206.405130.98255.913322.85236.264235.407157.14616.066152.656NANA
us-gaap:AccountsReceivableNetCurrent ▁▂▂▂▂▅▃▄▇█▅▄▅▆▄65.15876.1283.29881.41777.009131.52699.471109.245160.834182.728138.399113.75129.946152.325117.746NANANA65.896NANA
us-gaap:InventoryNet ▃▇▆██▅▄▃▂▂▁▂▂▁▁76.964135.696118.713155.667153.905117.56397.90181.91869.23470.35656.71966.77159.44651.28254.294NANANA39.42NANA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent NANA39.91NANANA23.844NANANA27.932NANANA29.376NANANA12.01NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType hcc:BuildingAndLeaseholdImprovementsNANA77.556NANANA74.342NANANA71.561NANANA82.836NANANA64.814NANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType hcc:MineDevelopmentAndInfrastructureCostsNANA29.893NANANA13.315NANANA3.567NANANA0.308NANANA0.0NANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:ConstructionInProgressNANA82.367NANANA42.106NANANA46.814NANANA39.671NANANA26.873NANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:LandNANA71.886NANANA72.267NANANA72.139NANANA72.882NANANA72.882NANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:LandImprovementsNANA18.024NANANA18.026NANANA18.083NANANA11.444NANANA11.444NANA
 us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:MachineryAndEquipmentNANA679.393NANANA614.687NANANA512.594NANANA441.353NANANA366.317NANA
us-gaap:DeferredTaxAssetsLiabilitiesNet NANA174.372NANANA154.297NANANA222.78NANANANANANANANANANA
us-gaap:OtherAssetsNoncurrent ▁▂▃▃▃▅▆▆▇██▇█▇▆11.94412.99714.11815.14515.34317.56818.24219.33719.7121.67521.03920.84121.31919.85318.442NANANA16.668NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:AccountsPayableCurrent ▅█▇▅▆▆▄▅▃▄▂▃▃▂▁48.03265.33659.1150.00255.80554.6246.43650.82136.46742.22233.58837.07740.12430.99628.076NANANA6.043NANA
us-gaap:AccruedLiabilitiesCurrent ▁▄█▅▃▄▄█▅▅▇█▄▅▄46.64362.90186.10867.51560.34363.47665.75584.41770.74269.45682.34287.12366.47569.33266.704NANANA47.339NANA
us-gaap:LiabilitiesCurrent ▄▇█▅▄▄▃▆▂▂▃▄▂▂▁130.67160.963170.318139.277131.147132.726128.952150.179121.257121.5124.432134.751115.693120.035108.22NANANA64.636NANA
us-gaap:OtherLiabilitiesCurrent ▅▄▂▄▃▂▁▂▂▄▂▄▃█▃11.1469.1076.3619.8867.2736.6083.9925.3275.3899.8224.9679.0396.83716.7126.903NANANA5.307NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:LongTermDebt ▃▃▃▃▃▅▁▁▁▁████▁380.292380.098379.908379.722379.541409.363339.189339.02338.854338.699468.991467.591468.117468.54345.913NANANA6.574NANA
us-gaap:LongTermDebtNoncurrent ▃▃▃▃▃▅▁▁▁▁████▁380.292380.098379.908379.722379.541409.363339.189339.02338.854338.699468.231466.079465.86465.545342.948NANANA3.725NANA
us-gaap:OtherLiabilitiesNoncurrent ▅▅▁▅▅▅▁▄▄█▂▅▅▅▁37.17837.2192.25832.27631.82131.551.19726.35526.18761.0945.5134.16635.07833.9932.562NANANA1.153NANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:StockholdersEquity ▆▆▇▇▇█▇▇▇█▇▂▁▅▂698.154700.303725.241759.711774.963785.122765.582745.937712.658819.064712.612365.694314.87584.91413.023NANANA752.967NANA
us-gaap:CommonStockValue ██▃▁▁▁▁▁▁▁▁▃▃▃▃0.5360.5360.5340.5330.5330.5330.5330.5330.5330.5330.5330.5340.5340.5340.534NANANA0.533NANA
us-gaap:AdditionalPaidInCapital ▂▂▂▂▂▁▁▁▁▁▁▁▁██253.922248.774249.746247.907246.126244.525243.932242.458241.02240.408239.827239.027238.162325.871329.993NANANA802.107NANA
us-gaap:RetainedEarningsAccumulatedDeficit ▆▆▇▇▇█▇▇▇█▇▂▁▃▁494.272501.569525.537561.847578.88590.64571.693553.522511.105618.123510.282138.23388.274258.50582.496NANANA-49.673NANA
us-gaap:TreasuryStockValue ████████▆▆▆▁▁50.57650.57650.57650.57650.57650.57650.57650.57640.040.038.0312.112.1NA0.0NANANANANANA
 us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents us-gaap:CommonStock▁█0.00.002NANANANANANANANANANANANANANANANANANANA
 us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents us-gaap:AdditionalPaidInCapital█▃▃▃▃▃▃▃▃▂▂▂▇▁5.4151.5671.841.7811.8621.6051.4741.4381.3271.1080.8070.9194.4810.198NANANANANANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▂▁▁▁▁▁▅█▅▅▄▅▇▃▄▆▂68.67845.22230.47329.16731.96421.02224.549150.427231.43126.408130.797102.342132.519193.73891.446116.109161.40465.553NANANA
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▆▄▄▄▆▃▁▄▄▄▅▃▅▄▃▇█-15.129-21.792-29.106-27.831-31.033-20.219-33.903-42.455-28.116-29.739-28.405-23.805-32.877-22.542-29.954-34.408-16.885-11.378NANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▆▆▆▆▆▇▆▆▃▄▆▆▁█▃▆▆▄-8.62-13.399-5.864-5.586-37.01162.557-6.766-18.614-238.911-147.332-26.969-3.468-366.581115.392-260.635-3.44-3.439-190.765NANANA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect ▅▅▄▄▄▅▄▆▄▄▅▅▁█▂▅▆▃44.92910.031-4.497-4.25-36.0863.36-16.1289.358-35.597-50.66375.42375.069-266.939286.588-199.14378.261141.08-136.59NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:DeferredIncomeTaxExpenseBenefit ▇█▇▇▇▇▇▇██▁▇▇▇-6.62623.632-10.807-8.114-4.433.276-0.077.59932.9727.984-223.0380.00.00.0NANANANANANANA
us-gaap:DepreciationDepletionAndAmortization █▆█▅▃▅▃▄▄▃▄▄▃▄▂▃▂▁40.15132.90339.27927.96522.15628.69223.67825.74125.67822.23325.45926.07121.12724.55217.78823.39319.6514.582NANANA
us-gaap:IncreaseDecreaseInAccountsPayable ▁▆▆▃▅█▄▇▄▇▃▄▇▅▅▅▄▇-17.2774.9644.192-6.211.76515.614-5.3412.93-4.82110.64-6.566-3.84312.5382.9313.8382.772-2.45910.237NANANA
us-gaap:IncreaseDecreaseInAccountsReceivable ▄▄▅▅▁▇▄▁▃█▇▄▃▇▄▇▅▇-10.961-7.1781.8814.408-54.51732.055-9.774-51.589-21.89444.32924.649-16.196-22.37934.579-10.79535.99-3.62930.284NANANA
us-gaap:IncreaseDecreaseInInventories ▁▇▃▅█▇▆▆▅▆▅▆▆▅▇▂▆█-49.15516.107-30.422-1.70728.26817.32610.2039.655-0.1910.823-9.2555.6777.174-1.78417.804-37.0034.33928.592NANANA
us-gaap:NetCashProvidedByUsedInOperatingActivities ▃▂▁▁▁▁▁▅█▅▅▄▅▇▃▄▆▂68.67845.22230.47329.16731.96421.02224.549150.427231.43126.408130.797102.342132.519193.73891.446116.109161.40465.553NANANA
us-gaap:NetIncomeLoss ▂▁▁▂▂▂▂▃▄▄█▃▃▅▃▄▄▄▂▁▁-4.681-21.355-33.711-14.434-9.16121.54520.75145.022125.481110.447374.1952.59191.312178.69497.156119.717129.865108.30834.032-33.642-50.063
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings▁▁▁▁▁▂▂▂▄▃█▂▃-4.681-21.355-33.711-14.434-9.16121.54520.7545.022125.481110.447374.1952.59191.312NANANANANANANANA
us-gaap:ShareBasedCompensation █▃▃▃▄▃▃▃▃▃▂▂▇▁▅▁▂▁5.5441.6961.9681.911.9911.7331.6021.5691.4551.1940.8070.9194.4810.1983.0260.2330.9220.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities ▇▆▄▄▄▆▃▁▄▄▄▅▃▅▄▃▇█-15.129-21.792-29.106-27.831-31.033-20.219-33.903-42.455-28.116-29.739-28.405-23.805-32.877-22.542-29.954-34.408-16.885-11.378NANANA
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment ▂▁▃▅▆▅▆▆▆▅▅▅█▅▇█▃▂14.1729.47915.42923.30525.97922.77528.91226.26627.70524.39522.04124.1632.87722.54229.95434.40816.88511.378NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▆▆▆▆▆▇▆▆▃▄▆▆▁█▃▆▆▄-8.62-13.399-5.864-5.586-37.01162.557-6.766-18.614-238.911-147.332-26.969-3.468-366.581115.392-260.635-3.44-3.439-190.765NANANA
us-gaap:PaymentsOfDividends ▁▁▁▁▁▁▁▁▄▁▁▁▅▁█▁▁▃2.6162.6132.5992.5992.5992.5982.582.604232.6042.6062.6532.632352.6652.685601.5522.6772.673190.0NANANA
  2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue


Common
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value536000.0536000.0534000.0533000.0533000.0533000.0533000.0533000.0533000.0533000.0533000.0534000.0534000.0534000.0534000.0533000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.10.00.10.1

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value5151515151515151525353525252
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


Weighted
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-31
Value5151515151515151525353525252
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AwardType, us-gaap:PlanName

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

hcc:RestrictedStockUnitsRSUsPerformanceAndMarketBasedVestingConditions, hcc:A2017EquityPlan


Antidilutive
Period End2021-03-312020-03-312019-03-31
Value523480.0454130.0280490.0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0100.0

hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions, hcc:A2016EquityPlan


Antidilutive
Period End2021-03-312020-03-312019-03-31
Value27431.073429.0124310.0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount5.216.244.3

hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions, hcc:A2017EquityPlan


Antidilutive
Period End2021-03-312020-03-312019-03-31
Value319860.0248290.0157120.0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount61.154.756.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic


Earnings
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-0.09-0.42-0.66-0.28-0.180.420.410.882.432.147.131.01.723.361.832.27
Percentage of EarningsPerShareBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted


Earnings
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-0.09-0.42-0.66-0.28-0.180.420.410.872.432.147.111.01.723.361.832.27
Percentage of EarningsPerShareDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Allocated Share Based Compensation Expense

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:AllocatedShareBasedCompensationExpense


Allocated
Period End2021-06-302019-03-312018-09-302018-06-30
Value4100000.0500000.0600000.0600000.0
Percentage of AllocatedShareBasedCompensationExpense100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.80.10.20.2

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:AwardType, us-gaap:PlanName

us-gaap:RestrictedStockUnitsRSU, hcc:A2017EquityPlanApril2020Award


Allocated
Period End2020-09-302020-06-30
Value87800.0639000.0
Percentage of AllocatedShareBasedCompensationExpense0.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.00.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RestrictedStockUnitsRSU hcc:A2017EquityPlanApril2020Award0.00.0

us-gaap:RestrictedStockUnitsRSU, hcc:A2017EquityPlanFebruary2020Award


Allocated
Period End2020-09-302020-06-30
Value900000.01000000.0
Percentage of AllocatedShareBasedCompensationExpense0.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.50.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RestrictedStockUnitsRSU hcc:A2017EquityPlanFebruary2020Award0.00.0

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold


Cost
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value152154191151130151142190205182180167178190136189160106
Percentage of CostOfGoodsAndServicesSold100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax67.272.290.284.179.966.869.666.251.648.350.061.255.445.257.060.844.141.8

Costs And Expenses

us-gaap:CostsAndExpenses

us-gaap:CostsAndExpenses


Costs
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
Value230202250194169196180232249221203210221234173229200143
Percentage of CostsAndExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax101.294.8117.8108.1103.386.588.381.062.858.656.477.168.755.672.373.555.156.4

Gross Profit

us-gaap:GrossProfit

us-gaap:GrossProfit


Gross
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value9.27521256755891841871919913622397115195139
Percentage of GrossProfit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.412.015.429.827.231.246.449.753.236.442.452.940.737.053.855.0

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

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-11.3072.277-44.519-22.586-13.58624175215813814852911786182162110
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-5.01.1-21.0-12.5-8.310.98.618.339.936.641.219.228.342.425.626.344.843.4

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


Income
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-6.62623-10.808-8.152-4.4253.241-3.2227.5993327-225.8140.00.00.0-35.711-37.587321.937
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.911.1-5.1-4.5-2.71.4-1.62.68.37.4-62.70.00.00.0-14.9-12.09.00.8

Interest Income Expense Nonoperating Net

us-gaap:InterestIncomeExpenseNonoperatingNet

us-gaap:InterestIncomeExpenseNonoperatingNet


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
Value-8477000.0-8693000.0-8463000.0-8059000.0-8255000.0-7533000.0-6542000.0-7250000.0-6951000.0-8592000.0-8842000.0-10128000.0-9784000.0-8560000.0-5057000.0-640000.0-642000.0-608000.0
Percentage of InterestIncomeExpenseNonoperatingNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.7-4.1-4.0-4.5-5.0-3.3-3.2-2.5-1.7-2.3-2.5-3.7-3.0-2.0-2.1-0.2-0.2-0.2

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-4.681-21.355-33.711-14.434-9.16121204512511037452911789711912910834-33.642-50.063
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.1-10.0-15.9-8.0-5.69.510.115.731.629.2103.819.228.342.440.538.435.742.622.2-63.6-54.7

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-4.681-21.355-33.711-14.434-9.1612120451251103745291
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.1-10.0-15.9-8.0-5.69.510.115.731.629.2103.819.228.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.0

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-2.8311-37.778-14.527-5.33130245414715615762101187668216311034-32.948-49.629
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-1.25.2-17.8-8.1-3.313.511.719.037.241.443.622.931.344.427.726.544.943.622.6-62.3-54.3

Other Income

us-gaap:OtherIncome

us-gaap:OtherIncome


Other
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value1.7220.00.01.8220.05.272170.00.00.00.0
Percentage of OtherIncome100.00.00.0100.00.0100.0100.00.00.00.00.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.80.00.00.80.01.84.40.00.00.00.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


Other
Period End2021-06-302021-03-312020-06-302020-03-31
Value0-109000.001822000.0
Percentage of OtherNonoperatingIncomeExpense0.0100.00.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax0.0-0.10.00.8

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value2272132121801632262042873973783602733224212393113632531535291
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value2.6816.7755.9924.8354.6585.3826.8536.665
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.23.22.82.72.82.43.32.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.23.22.82.72.82.43.32.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MaterialReconcilingItems100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, hcc:MiningSegment


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value224206206175159221198280
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax98.896.897.297.397.297.696.797.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax98.896.897.297.397.297.696.797.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments hcc:MiningSegment100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:MajorCustomers, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

hcc:XcoalEnergyAndResources, us-gaap:SalesRevenueNet, us-gaap:CustomerConcentrationRisk


Revenue
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value141106380.0445768941242866374
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax62.349.721.50.019.520.117.125.14.713.120.420.320.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax62.349.721.50.019.520.117.125.14.713.120.420.320.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax hcc:XcoalEnergyAndResources us-gaap:SalesRevenueNet us-gaap:CustomerConcentrationRisk100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService

us-gaap:Product


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-09-302017-06-30
Value224206206175159221198280387369349264315412302351
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax98.896.897.297.397.297.696.797.797.497.797.196.997.797.997.196.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax98.896.897.297.397.297.696.797.797.497.797.196.997.797.997.196.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:Product100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProductAndServiceOther


Revenue
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-30
Value2.6816.7755.9924.8354.6585.3826.8536.665108.609108.3967.518.909108.99711
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.23.22.82.72.82.43.32.32.62.32.93.12.32.14.62.93.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax1.23.22.82.72.82.43.32.32.62.32.93.12.32.14.62.93.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductAndServiceOther100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Selling General And Administrative Expense

us-gaap:SellingGeneralAndAdministrativeExpense

us-gaap:SellingGeneralAndAdministrativeExpense


Selling
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value117.6377.7748.1928.4578.4567.9649.362108.9057.577.357138.234139.2438.665.17
Percentage of SellingGeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax4.93.63.74.55.23.73.93.32.72.42.12.74.22.05.63.02.42.0

Assets

us-gaap:Assets

us-gaap:Assets


Assets
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value13471379139313911397143913441349129014001395110010291301993947
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Liabilities

us-gaap:Liabilities

us-gaap:Liabilities


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value648679668631622654578603577580682734714716580194
Percentage of Liabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets48.249.348.045.444.545.443.044.744.841.548.966.869.455.158.420.5

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value13471379139313911397143913441349129014001395110010291301993947
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value6987007257597747857657457128197123653145844137520.0
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets51.850.752.054.655.554.657.055.355.258.551.133.230.644.941.679.50.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value2532482492472462442432422412402392392383253298020.0
Percentage of StockholdersEquity36.435.534.432.631.831.131.932.533.829.433.765.475.655.779.9106.50.0
Percentage of Assets18.818.017.917.817.617.018.118.018.717.217.221.723.125.033.284.60.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value0.5360.5360.5340.5330.5330.5330.5330.5330.5330.5330.5330.5340.5340.5340.5340.5330.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.20.10.10.10.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.10.00.10.10.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value4945015255615785905715535116185101388825882-49.6730.0
Percentage of StockholdersEquity70.871.672.574.074.775.274.774.271.775.571.637.828.044.220.0-6.60.0
Percentage of Assets36.736.337.740.441.441.042.541.039.644.236.612.68.619.98.3-5.20.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value-50.576-50.576-50.576-50.576-50.576-50.576-50.576-50.576-40.0-40.0-38.03-12.1-12.10.00.00.00.0
Percentage of StockholdersEquity-7.2-7.2-7.0-6.7-6.5-6.4-6.6-6.8-5.6-4.9-5.3-3.3-3.80.00.00.00.0
Percentage of Assets-3.8-3.7-3.6-3.6-3.6-3.5-3.8-3.7-3.1-2.9-2.7-1.1-1.20.00.00.00.0
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 End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value452477467502519564444462400466469367293575268290
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets33.634.633.536.137.239.233.034.331.133.333.633.428.544.227.130.7

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value2662212112162202561932081191542051305532235150
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets19.816.115.215.615.817.814.415.59.211.114.711.85.324.73.615.8

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-03-31
Value2662212112162202561932091201552061305532236235157161520.0
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets19.816.115.215.615.817.814.415.59.311.114.811.95.424.83.70.00.00.016.10.0

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

us-gaap:AccountsReceivableNetCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value65768381771319910916018213811312915211765
Percentage of AccountsReceivableNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets4.85.56.05.95.59.17.48.112.513.19.910.312.611.711.97.0

Inventory Net

us-gaap:InventoryNet

us-gaap:InventoryNet


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value7613511815515311797816970566659515439
Percentage of InventoryNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.79.88.511.211.08.27.36.15.45.04.16.15.83.95.54.2

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

us-gaap:PrepaidExpenseAndOtherAssetsCurrent


Prepaid
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3923272912
Percentage of PrepaidExpenseAndOtherAssetsCurrent100.0100.0100.0100.0100.0
Percentage of Assets2.91.82.03.01.3

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

us-gaap:PropertyPlantAndEquipmentGross

hcc:BuildingAndLeaseholdImprovements


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7774718264
Percentage of PropertyPlantAndEquipmentGross100.0100.0100.0100.0100.0
Percentage of Assets5.65.55.18.36.8
Percentage of Assets hcc:BuildingAndLeaseholdImprovements0.00.00.00.00.0

hcc:MineDevelopmentAndInfrastructureCosts


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value29133.5670.3080.0
Percentage of PropertyPlantAndEquipmentGross38.517.95.00.40.0
Percentage of Assets2.11.00.30.00.0
Percentage of Assets hcc:MineDevelopmentAndInfrastructureCosts0.00.00.00.00.0

us-gaap:ConstructionInProgress


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value8242463926
Percentage of PropertyPlantAndEquipmentGross106.256.665.447.941.5
Percentage of Assets5.93.13.44.02.8
Percentage of Assets us-gaap:ConstructionInProgress0.00.00.00.00.0

us-gaap:Land


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7172727272
Percentage of PropertyPlantAndEquipmentGross92.797.2100.888.0112.4
Percentage of Assets5.25.45.27.37.7
Percentage of Assets us-gaap:Land0.00.00.00.00.0

us-gaap:LandImprovements


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1818181111
Percentage of PropertyPlantAndEquipmentGross23.224.225.313.817.7
Percentage of Assets1.31.31.31.21.2
Percentage of Assets us-gaap:LandImprovements0.00.00.00.00.0

us-gaap:MachineryAndEquipment


Property
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value679614512441366
Percentage of PropertyPlantAndEquipmentGross876.0826.8716.3532.8565.2
Percentage of Assets48.745.736.744.438.7
Percentage of Assets us-gaap:MachineryAndEquipment0.00.00.00.00.0

Deferred Tax Assets Liabilities Net

us-gaap:DeferredTaxAssetsLiabilitiesNet

us-gaap:DeferredTaxAssetsLiabilitiesNet


Deferred
Period End2020-12-312019-12-312018-12-31
Value174154222
Percentage of DeferredTaxAssetsLiabilitiesNet100.0100.0100.0
Percentage of Assets12.511.516.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

us-gaap:OtherAssetsNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value11121415151718191921212021191816
Percentage of OtherAssetsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.90.91.01.11.11.21.41.41.51.51.51.92.11.51.91.8

Accounts Payable Current

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


Accounts
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value4865595055544650364233374030286.043
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.64.74.23.64.03.83.53.82.83.02.43.43.92.42.80.6

Accrued Liabilities Current

us-gaap:AccruedLiabilitiesCurrent

us-gaap:AccruedLiabilitiesCurrent


Accrued
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value46628667606365847069828766696647
Percentage of AccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets3.54.66.24.94.34.44.96.35.55.05.97.96.55.36.75.0

Liabilities Current

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


Liabilities
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value13016017013913113212815012112112413411512010864
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets9.711.712.210.09.49.29.611.19.48.78.912.211.29.210.96.8

Other Liabilities Current

us-gaap:OtherLiabilitiesCurrent

us-gaap:OtherLiabilitiesCurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value119.1076.3619.8867.2736.6083.9925.3275.3899.8224.9679.0396.837166.9035.307
Percentage of OtherLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.80.70.50.70.50.50.30.40.40.70.40.80.71.30.70.6

Long Term Debt

us-gaap:LongTermDebt

us-gaap:LongTermDebt


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3803803793793794093393393383384684674684683456.574
Percentage of LongTermDebt100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.227.527.327.327.228.425.225.126.324.233.642.545.536.034.80.7

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

us-gaap:LongTermDebtNoncurrent


Long
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3803803793793794093393393383384684664654653423.725
Percentage of LongTermDebtNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets28.227.527.327.327.228.425.225.126.324.233.642.445.235.834.50.4

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

us-gaap:OtherLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value37372.2583231311.1972626615.513435332.5621.153
Percentage of OtherLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.82.70.22.32.32.20.12.02.04.40.43.13.42.60.30.1

Stockholders Equity

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value6987007257597747857657457128197123653145844137520.0
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets51.850.752.054.655.554.657.055.355.258.551.133.230.644.941.679.50.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value2532482492472462442432422412402392392383253298020.0
Percentage of StockholdersEquity36.435.534.432.631.831.131.932.533.829.433.765.475.655.779.9106.50.0
Percentage of Assets18.818.017.917.817.617.018.118.018.717.217.221.723.125.033.284.60.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value0.5360.5360.5340.5330.5330.5330.5330.5330.5330.5330.5330.5340.5340.5340.5340.5330.0
Percentage of StockholdersEquity0.10.10.10.10.10.10.10.10.10.10.10.10.20.10.10.10.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.10.00.10.10.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value4945015255615785905715535116185101388825882-49.6730.0
Percentage of StockholdersEquity70.871.672.574.074.775.274.774.271.775.571.637.828.044.220.0-6.60.0
Percentage of Assets36.736.337.740.441.441.042.541.039.644.236.612.68.619.98.3-5.20.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:TreasuryStock


Stockholders
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-312016-03-31
Value-50.576-50.576-50.576-50.576-50.576-50.576-50.576-50.576-40.0-40.0-38.03-12.1-12.10.00.00.00.0
Percentage of StockholdersEquity-7.2-7.2-7.0-6.7-6.5-6.4-6.6-6.8-5.6-4.9-5.3-3.3-3.80.00.00.00.0
Percentage of Assets-3.8-3.7-3.6-3.6-3.6-3.5-3.8-3.7-3.1-2.9-2.7-1.1-1.20.00.00.00.0
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 End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value536000.0536000.0534000.0533000.0533000.0533000.0533000.0533000.0533000.0533000.0533000.0534000.0534000.0534000.0534000.0533000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.10.00.10.1

Additional Paid In Capital

us-gaap:AdditionalPaidInCapital

us-gaap:AdditionalPaidInCapital


Additional
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value253248249247246244243242241240239239238325329802
Percentage of AdditionalPaidInCapital100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets18.818.017.917.817.617.018.118.018.717.217.221.723.125.033.284.6

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


Retained
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value4945015255615785905715535116185101388825882-49.673
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets36.736.337.740.441.441.042.541.039.644.236.612.68.619.98.3-5.2

Treasury Stock Value

us-gaap:TreasuryStockValue

us-gaap:TreasuryStockValue


Treasury
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value505050505050505040403812120.0
Percentage of TreasuryStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets3.83.73.63.63.63.53.83.73.12.92.71.11.20.0

Stock Issued During Period Value New Issues

us-gaap:StockIssuedDuringPeriodValueNewIssues us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueNewIssues

us-gaap:CommonStock


Stock
Period End2021-06-302021-03-31
Value02000.0
Percentage of StockIssuedDuringPeriodValueNewIssues0.0100.0
Percentage of Assets0.00.0
Percentage of Assets us-gaap:CommonStock0.00.0

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

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdditionalPaidInCapital


Adjustments
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
Value5415000.01567000.01840000.01781000.01862000.01605000.01474000.01438000.01327000.01108000.0807000.0919000.04481000.0198000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value684530293121241502311261301021321939111616165
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax30.221.214.416.219.59.312.052.358.233.436.337.441.145.938.137.244.425.8

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-15129000.0-21792000.0-29106000.0-27831000.0-31033000.0-20219000.0-33903000.0-42455000.0-28116000.0-29739000.0-28405000.0-23805000.0-32877000.0-22542000.0-29954000.0-34408000.0-16885000.0-11378000.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-6.7-10.2-13.7-15.5-19.0-8.9-16.5-14.8-7.1-7.9-7.9-8.7-10.2-5.3-12.5-11.0-4.6-4.5

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-8.62-13.399-5.864-5.586-37.01162-6.766-18.614-238.911-147.332-26.969-3.468-366.581115-260.635-3.44-3.439-190.765
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.8-6.3-2.8-3.1-22.627.6-3.3-6.5-60.1-38.9-7.5-1.3-113.627.4-108.7-1.1-0.9-75.1

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

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect


Cash
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value4410-4.497-4.25-36.0863-16.1289-35.597-50.6637575-266.939286-199.14378141-136.59
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax19.84.7-2.1-2.4-22.027.9-7.931.1-9.0-13.420.927.5-82.867.9-83.025.138.8-53.8

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

us-gaap:DeferredIncomeTaxExpenseBenefit


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value-6.62623-10.807-8.114-4.433.276-0.077.5993227-223.0380.00.00.0
Percentage of DeferredIncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


Depreciation
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value403239272228232525222526212417231914
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

us-gaap:IncreaseDecreaseInAccountsPayable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-17.2774.9644.192-6.211.76515-5.3412-4.82110-6.566-3.843122.9313.8382.772-2.45910
Percentage of IncreaseDecreaseInAccountsPayable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Accounts Receivable

us-gaap:IncreaseDecreaseInAccountsReceivable

us-gaap:IncreaseDecreaseInAccountsReceivable


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-10.961-7.1781.8814.408-54.51732-9.774-51.589-21.8944424-16.196-22.37934-10.79535-3.62930
Percentage of IncreaseDecreaseInAccountsReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

us-gaap:IncreaseDecreaseInInventories


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-49.15516-30.422-1.7072817109.655-0.1910-9.2555.6777.174-1.78417-37.0034.33928
Percentage of IncreaseDecreaseInInventories100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value684530293121241502311261301021321939111616165
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax30.221.214.416.219.59.312.052.358.233.436.337.441.145.938.137.244.425.8

Net Income Loss

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value-4.681-21.355-33.711-14.434-9.16121204512511037452911789711912910834-33.642-50.063
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.1-10.0-15.9-8.0-5.69.510.115.731.629.2103.819.228.342.440.538.435.742.622.2-63.6-54.7

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value-4.681-21.355-33.711-14.434-9.1612120451251103745291
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-2.1-10.0-15.9-8.0-5.69.510.115.731.629.2103.819.228.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.0

Share Based Compensation

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


Share
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value5544000.01696000.01968000.01910000.01991000.01733000.01602000.01569000.01455000.01194000.0807000.0919000.04481000.0198000.03026000.0233000.0922000.00
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-15129000.0-21792000.0-29106000.0-27831000.0-31033000.0-20219000.0-33903000.0-42455000.0-28116000.0-29739000.0-28405000.0-23805000.0-32877000.0-22542000.0-29954000.0-34408000.0-16885000.0-11378000.0
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-6.7-10.2-13.7-15.5-19.0-8.9-16.5-14.8-7.1-7.9-7.9-8.7-10.2-5.3-12.5-11.0-4.6-4.5

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value149.47915232522282627242224322229341611
Percentage of PaymentsToAcquirePropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems

us-gaap:MaterialReconcilingItems


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.2990.863.1012.6452.7890.9381.7272.7720.8261.1850.8561.2360.4751.4460.9010.2830.7920.601
Percentage of PaymentsToAcquirePropertyPlantAndEquipment2.19.120.111.310.74.16.010.63.04.93.95.11.46.43.00.84.75.3

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:OperatingSegments, hcc:MiningSegment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value138.61912202321272326232122322129341610
Percentage of PaymentsToAcquirePropertyPlantAndEquipment97.990.979.988.789.395.994.089.497.095.196.194.998.693.697.099.295.394.7

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-8.62-13.399-5.864-5.586-37.01162-6.766-18.614-238.911-147.332-26.969-3.468-366.581115-260.635-3.44-3.439-190.765
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax-3.8-6.3-2.8-3.1-22.627.6-3.3-6.5-60.1-38.9-7.5-1.3-113.627.4-108.7-1.1-0.9-75.1

Payments Of Dividends

us-gaap:PaymentsOfDividends

us-gaap:PaymentsOfDividends


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-02-132018-03-312017-12-312017-09-302017-06-132017-06-302017-03-31
Value2.6162.6132.5992.5992.5992.5982.582.6042322.6062.6532.6323522.72.6856012.6772.72.673190
Percentage of PaymentsOfDividends100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

us-gaap:DeferredTaxAssetsValuationAllowance


Deferred
Period End2021-06-302021-03-312018-12-312017-12-312016-12-312015-12-31
Value47470.03127670.0
Percentage of DeferredTaxAssetsValuationAllowance100.0100.00.0100.0100.00.0

Proceeds From Sale Of Short Term Investments

us-gaap:ProceedsFromSaleOfShortTermInvestments

us-gaap:ProceedsFromSaleOfShortTermInvestments


Proceeds
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.00.00.0140.00.0170.00.00.0
Percentage of ProceedsFromSaleOfShortTermInvestments0.00.00.0100.00.00.0100.00.00.00.0

hcc:BusinessInterruption

hcc:BusinessInterruption


Business
Period End2021-06-30
Value7020000.0
Percentage of BusinessInterruption100.0

hcc:IdleMine

hcc:IdleMine


Idle
Period End2021-06-30
Value10
Percentage of IdleMine100.0

hcc:IncomeTaxReconciliationDeductibleBenefitExpenseDiscreteTaxItems

hcc:IncomeTaxReconciliationDeductibleBenefitExpenseDiscreteTaxItems


Income
Period End2021-06-302021-03-31
Value6600000.01300000.0
Percentage of IncomeTaxReconciliationDeductibleBenefitExpenseDiscreteTaxItems100.0100.0

hcc:NetIncomeLossbeforeInterestTaxesDepreciationandAmortization

hcc:NetIncomeLossbeforeInterestTaxesDepreciationandAmortization


Net
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value71521423286955901821871699713622292113191134
Percentage of NetIncomeLossbeforeInterestTaxesDepreciationandAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalOther us-gaap:StatementEquityComponents

us-gaap:AdjustmentsToAdditionalPaidInCapitalOther

us-gaap:AdditionalPaidInCapital


Adjustments
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
Value-267000.0-2539000.0-1000.00-261000.0-1012000.000-715000.0-527000.0-7000.0-54000.0-1068000.0-4320000.0
Percentage of AdjustmentsToAdditionalPaidInCapitalOther100.0100.0100.00.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0

us-gaap:AmortizationOfFinancingCostsAndDiscounts

us-gaap:AmortizationOfFinancingCostsAndDiscounts


Amortization
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.430.4250.4210.4170.3570.3510.3370.3280.3150.3810.4290.6610.7580.6380.5730.4270.4270.462
Percentage of AmortizationOfFinancingCostsAndDiscounts100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetRetirementObligationAccretionExpense

us-gaap:AssetRetirementObligationAccretionExpense


Asset
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
Value805000.0805000.0806000.0732000.0733000.0733000.0733000.0812000.0812000.0812000.01154000.01155000.01155000.01155000.0-1005000.0940000.0904000.0995000.0
Percentage of AssetRetirementObligationAccretionExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ConcentrationRiskPercentage1 us-gaap:MajorCustomers, us-gaap:ConcentrationRiskByBenchmark, us-gaap:ConcentrationRiskByType

us-gaap:ConcentrationRiskPercentage1

hcc:XcoalEnergyAndResources, us-gaap:SalesRevenueNet, us-gaap:CustomerConcentrationRisk


Concentration
Period End2021-06-302021-03-312020-09-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302016-03-31
Value63.150.922.10.1990.210.1750.260.050.130.210.20.210.164
Percentage of ConcentrationRiskPercentage1100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DerivativeGainLossOnDerivativeNet

us-gaap:DerivativeGainLossOnDerivativeNet


Derivative
Period End2021-06-30
Value-3300000.0
Percentage of DerivativeGainLossOnDerivativeNet100.0

us-gaap:DividendsCommonStockCash us-gaap:StatementEquityComponents

us-gaap:DividendsCommonStockCash

us-gaap:RetainedEarnings


Dividends
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
Value2.6162.6132.5992.5992.5992.5982.582.6052322.6062.6532.6322612.685
Percentage of DividendsCommonStockCash100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseInterestExpense

us-gaap:FinanceLeaseInterestExpense


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1122000.0774000.0585000.0315000.0542000.0546000.0567000.0786000.0395000.013000.0
Percentage of FinanceLeaseInterestExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeasePrincipalPayments

us-gaap:FinanceLeasePrincipalPayments


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value5.7378.2473.2652.9874.1523.8334.1875.4325.6971.957
Percentage of FinanceLeasePrincipalPayments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseRightOfUseAssetAmortization

us-gaap:FinanceLeaseRightOfUseAssetAmortization


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value2.7084.1253.8712.9432.9182.9983.2522.123.4211.957
Percentage of FinanceLeaseRightOfUseAssetAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate

us-gaap:IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate


Income
Period End2020-12-31
Value-8.84
Percentage of IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate100.0

us-gaap:IncomeTaxReconciliationNondeductibleExpenseDepletion

us-gaap:IncomeTaxReconciliationNondeductibleExpenseDepletion


Income
Period End2020-12-31
Value1696000.0
Percentage of IncomeTaxReconciliationNondeductibleExpenseDepletion100.0

us-gaap:IncomeTaxReconciliationTaxContingenciesStateAndLocal

us-gaap:IncomeTaxReconciliationTaxContingenciesStateAndLocal


Income
Period End2021-06-302021-03-31
Value0-22900000.0
Percentage of IncomeTaxReconciliationTaxContingenciesStateAndLocal0.0100.0

us-gaap:IncomeTaxReconciliationTaxCredits

us-gaap:IncomeTaxReconciliationTaxCredits


Income
Period End2020-09-30
Value24
Percentage of IncomeTaxReconciliationTaxCredits100.0

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable


Increase
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
Value6.6-24.2740.00.06.70.187-21.31-0.297-2.80.00.00.0
Percentage of IncreaseDecreaseInIncomeTaxesReceivable100.0100.00.00.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-10.712-5.4630.7634.388-5.549-3.538-17.962132.165-15.133-5.3522-12.6718.94814-9.01517-7.055
Percentage of IncreaseDecreaseInOtherAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets

us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets


Increase
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value-0.303-10.192100.2135.4580.2352.9921.431.657-10.167-0.0887.271.727-10.353102.2742.5072.167
Percentage of IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncrementalCommonSharesAttributableToContingentlyIssuableShares us-gaap:AwardType, us-gaap:PlanName

us-gaap:IncrementalCommonSharesAttributableToContingentlyIssuableShares

us-gaap:PhantomShareUnitsPSUs, hcc:A2016EquityPlan


Incremental
Period End2021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value43580.000043580.000043580.000043580.0
Percentage of IncrementalCommonSharesAttributableToContingentlyIssuableShares100.00.00.00.0100.00.00.00.0100.00.00.00.0100.0

us-gaap:RestrictedStockUnitsRSU, hcc:A2017EquityPlan


Incremental
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-31
Value013157.00013157.000013157.000013157.0
Percentage of IncrementalCommonSharesAttributableToContingentlyIssuableShares0.030.20.00.030.20.00.00.030.20.00.00.030.2

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements


Incremental
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value166000.0101000.0167000.00134000.0128000.0119000.077000.01000.026000.03000.06000.0000
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements us-gaap:AwardType, us-gaap:PlanName

hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions, hcc:A2017EquityPlan


Incremental
Period End2020-09-302020-06-302020-03-312019-09-302019-06-302019-03-31
Value80845.030109.023295.039983.043770.028302.0
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements48.729.813.929.834.223.8

us-gaap:RestrictedStockUnitsRSU, hcc:A2017EquityPlan


Incremental
Period End2020-09-302020-06-30
Value44252.036107.0
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements26.735.7

us-gaap:IncrementalCommonSharesAttributableToShareBasedPaymentArrangements us-gaap:PlanName

hcc:A2016EquityPlan


Incremental
Period End2020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value41640.034924.055329.0926.072366.073363.090419.0
Percentage of IncrementalCommonSharesAttributableToShareBasedPaymentArrangements25.134.633.10.054.057.376.0

us-gaap:LeaseCost

us-gaap:LeaseCost


Lease
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value5.436.0885.8424.0593.9613.8364.483.5943.8792.114
Percentage of LeaseCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:LitigationSettlementAmountAwardedFromOtherParty

us-gaap:LitigationSettlementAmountAwardedFromOtherParty


Litigation
Period End2020-12-312020-03-312019-12-312019-08-312019-09-302019-05-312019-06-30
Value1.7220.05.35.31717
Percentage of LitigationSettlementAmountAwardedFromOtherParty100.0100.00.0100.0100.0100.0100.0

us-gaap:OperatingLeaseCost

us-gaap:OperatingLeaseCost


Operating
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value1600000.01189000.01386000.0801000.0501000.0292000.0661000.0688000.063000.0144000.0
Percentage of OperatingLeaseCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherCostOfOperatingRevenue

us-gaap:OtherCostOfOperatingRevenue


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value8.3437.795117.0647.6427.5616.4827.5838.0197.745-11.6546.7047.3387.7845.4636.9857.7958.179
Percentage of OtherCostOfOperatingRevenue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherOperatingActivitiesCashFlowStatement

us-gaap:OtherOperatingActivitiesCashFlowStatement


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value0.6256.352121.1533.3112.232152.4975.6382.782-2.679-0.289-2.327-2.4762.565-0.543-3.202-0.691
Percentage of OtherOperatingActivitiesCashFlowStatement100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireMiningAssets

us-gaap:PaymentsToAcquireMiningAssets


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312016-03-31
Value1.12912134.5265.0543.6774.9946.3296.4915.5788.9370.00.00.00.0
Percentage of PaymentsToAcquireMiningAssets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.0

us-gaap:PaymentsToAcquireOtherPropertyPlantAndEquipment

us-gaap:PaymentsToAcquireOtherPropertyPlantAndEquipment


Payments
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value149.4791523252228262724
Percentage of PaymentsToAcquireOtherPropertyPlantAndEquipment100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireShortTermInvestments

us-gaap:PaymentsToAcquireShortTermInvestments


Payments
Period End2020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.00.00.08.50.09.921140.00.00.0
Percentage of PaymentsToAcquireShortTermInvestments0.00.00.0100.00.0100.0100.00.00.00.0

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities

us-gaap:ProceedsFromPaymentsForOtherFinancingActivities


Proceeds
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-03-31
Value-267000.0-2539000.000-260000.0-1012000.01000.0-2000.0-610000.0-527000.0504000.0-54000.0-1068000.0-4320000.000000
Percentage of ProceedsFromPaymentsForOtherFinancingActivities100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.00.00.0

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment


Proceeds
Period End2021-06-302021-03-312020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value172000.020000.0003000.061000.02829000.0234000.02573000.0355000.0000
Percentage of ProceedsFromSaleOfPropertyPlantAndEquipment100.0100.00.00.0100.0100.0100.0100.0100.0100.00.00.00.0

us-gaap:RelatedPartyTransactionAmountsOfTransaction us-gaap:RelatedPartyTransaction, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:RelatedPartyTransactionAmountsOfTransaction

hcc:AllocatedExpensestoJointVenture, us-gaap:CorporateJointVenture


Related
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
Value500000.0800000.0700000.0600000.0800000.0500000.0400000.0600000.0400000.0100000.0900000.0800000.0700000.0800000.01900000.0200000.0100000.0700000.0
Percentage of RelatedPartyTransactionAmountsOfTransaction100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability

us-gaap:RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability


Right
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value6.601356.9317.6422.1082.2863.4091.812382.086
Percentage of RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RoyaltyExpense

us-gaap:RoyaltyExpense


Royalty
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
Value15129.7121314111929262619233018223021
Percentage of RoyaltyExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TreasuryStockValueAcquiredCostMethod us-gaap:ShareRepurchaseProgram

us-gaap:TreasuryStockValueAcquiredCostMethod

hcc:TheNewStockRepurchaseProgram


Treasury
Period End2021-06-302021-03-312020-09-302019-12-31
Value0.0100.00.0
Percentage of TreasuryStockValueAcquiredCostMethod0.0100.00.00.0

hcc:AccruedFreightCurrent

hcc:AccruedFreightCurrent


Accrued
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2724000.01971000.04053000.05051000.02029000.0
Percentage of AccruedFreightCurrent100.0100.0100.0100.0100.0

hcc:AccruedOperatingExpensesCurrent

hcc:AccruedOperatingExpensesCurrent


Accrued
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4610201712
Percentage of AccruedOperatingExpensesCurrent100.0100.0100.0100.0100.0

hcc:AssetsHeldInTrustSelfInsuranceReserveNoncurrent

hcc:AssetsHeldInTrustSelfInsuranceReserveNoncurrent


Assets
Period End2020-12-312019-12-312018-12-312017-12-31
Value3000000.03300000.03600000.04000000.0
Percentage of AssetsHeldInTrustSelfInsuranceReserveNoncurrent100.0100.0100.0100.0

hcc:DeferredMovingCostsCurrent

hcc:DeferredMovingCostsCurrent


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value221520197.145
Percentage of DeferredMovingCostsCurrent100.0100.0100.0100.0100.0

hcc:FinanceLeaseExcludingLeasesNotYetCommencedLiability

hcc:FinanceLeaseExcludingLeasesNotYetCommencedLiability


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value64643836
Percentage of FinanceLeaseExcludingLeasesNotYetCommencedLiability100.0100.0100.0100.0

hcc:FinanceLeaseLiabilityToBePaidAfterYearFour

hcc:FinanceLeaseLiabilityToBePaidAfterYearFour


Finance
Period End2021-06-302020-09-30
Value156000.0382000.0
Percentage of FinanceLeaseLiabilityToBePaidAfterYearFour100.0100.0

hcc:InventoryRawMaterialsPurchasedPartsSuppliesandOtherNetofReserve

hcc:InventoryRawMaterialsPurchasedPartsSuppliesandOtherNetofReserve


Inventory
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value38333229302928262526232222222120
Percentage of InventoryRawMaterialsPurchasedPartsSuppliesandOtherNetofReserve100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

hcc:LesseeFinanceLeaseLeaseNotYetCommenced

hcc:LesseeFinanceLeaseLeaseNotYetCommenced


Lessee
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value3000000.01400000.01600000.02900000.04900000.04500000.02200000.02300000.01100000.0
Percentage of LesseeFinanceLeaseLeaseNotYetCommenced100.0100.0100.0100.0100.0100.0100.0100.0100.0

hcc:OperatingLossCarryforwardsIndefiniteLived us-gaap:IncomeTaxAuthority

hcc:OperatingLossCarryforwardsIndefiniteLived

us-gaap:DomesticCountry


Operating
Period End2020-12-31
Value27
Percentage of OperatingLossCarryforwardsIndefiniteLived100.0

us-gaap:StateAndLocalJurisdiction


Operating
Period End2020-12-31
Value27
Percentage of OperatingLossCarryforwardsIndefiniteLived100.0

hcc:PrepaidDepositsCurrent

hcc:PrepaidDepositsCurrent


Prepaid
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6937000.0345000.0692000.01043000.0970000.0
Percentage of PrepaidDepositsCurrent100.0100.0100.0100.0100.0

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent


Accrual
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3095000.03155000.01642000.01553000.01440000.0
Percentage of AccrualForTaxesOtherThanIncomeTaxesCurrent100.0100.0100.0100.0100.0

us-gaap:AccruedRoyaltiesCurrent

us-gaap:AccruedRoyaltiesCurrent


Accrued
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3484000.03304000.08617000.09185000.07393000.0
Percentage of AccruedRoyaltiesCurrent100.0100.0100.0100.0100.0

us-gaap:AssetRetirementObligation

us-gaap:AssetRetirementObligation


Asset
Period End2020-12-312019-12-312018-12-312017-12-312016-12-312015-12-31
Value61566199990.0
Percentage of AssetRetirementObligation100.0100.0100.0100.0100.00.0

us-gaap:AssetRetirementObligationCurrent

us-gaap:AssetRetirementObligationCurrent


Asset
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4354000.02623000.02775000.03600000.03098000.0
Percentage of AssetRetirementObligationCurrent100.0100.0100.0100.0100.0

us-gaap:AssetRetirementObligationsNoncurrent

us-gaap:AssetRetirementObligationsNoncurrent


Asset
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value61605755545453606059599998979696
Percentage of AssetRetirementObligationsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtInstrumentCarryingAmount us-gaap:CreditFacility

us-gaap:DebtInstrumentCarryingAmount

us-gaap:RevolvingCreditFacility


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value4040404040700.0
Percentage of DebtInstrumentCarryingAmount100.0100.0100.0100.0100.0100.00.0

us-gaap:DebtInstrumentCarryingAmount us-gaap:LongtermDebtType

us-gaap:SeniorNotes


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3433433433433433433433433433434754754754753500.0
Percentage of DebtInstrumentCarryingAmount858.6858.6858.6858.6858.6490.60.00.00.00.00.00.00.00.00.00.0

us-gaap:DebtInstrumentFairValue us-gaap:DebtInstrument, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentFairValue

hcc:SeniorSecuredNotesDue2024ExistingNotes, us-gaap:FairValueInputsLevel2, us-gaap:SeniorNotes


Debt
Period End2021-06-302021-03-312020-12-312020-09-30
Value349355352349
Percentage of DebtInstrumentFairValue100.0100.0100.0100.0

us-gaap:DebtInstrumentUnamortizedDiscount

us-gaap:DebtInstrumentUnamortizedDiscount


Debt
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3143000.03337000.03527000.03713000.03894000.04072000.04246000.04415000.04581000.04736000.06769000.08921000.09140000.09455000.07812000.00
Percentage of DebtInstrumentUnamortizedDiscount100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet us-gaap:DebtInstrument, us-gaap:LongtermDebtType

us-gaap:DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet

hcc:SeniorSecuredNotesDue2024ExistingNotes, us-gaap:SeniorNotes


Debt
Period End2020-12-312019-12-312018-12-312017-12-31
Value2700000.02700000.03100000.02200000.0
Percentage of DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet100.0100.0100.0100.0

us-gaap:DebtIssuanceCostsLineOfCreditArrangementsNet

us-gaap:DebtIssuanceCostsLineOfCreditArrangementsNet


Debt
Period End2020-12-312019-12-31
Value2667000.02723000.0
Percentage of DebtIssuanceCostsLineOfCreditArrangementsNet100.0100.0

us-gaap:DebtIssuanceCostsLineOfCreditArrangementsNet us-gaap:CreditFacility, us-gaap:LineOfCreditFacility

us-gaap:RevolvingCreditFacility, hcc:Citibank


Debt
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3500000.04200000.06800000.02200000.03700000.0
Percentage of DebtIssuanceCostsLineOfCreditArrangementsNet131.2154.20.00.00.0

us-gaap:DeferredIncomeTaxAssetsNet

us-gaap:DeferredIncomeTaxAssetsNet


Deferred
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value1571501741631551511541541611942220.0
Percentage of DeferredIncomeTaxAssetsNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

us-gaap:DeferredIncomeTaxLiabilities

us-gaap:DeferredIncomeTaxLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value11293104116184
Percentage of DeferredIncomeTaxLiabilities100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsGross

us-gaap:DeferredTaxAssetsGross


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value286247326429949
Percentage of DeferredTaxAssetsGross100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value253215298395896
Percentage of DeferredTaxAssetsOperatingLossCarryforwards100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsOther

us-gaap:DeferredTaxAssetsOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3614000.03649000.02767000.0197000.01963000.0
Percentage of DeferredTaxAssetsOther100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4303000.05597000.03611000.0561000.02501000.0
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value1514152337
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAssetRetirementObligations100.0100.0100.0100.0100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value9.2758.1686.727.99110
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesDeferredExpenseCapitalizedInventoryCosts

us-gaap:DeferredTaxLiabilitiesDeferredExpenseCapitalizedInventoryCosts


Deferred
Period End2020-12-31
Value558000.0
Percentage of DeferredTaxLiabilitiesDeferredExpenseCapitalizedInventoryCosts100.0

us-gaap:DeferredTaxLiabilitiesOther

us-gaap:DeferredTaxLiabilitiesOther


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2458000.02441000.01888000.01757000.02230000.0
Percentage of DeferredTaxLiabilitiesOther100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesPrepaidExpenses

us-gaap:DeferredTaxLiabilitiesPrepaidExpenses


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value108.5149.8949.4168.073
Percentage of DeferredTaxLiabilitiesPrepaidExpenses100.0100.0100.0100.0100.0

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment


Deferred
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value988292105174
Percentage of DeferredTaxLiabilitiesPropertyPlantAndEquipment100.0100.0100.0100.0100.0

us-gaap:DerivativeLiabilities us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:DerivativeLiabilities

srt:NaturalGasReserves, us-gaap:CommodityContract, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-30
Value2542000.0
Percentage of DerivativeLiabilities100.0

us-gaap:DerivativeLiabilities us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:FairValueByMeasurementFrequency

srt:NaturalGasReserves, us-gaap:CommodityContract, us-gaap:FairValueMeasurementsRecurring


Derivative
Period End2021-06-30
Value2542000.0
Percentage of DerivativeLiabilities100.0

us-gaap:DerivativeLiabilitiesCurrent us-gaap:Energy, us-gaap:DerivativeInstrumentRisk, us-gaap:HedgingDesignation

us-gaap:DerivativeLiabilitiesCurrent

srt:NaturalGasReserves, us-gaap:CommodityContract, us-gaap:Nondesignated


Derivative
Period End2021-06-30
Value2500000.0
Percentage of DerivativeLiabilitiesCurrent100.0

us-gaap:EmployeeRelatedLiabilitiesCurrent

us-gaap:EmployeeRelatedLiabilitiesCurrent


Employee
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2538372412
Percentage of EmployeeRelatedLiabilitiesCurrent100.0100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized us-gaap:AwardType, us-gaap:PlanName, us-gaap:Vesting

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

us-gaap:RestrictedStock, hcc:A2016EquityPlan, hcc:ShareBasedCompensationAwardTrancheSix


Employee
Period End2020-12-312019-12-312018-12-312017-12-31
Value100000.0400000.01000000.05700000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized100.0100.0100.0100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized us-gaap:PlanName

hcc:A2017EquityPlan


Employee
Period End2020-12-312019-12-312018-12-312017-12-31
Value3500000.02900000.01500000.0100000.0
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized3500.0725.0150.01.8

us-gaap:EnergyRelatedInventoryCoal

us-gaap:EnergyRelatedInventoryCoal


Energy
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value38102861261238769554343324337283218
Percentage of EnergyRelatedInventoryCoal100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseLiability

us-gaap:FinanceLeaseLiability


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-06-302019-03-31
Value64643836323435396.909
Percentage of FinanceLeaseLiability100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityCurrent

us-gaap:FinanceLeaseLiabilityCurrent


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value242314117.7268.022109.6148.659
Percentage of FinanceLeaseLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityNoncurrent

us-gaap:FinanceLeaseLiabilityNoncurrent


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-30
Value394024242426252731
Percentage of FinanceLeaseLiabilityNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsDue

us-gaap:FinanceLeaseLiabilityPaymentsDue


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value70714240
Percentage of FinanceLeaseLiabilityPaymentsDue100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths

us-gaap:FinanceLeaseLiabilityPaymentsDueNextTwelveMonths


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value27241615
Percentage of FinanceLeaseLiabilityPaymentsDueNextTwelveMonths100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFive


Finance
Period End2020-12-31
Value732000.0
Percentage of FinanceLeaseLiabilityPaymentsDueYearFive100.0

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour

us-gaap:FinanceLeaseLiabilityPaymentsDueYearFour


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value1353000.0732000.02557000.01964000.0
Percentage of FinanceLeaseLiabilityPaymentsDueYearFour100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree

us-gaap:FinanceLeaseLiabilityPaymentsDueYearThree


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value3.1782.557109.68
Percentage of FinanceLeaseLiabilityPaymentsDueYearThree100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo

us-gaap:FinanceLeaseLiabilityPaymentsDueYearTwo


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value2222129.68
Percentage of FinanceLeaseLiabilityPaymentsDueYearTwo100.0100.0100.0100.0

us-gaap:FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear

us-gaap:FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear


Finance
Period End2021-06-302021-03-312020-09-30
Value16213.741
Percentage of FinanceLeaseLiabilityPaymentsRemainderOfFiscalYear100.0100.0100.0

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount

us-gaap:FinanceLeaseLiabilityUndiscountedExcessAmount


Finance
Period End2021-06-302021-03-312020-12-312020-09-30
Value6874000.07061000.04418000.04509000.0
Percentage of FinanceLeaseLiabilityUndiscountedExcessAmount100.0100.0100.0100.0

us-gaap:FinanceLeaseRightOfUseAsset

us-gaap:FinanceLeaseRightOfUseAsset


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value8177464339394041415.8
Percentage of FinanceLeaseRightOfUseAsset100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseRightOfUseAssetAccumulatedAmortization

us-gaap:FinanceLeaseRightOfUseAssetAccumulatedAmortization


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value12129.88.19.04.8
Percentage of FinanceLeaseRightOfUseAssetAccumulatedAmortization100.0100.0100.0100.0100.0100.0

us-gaap:FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization

us-gaap:FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization


Finance
Period End2020-12-312019-12-31
Value5644
Percentage of FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization100.0100.0

us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent

us-gaap:FinanceLeaseWeightedAverageDiscountRatePercent


Finance
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-31
Value5.826.285.775.70.05810.05860.0602
Percentage of FinanceLeaseWeightedAverageDiscountRatePercent100.0100.0100.0100.0100.0100.0100.0

us-gaap:GuaranteeObligationsMaximumExposure us-gaap:GuaranteeObligationsByNature

us-gaap:GuaranteeObligationsMaximumExposure

us-gaap:FinancialStandbyLetterOfCredit


Guarantee
Period End2020-12-312019-12-312018-12-31
Value3.62.22.1
Percentage of GuaranteeObligationsMaximumExposure100.0100.0100.0

us-gaap:SuretyBond


Guarantee
Period End2020-12-312019-12-312018-12-31
Value404044
Percentage of GuaranteeObligationsMaximumExposure1133.31845.52114.3

us-gaap:HeldToMaturitySecuritiesCurrent

us-gaap:HeldToMaturitySecuritiesCurrent


Held
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value8.5058.5048.5048.5048.5028.514241417171717171717
Percentage of HeldToMaturitySecuritiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:HeldToMaturitySecuritiesCurrent us-gaap:FinancialInstrument

hcc:CashAndFixedIncomeSecurities


Held
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-30
Value8.58.58.58.58.58.51424
Percentage of HeldToMaturitySecuritiesCurrent99.9100.0100.0100.0100.0100.0100.2100.1

us-gaap:InterestPayableCurrent

us-gaap:InterestPayableCurrent


Interest
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4981000.04635000.06333000.04589000.00
Percentage of InterestPayableCurrent100.0100.0100.0100.00.0

us-gaap:LettersOfCreditOutstandingAmount

us-gaap:LettersOfCreditOutstandingAmount


Letters
Period End2021-06-302021-03-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value9400000.09400000.09400000.09400000.08900000.008900000.09000000.04600000.004600000.04600000.00
Percentage of LettersOfCreditOutstandingAmount100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.00.0

us-gaap:LettersOfCreditOutstandingAmount us-gaap:CreditFacility, us-gaap:LineOfCreditFacility, us-gaap:LongtermDebtType

us-gaap:RevolvingCreditFacility, hcc:Citibank, us-gaap:LetterOfCredit


Letters
Period End2020-12-31
Value9400000.0
Percentage of LettersOfCreditOutstandingAmount0.0

us-gaap:LineOfCredit us-gaap:CreditFacility, us-gaap:LineOfCreditFacility

us-gaap:LineOfCredit

us-gaap:RevolvingCreditFacility, hcc:Citibank


Line
Period End2020-12-31
Value40
Percentage of LineOfCredit100.0

us-gaap:LineOfCredit us-gaap:CreditFacility, us-gaap:LineOfCreditFacility, us-gaap:LongtermDebtType

us-gaap:RevolvingCreditFacility, hcc:Citibank, us-gaap:LetterOfCredit


Line
Period End2020-12-312019-12-31
Value9.48.9
Percentage of LineOfCredit23.50.0

us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity us-gaap:CreditFacility, us-gaap:LineOfCreditFacility

us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity

us-gaap:RevolvingCreditFacility, hcc:Citibank


Line
Period End2020-12-31
Value31
Percentage of LineOfCreditFacilityRemainingBorrowingCapacity100.0

us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity us-gaap:DebtInstrument, us-gaap:LongtermDebtType

hcc:ABLFacility, us-gaap:RevolvingCreditFacility


Line
Period End2021-06-302021-03-312020-12-312020-09-30
Value21503164
Percentage of LineOfCreditFacilityRemainingBorrowingCapacity0.00.0100.00.0

us-gaap:LongTermDebtFairValue us-gaap:DebtInstrument, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:LongtermDebtType

us-gaap:LongTermDebtFairValue

hcc:SeniorSecuredNotesDue2024ExistingNotes, us-gaap:FairValueInputsLevel2, us-gaap:SeniorNotes


Long
Period End2020-12-31
Value352
Percentage of LongTermDebtFairValue100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive


Long
Period End2020-12-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3430.00.00.00.00.00.0
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive100.00.00.00.00.00.00.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive us-gaap:LongtermDebtType

us-gaap:SeniorNotes


Long
Period End2020-12-312019-12-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value3433430.00.00.00.00.00.0
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive100.00.00.00.00.00.00.00.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour


Long
Period End2020-12-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value400.00.00.00.00.00.0
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour100.00.00.00.00.00.00.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour us-gaap:CreditFacility

us-gaap:RevolvingCreditFacility


Long
Period End2020-12-31
Value40
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour100.0

us-gaap:LongtermDebtWeightedAverageInterestRate us-gaap:CreditFacility

us-gaap:LongtermDebtWeightedAverageInterestRate

us-gaap:RevolvingCreditFacility


Longterm
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-31
Value4.04.04.03.750.03750.0375
Percentage of LongtermDebtWeightedAverageInterestRate100.0100.0100.0100.0100.0100.0

us-gaap:LongtermDebtWeightedAverageInterestRate us-gaap:LongtermDebtType

us-gaap:SeniorNotes


Longterm
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312018-12-312018-09-302017-12-31
Value8.08.08.08.00.080.080.080.080.080.08
Percentage of LongtermDebtWeightedAverageInterestRate200.0200.0200.0213.3213.3213.30.00.00.00.0

us-gaap:MineralPropertiesAccumulatedDepletion

us-gaap:MineralPropertiesAccumulatedDepletion


Mineral
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value433423144.5
Percentage of MineralPropertiesAccumulatedDepletion100.0100.0100.0100.0100.0

us-gaap:MineralPropertiesGross

us-gaap:MineralPropertiesGross


Mineral
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value144144144144147
Percentage of MineralPropertiesGross100.0100.0100.0100.0100.0

us-gaap:MineralPropertiesNet

us-gaap:MineralPropertiesNet


Mineral
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value9698100102105107110112114117120122125127130143
Percentage of MineralPropertiesNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLossCarryforwards us-gaap:IncomeTaxAuthority

us-gaap:OperatingLossCarryforwards

us-gaap:DomesticCountry


Operating
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value920785110016001900
Percentage of OperatingLossCarryforwards100.0100.0100.0100.0100.0

us-gaap:StateAndLocalJurisdiction


Operating
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value995860120016002000
Percentage of OperatingLossCarryforwards108.2109.5109.1100.0105.3

us-gaap:OtherAssetsMiscellaneousNoncurrent

us-gaap:OtherAssetsMiscellaneousNoncurrent


Other
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value4146000.09266000.09301000.07306000.04210000.0
Percentage of OtherAssetsMiscellaneousNoncurrent100.0100.0100.0100.0100.0

us-gaap:OtherPrepaidExpenseCurrent

us-gaap:OtherPrepaidExpenseCurrent


Other
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value6169000.04247000.02517000.02114000.0755000.0
Percentage of OtherPrepaidExpenseCurrent100.0100.0100.0100.0100.0

us-gaap:OtherReceivablesNetCurrent

us-gaap:OtherReceivablesNetCurrent


Other
Period End2020-12-312019-12-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value5.1421.8471.434111012145.901
Percentage of OtherReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherSundryLiabilitiesNoncurrent

us-gaap:OtherSundryLiabilitiesNoncurrent


Other
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value3031000.02701000.02258000.02263000.01911000.01679000.01197000.0942000.0759000.03070000.05510000.0
Percentage of OtherSundryLiabilitiesNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PrepaidExpenseCurrent

us-gaap:PrepaidExpenseCurrent


Prepaid
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value343445403425252726192928201929
Percentage of PrepaidExpenseCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PrepaidInsurance

us-gaap:PrepaidInsurance


Prepaid
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3832000.03631000.04670000.04955000.03140000.0
Percentage of PrepaidInsurance100.0100.0100.0100.0100.0

us-gaap:PrepaidMineralRoyaltiesNoncurrent

us-gaap:PrepaidMineralRoyaltiesNoncurrent


Prepaid
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value7.3058.97610109.847
Percentage of PrepaidMineralRoyaltiesNoncurrent100.0100.0100.0100.0100.0

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization


Property
Period End2020-12-312019-12-31
Value378273
Percentage of PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization100.0100.0

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization


Property
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302019-12-31
Value628640637607601606
Percentage of PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization100.0100.0100.0100.0100.0100.0

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization

us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization


Property
Period End2020-12-312019-12-31
Value1015879
Percentage of PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization100.0100.0

us-gaap:SelfInsuranceReserve

us-gaap:SelfInsuranceReserve


Self
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value3632263128
Percentage of SelfInsuranceReserve100.0100.0100.0100.0100.0

us-gaap:SelfInsuranceReserveCurrent

us-gaap:SelfInsuranceReserveCurrent


Self
Period End2020-12-312019-12-312018-12-312017-12-312016-12-31
Value2400000.02300000.01600000.01700000.01500000.0
Percentage of SelfInsuranceReserveCurrent100.0100.0100.0100.0100.0

us-gaap:SelfInsuranceReserveNoncurrent

us-gaap:SelfInsuranceReserveNoncurrent


Self
Period End2021-06-302021-03-312020-12-312020-09-302020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-312016-12-31
Value34343430292930252525253027
Percentage of SelfInsuranceReserveNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:TaxCreditCarryforwardAmount us-gaap:TaxCreditCarryforward

us-gaap:TaxCreditCarryforwardAmount

us-gaap:GeneralBusiness


Tax
Period End2020-12-31
Value18
Percentage of TaxCreditCarryforwardAmount100.0

Line plots across dimensions of each concept


us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
us-gaap:AwardType, us-gaap:PlanName
('hcc:RestrictedStockUnitsRSUsServiceBasedVestingConditions', None)
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amountus-gaap: Award Type, us-gaap: Plan Name
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
us-gaap:AwardType, us-gaap:PlanName
(None, 'hcc:A2017EquityPlan')
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amountus-gaap: Award Type, us-gaap: Plan Name
us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:AwardType, us-gaap:PlanName
('us-gaap:RestrictedStockUnitsRSU', None)
Allocated Share Based Compensation Expenseus-gaap: Award Type, us-gaap: Plan Name
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
Stockholders Equityus-gaap: Statement Equity Components
us-gaap:PropertyPlantAndEquipmentGross
us-gaap:PropertyPlantAndEquipmentByType
(None,)
Property Plant And Equipment Grossus-gaap: Property Plant And Equipment By Type
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
Stockholders Equityus-gaap: Statement Equity Components