CARA


Line plots across dimensions of each concept
Tables

Table of contents



us-gaap:CommonStockValue
us-gaap:StatementEquityComponents
us-gaap:SharesOutstanding

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesAuthorized

us-gaap:PreferredStockSharesAuthorized

us-gaap:CommonStockSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

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

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ProductOrService
us-gaap:ProductOrService, us-gaap:RelatedPartyTransaction
us-gaap:ProductOrService, us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersByType

us-gaap:Revenues

us-gaap:OperatingExpenses

us-gaap:ResearchAndDevelopmentExpense

us-gaap:GeneralAndAdministrativeExpense

us-gaap:OperatingIncomeLoss

us-gaap:OtherNonoperatingIncomeExpense
us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:AwardType, us-gaap:IncomeStatementLocation
us-gaap:IncomeStatementLocation
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:IncomeStatementLocation, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:IncomeStatementLocation
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:IncomeStatementLocation, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeTaxExpenseBenefit

us-gaap:ProfitLoss

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:Assets

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:AssetsCurrent

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:LiabilitiesCurrent

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:ContractWithCustomerLiabilityCurrent
us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersByType

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents

us-gaap:CommonStockValue

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue
us-gaap:StatementEquityComponents

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetIncomeLoss
us-gaap:StatementEquityComponents

us-gaap:ProfitLoss

us-gaap:DepreciationDepletionAndAmortization

us-gaap:ShareBasedCompensation

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

cara:AmortizationExpenseComponentOfLeaseExpense

cara:IncreaseDecreaseInOperatingLeaseLiabilities

cara:PercentageOfResearchAndDevelopmentTaxCreditsExchangedForCash

us-gaap:AccretionAmortizationOfDiscountsAndPremiumsInvestments

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInOtherReceivables

us-gaap:IncreaseDecreaseInPrepaidExpense
us-gaap:CounterpartyName
us-gaap:OperatingLeaseCost
us-gaap:CounterpartyName, us-gaap:IncomeStatementLocation
us-gaap:CounterpartyName
us-gaap:OperatingLeasePayments

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromStockOptionsExercised

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
us-gaap:RelatedPartyTransaction
us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum
us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
us-gaap:GranteeStatus, us-gaap:PlanName, us-gaap:Vesting
us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
us-gaap:TitleOfIndividual, us-gaap:PlanName, us-gaap:Vesting
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName
us-gaap:StockIssuedDuringPeriodSharesNewIssues
us-gaap:StatementEquityComponents
us-gaap:StockIssuedDuringPeriodSharesRestrictedStockAwardGross
us-gaap:TitleOfIndividual, us-gaap:StatementEquityComponents
us-gaap:PlanName
us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross
us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised
us-gaap:StatementEquityComponents

cara:AccruedResearchProjects

cara:AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions
us-gaap:InvestmentType

cara:PrepaidResearchAndDevelopmentExpenses

us-gaap:AccruedEmployeeBenefitsCurrent

us-gaap:AccruedProfessionalFeesCurrent
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:AssetsFairValueDisclosure
us-gaap:FairValueByMeasurementFrequency

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
us-gaap:InvestmentType

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
us-gaap:InvestmentType

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue

us-gaap:AvailableForSaleSecuritiesDebtSecurities
us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency
us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType
us-gaap:InvestmentType

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesCurrent

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesNoncurrent
us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:CashAndCashEquivalentsFairValueDisclosure
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss
us-gaap:InvestmentType

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
us-gaap:InvestmentType

us-gaap:IncomeTaxesReceivable

us-gaap:InterestReceivableCurrent
us-gaap:PropertyPlantAndEquipmentByType
us-gaap:LesseeOperatingLeaseDiscountRate

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue
us-gaap:PropertyPlantAndEquipmentByType

us-gaap:OperatingLeaseLiability

us-gaap:OtherPrepaidExpenseCurrent

us-gaap:OtherReceivablesNetCurrent

us-gaap:PrepaidExpenseCurrent

us-gaap:PrepaidInsurance
us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency
us-gaap:RestrictedCashAndCashEquivalentsNoncurrent
us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:RestrictedCashNoncurrent
us-gaap:RestrictedCashAndCashEquivalentsCashAndCashEquivalents
us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName
us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

Tables

  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:CommonStockValue ████▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▁0.0470.0470.0470.0460.040.0390.0390.0390.0340.0330.0330.0330.0270.0270.0270.0270.0270.0270.0270.0230.0230.0230.0230.0230.0230.004NANA
 us-gaap:SharesOutstanding us-gaap:StatementEquityComponents us-gaap:CommonStock████▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▁▁▁46.86440546.72772546.72022546.67397740.02791639.57504439.54755839.38951534.05921432.66225532.60848532.56748527.32415427.29686327.28286327.28286327.28286327.25486327.23158322.83691922.82491922.80203922.77859722.63841422.5924144.2882434.2882434.288243
us-gaap:CommonStockSharesIssued ████▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▁46.86440546.72772546.72022546.67397740.02791639.57504439.54755839.38951534.05921432.66225532.60848532.56748527.32415427.29686327.28286327.28286327.28286327.25486327.23158322.83691922.82491922.80203922.77859722.63841422.5924144.288243NANA
us-gaap:CommonStockSharesAuthorized █████████████████████████▁100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.050.0NANA
us-gaap:PreferredStockSharesAuthorized █████████████████████████▁5.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.05.00.0NANA
us-gaap:CommonStockSharesOutstanding ████▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▁46.86440546.72772546.72022546.67397740.02791639.57504439.54755839.38951534.05921432.66225532.60848532.56748527.32415427.29686327.28286327.28286327.28286327.25486327.23158322.83691922.82491922.80203922.77859722.63841422.5924144.288243NANA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding █▁46.79970346.724951NA44.51713439.81816239.552277NA38.03421633.315809NA32.5915532.23987727.299678NA27.28286327.28286327.259589NA25.54516422.82861222.808479NA22.7130422.60832415.654079NA4.28824315.972449
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic █▁46.79970346.724951NA44.51713439.81816239.552277NA38.03421633.315809NA32.5915532.23987727.299678NA27.28286327.28286327.259589NA25.54516422.82861222.808479NA22.7130422.60832415.654079NA4.2882434.288243
us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted █▁46.79970346.724951NA44.51713439.81816239.552277NA38.03421633.315809NA32.5915532.23987727.299678NA27.28286327.28286327.259589NA25.54516422.82861222.808479NA22.7130422.60832415.654079NA4.288243NA
 us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities us-gaap:EmployeeStockOptionNA4.93059NANANA4.925641NANANANANANA3.154617NANANA2.214492NANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax ▅▇▄▅▅▄▅▅▃▁▁▁▂▁▁▁▁▁▃▂▁▂▂▂▁▂▂█5.6348.0934.5115.7855.2084.3825.5335.0622.8740.00.00.00.9110.00.00.0790.0070.02.440.8740.4890.9141.1250.960.1780.9731.0189.973
us-gaap:Revenues ▅▇▄▅▅▄▅▅▃▁▁▁▂▁▁▁▁▁▃▂▁▂▂▂▁▂▂█5.6348.0934.5115.7855.2084.3825.5335.0622.8740.00.00.00.9110.00.00.0790.0070.02.440.8740.4890.9141.1250.960.1780.9731.0189.973
us-gaap:OperatingExpenses ▆█▇█▆▆▆▅▄▃▃▂▅▅▃▃▂▂▂▂▁▁▂▁▁▁▁▁31.51838.09434.48140.21829.3527.51627.5125.5320.68714.57112.9569.63323.23622.31511.77313.40510.9939.7297.4496.6065.2075.257.7284.6723.5993.0784.5593.054
us-gaap:ResearchAndDevelopmentExpense ▆▇▇█▆▅▅▅▄▃▂▂▅▅▃▃▂▂▂▂▁▁▂▁▁▁▁▁26.10833.53629.86435.99224.35623.60822.79922.30317.00211.5769.1516.96120.83620.2779.67110.768.5467.5685.5844.6843.3853.4596.2083.22.2011.9783.7642.021
us-gaap:GeneralAndAdministrativeExpense █▇▇▆▇▆▇▅▅▄▆▄▃▃▃▄▄▃▃▃▃▃▂▂▂▁▁▁5.414.5584.6174.2264.9943.9084.7113.2273.6852.9953.8052.6722.42.0382.1022.6452.4472.1611.8651.9221.8221.7911.521.4721.3981.10.7951.033
us-gaap:OperatingIncomeLoss ▂▂▂▁▃▃▃▃▄▄▅▅▃▃▅▅▅▅▆▆▆▆▆▆▆▆▆█-25.884-30.001-29.97-34.433-24.142-23.134-21.977-20.468-17.813-14.571-12.956-9.633-22.325-22.315-11.773-13.326-10.986-9.729-5.009-5.732-4.718-4.336-6.603-3.712-3.421-2.105-3.5416.919
us-gaap:OtherNonoperatingIncomeExpense ▄▆██▆▇█▇▄▃▃▃▁▂▂▂▂▁▁▁▁0.6340.9571.1931.2610.9471.0891.21.0020.4670.3680.3670.3310.090.1540.1760.1720.1490.0520.0220.0130.014NANANANANANANA
us-gaap:AllocatedShareBasedCompensationExpense █▇▇▇▇▄▇▁▃▁▃2.8122.6792.6722.7132.6812.2342.6421.8192.0691.812.094NANANANANANANANANANA0.340.2220.456NA0.0130.0590.04
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest ▂▂▂▁▃▃▃▃▄▄▅▅▃▃▅▅▅▅▆▆▆▆▆▆▆▇▆█-25.25-29.044-28.777-33.172-23.195-22.045-20.777-19.466-17.346-14.203-12.589-9.302-22.235-22.161-11.597-13.154-10.837-9.677-4.987-5.719-4.704-4.314-6.577-3.656-3.399-2.096-4.5755.317
us-gaap:IncomeTaxExpenseBenefit ▄▅▄▁▃▆▅▇▅▇▅█▇▄▇▆▅▅▄▇█▅▇█████-0.182-0.122-0.166-0.33-0.235-0.085-0.125-0.066-0.152-0.026-0.145-0.002-0.031-0.189-0.055-0.079-0.145-0.147-0.2-0.035-0.015-0.142-0.032-0.011-0.016-0.0030.0-0.02
us-gaap:ProfitLoss ▄▂▃▁▅▅▆▆▇█-25.068-28.922-28.611-32.842-22.96-21.96-20.652-19.4-17.194-14.177NANANANANANANANANANANANANANANANANANA
us-gaap:OtherComprehensiveIncomeLossNetOfTax █▁▃▃▃▄▂▃▃▂▃▂▃▃▃▃▃0.703-0.2380.017-0.0120.0920.187-0.1270.070.057-0.110.053-0.0370.021-0.017-0.0210.0370.039NANANANANANANANANANANA
us-gaap:NetIncomeLoss ▂▂▂▁▃▃▃▃▄▄▅▅▃▃▅▅▅▅▆▆▆▆▆▆▆▇▆█-25.068-28.922-28.611-32.842-22.96-21.96-20.652-19.4-17.194-14.177-12.444-9.3-22.204-21.971-11.542-13.075-10.692-9.53-4.787-5.684-4.689-4.172-6.545-3.645-3.383-2.093-4.5755.337
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings█▁-25.068-28.922NA-32.842-22.96-21.96-20.652-19.4-17.194-14.177-12.444-9.3-22.204-21.972-11.542-13.074-10.692-9.53-4.787-5.684-4.689-4.172-6.545-3.645-3.383-2.093-4.5755.337
us-gaap:ComprehensiveIncomeNetOfTax ▃▂▂▁▃▄▄▄▅▆▆▇▄▄▆▆▇▇███-24.365-29.16-28.594-32.854-22.868-21.773-20.779-19.33-17.137-14.287-12.391-9.337-22.183-21.989-11.563-13.038-10.653-9.565-4.787-5.684-4.689NANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:Assets ▅▆▇█▅▅▆▇▄▃▄▄▂▂▃▃▃▄▄▂▂▂▂▂▃▁168.613196.173232.959263.795149.641170.587190.823212.704139.89397.004108.047117.97343.29963.82880.15292.045102.013110.897117.89746.44151.65455.93462.37268.19471.55518.083NANA
us-gaap:LiabilitiesAndStockholdersEquity ▅▆▇█▄▅▆▆▄▃▃▃▁▂▂▃▃▃▃▁▁▁168.613196.173232.959263.795149.641170.587190.823212.704139.89397.004108.047117.97343.29963.82880.15292.045102.013110.897117.89746.44151.65455.934NANANANANANA
us-gaap:StockholdersEquity ▆▇▇█▅▅▆▆▄▅▅▅▃▄▄▅▅▅▅▄▄▄▄▄▄▁▁▁140.928160.474186.713211.89499.545114.522133.63149.5373.07686.7899.074109.2229.26950.72571.80282.58894.927105.044113.86342.4747.42451.66255.33561.56864.728-54.075-51.995-48.428
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:AssetsCurrent ▆▅▆█▅▆▆█▅▄▄▅▂▃▃▄▄▄▅▂▂▂▃▃▃▁141.915132.669165.656203.462124.771144.159168.139211.388138.52695.058105.976115.80541.03161.44577.01889.14399.474108.934115.6844.03149.05753.1559.4165.05568.22614.558NANA
us-gaap:CashAndCashEquivalentsAtCarryingValue ▄▂▂▃▂▂▂▇▂▁▂▁▁▂▁▁▁▂█▄▄▄▅▅▅▂▂▂56.96717.03618.30534.70518.49414.18815.08196.72917.8029.38811.7929.4165.30612.0925.4263.5457.92215.101111.11643.19147.42252.66358.39362.81267.03812.35717.73321.178
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:PropertyPlantAndEquipmentNet ▁▁▁▁▂▂▂▂▂▃▃▄▄▄▄▄▂▃▄▄▅▆▆▇▇█0.6040.6520.70.7480.7980.8410.880.9080.9591.1771.3021.3991.4991.6141.6651.4331.071.2631.5171.711.8972.0842.2622.4392.6292.825NANA
us-gaap:OperatingLeaseRightOfUseAsset ▁▃█2.8252.8763.036NANANANANANANANANANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:LiabilitiesCurrent ▄▆▇█▇▇▇▇▆▂▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁24.72632.60342.89448.29940.16242.40540.44743.24534.8238.5067.2727.1912.51211.5336.8258.1686.0895.2683.3743.2393.4273.3986.0935.6175.7535.433NANA
us-gaap:AccountsPayableCurrent ▄███▃▄▄▃▃▄▂▂▂▄▂▃▂▂▂▁▁▁▂▂▂▁4.8289.3099.19.5362.4854.9434.3712.6383.6923.8291.1871.8651.6884.7382.3872.9312.3481.9651.2630.7110.9380.5151.7151.1911.5860.676NANA
us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent ▆▇██▅▅▅▆▅▃▃▃▅▅▃▃▃▂▂▁▁▁▂▁▁▁13.95217.37119.66520.58112.76613.3113.62214.00312.5538.5067.2727.1912.51211.5336.8258.1686.0895.2683.3743.152.4641.9464.1492.5482.3361.958NANA
us-gaap:OperatingLeaseLiabilityCurrent █▆▄▁1.0060.9910.9670.945NANANANANANANANANANANANANANANANANANANANANANANANA
us-gaap:ContractWithCustomerLiabilityCurrent ▁▃▅▇▇█▇█▅9.76814.24122.26226.77326.47328.19426.82529.24222.27NANANANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:OperatingLeaseLiabilityNoncurrent ▁▂▅█2.9593.0963.3523.602NANANANANANANANANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:StockholdersEquity ▆▇▇█▅▅▆▆▄▅▅▅▃▄▄▅▅▅▅▄▄▄▄▄▄▁▁▁140.928160.474186.713211.89499.545114.522133.63149.5373.07686.7899.074109.2229.26950.72571.80282.58894.927105.044113.86342.4747.42451.66255.33561.56864.728-54.075-51.995-48.428
us-gaap:CommonStockValue ████▇▇▇▇▆▆▆▆▅▅▅▅▅▅▅▄▄▄▄▄▄▁0.0470.0470.0470.0460.040.0390.0390.0390.0340.0330.0330.0330.0270.0270.0270.0270.0270.0270.0270.0230.0230.0230.0230.0230.0230.004NANA
us-gaap:AdditionalPaidInCapitalCommonStock ████▆▆▅▅▄▄▄▄▄▂▂▂▂▂▂▁▁▁594.963590.144587.223583.811438.614430.724428.059423.18327.401307.158305.165302.92300.151212.866211.954211.177210.479209.943209.197133.021132.291131.84NANANA8.377NANA
us-gaap:RetainedEarningsAccumulatedDeficit ▁▁▂▂▃▃▄▄▅▅▅▆▆▆▇▇▇▇▇▇██████-454.717-429.649-400.727-372.116-339.274-316.314-294.354-273.702-254.302-220.341-206.164-193.72-184.42-162.171-140.199-128.657-115.583-104.891-95.361-90.574-84.89-80.201-76.029-69.484-65.839-62.456NANA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax █▁▄▃▄▃▁▂▂▁▂▂▂▂▂▂▂▂0.635-0.0680.170.1530.1650.073-0.1140.013-0.057-0.070.04-0.0130.0240.0030.020.0410.004-0.035NANANA0.0NANANANANANA
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue █▁2.9932.846NA2.8352.6812.2342.0261.8192.0691.7471.621.3181.1080.8290.7770.6980.4960.7070.6610.7010.4450.340.2220.4560.3530.0130.059NA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInOperatingActivities ▂▁▂▂▂▂▂▃█▃▄-27.652-38.303-31.166-25.637-24.896-27.526-24.361-20.49241.02-11.413-9.851NANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInInvestingActivities █▇▆▁▆▆▃▅▃▅▆67.38236.95914.738-96.88125.22826.399-57.8315.454-51.1368.12612.076NANANANANANANANANANANANANANANANANA
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▁▁█▁▁▁▆▂▁▁0.2010.0750.028138.3683.9740.2340.54493.96516.0410.1830.151NANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInOperatingActivities ▂▁▂▂▂▂▂▃█▃▄-27.652-38.303-31.166-25.637-24.896-27.526-24.361-20.49241.02-11.413-9.851NANANANANANANANANANANANANANANANANA
us-gaap:NetIncomeLoss ▂▂▂▁▃▃▃▃▄▄▅▅▃▃▅▅▅▅▆▆▆▆▆▆▆▇▆█-25.068-28.922-28.611-32.842-22.96-21.96-20.652-19.4-17.194-14.177-12.444-9.3-22.204-21.971-11.542-13.075-10.692-9.53-4.787-5.684-4.689-4.172-6.545-3.645-3.383-2.093-4.5755.337
 us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents us-gaap:RetainedEarnings█▁-25.068-28.922NA-32.842-22.96-21.96-20.652-19.4-17.194-14.177-12.444-9.3-22.204-21.972-11.542-13.074-10.692-9.53-4.787-5.684-4.689-4.172-6.545-3.645-3.383-2.093-4.5755.337
us-gaap:ProfitLoss ▄▂▃▁▅▅▆▆▇█-25.068-28.922-28.611-32.842-22.96-21.96-20.652-19.4-17.194-14.177NANANANANANANANANANANANANANANANANANA
us-gaap:DepreciationDepletionAndAmortization ▁▁▁▁▁▁▁▁▂▂▂▂▂▂▂▆█▃▂▂▂▂▃▃▃▃▃▃0.0480.0480.0480.050.050.050.0520.0790.1140.1250.1250.1230.1220.1190.0970.5190.730.2590.1940.1930.1930.1930.1970.1960.1970.1970.1970.197
us-gaap:ShareBasedCompensation █▆▆▆▇▅▇▄▄▄▄▃▃▃▃▂▂▂▂▂▂▂▂▃▁▂▂▂4.6192.8463.3862.9334.0152.2343.7191.8192.0691.7471.621.3181.1080.8290.7770.6980.4960.7070.6610.7010.4450.340.2221.162-0.3530.0130.0590.062
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInInvestingActivities █▇▆▁▆▆▃▅▃▅▆67.38236.95914.738-96.88125.22826.399-57.8315.454-51.1368.12612.076NANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
us-gaap:NetCashProvidedByUsedInFinancingActivities ▁▁▁█▁▁▁▆▂▁▁0.2010.0750.028138.3683.9740.2340.54493.96516.0410.1830.151NANANANANANANANANANANANANANANANANA
  2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30

None

us-gaap:CommonStockValue

us-gaap:CommonStockValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value47000.047000.047000.046000.040000.039000.039000.039000.034000.033000.033000.033000.033000.027000.027000.027000.027000.027000.027000.027000.023000.023000.023000.023000.023000.023000.04000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:SharesOutstanding us-gaap:StatementEquityComponents

us-gaap:SharesOutstanding

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value46464646403939393432323232272727272727272222222222224.2882434.2882434.2882434.2882433.3286983.236637
Percentage of SharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:CommonStockSharesIssued

us-gaap:CommonStockSharesIssued


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-05-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312014-01-302013-12-31
Value46464646400.0741663939393432323232272727272727272222222222225.754.288243
Percentage of CommonStockSharesIssued100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:CommonStockSharesAuthorized

us-gaap:CommonStockSharesAuthorized


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312014-01-162013-12-31
Value10010010010010010010010010010010010010010010010010010010010010010010010010010010050
Percentage of CommonStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:PreferredStockSharesAuthorized

us-gaap:PreferredStockSharesAuthorized


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312014-01-162013-12-31
Value5000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.05000000.00
Percentage of PreferredStockSharesAuthorized100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0

None

us-gaap:CommonStockSharesOutstanding

us-gaap:CommonStockSharesOutstanding


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value46464646403939393432323232272727272727272222222222224.288243
Percentage of CommonStockSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value46464439393833323232272727272522222222154.288243153.659208
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-06-302013-03-31
Value46464439393833323232272727272522222222154.2882434.2882433.659208
Percentage of WeightedAverageNumberOfSharesOutstandingBasic100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted

us-gaap:WeightedAverageNumberOfShareOutstandingBasicAndDiluted


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-09-302018-06-302018-03-312017-09-302017-06-302017-03-312016-09-302016-06-302016-03-312015-09-302015-06-302015-03-312014-09-302014-06-302014-03-312013-09-302013-03-31
Value46464439393833323232272727272522222222154.2882433.659208
Percentage of WeightedAverageNumberOfShareOutstandingBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:EmployeeStockOption


None
Period End2020-03-312019-03-312018-03-312017-03-312016-03-31
Value4.930594.9256413.9329923.1546172.214492
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount100.0100.0100.0100.0100.0

None

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value5.6348.0934.5115.7855.2084.3825.5335.0622.8740.00.00.00.9110.00.00.0790.0070.02.440.8740.4890.9141.1250.960.1780.9731.0189.973
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService

cara:ClinicalCompoundRevenue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-312017-09-30
Value0.5350.0720.00.00.00.140.00.0330.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax9.50.90.00.00.03.20.00.70.00.0
Percentage of Revenues9.50.90.00.00.03.20.00.70.00.0
Percentage of Revenues cara:ClinicalCompoundRevenue0.00.00.00.00.00.00.00.00.00.0

cara:LicenseAndMilestoneFees


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-30
Value5.0998.0214.5115.7855.2084.2425.5335.0292.8740.00.0
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax90.599.1100.0100.0100.096.8100.099.3100.00.00.0
Percentage of Revenues90.599.1100.0100.0100.096.8100.099.3100.00.00.0
Percentage of Revenues cara:LicenseAndMilestoneFees0.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:RelatedPartyTransaction

cara:ClinicalCompoundRevenue, cara:MaruishiPharmaceuticalCompanyLimited


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value0.4470.0720.00.00.00.140.0329673.3e-05
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax7.90.90.00.00.03.20.60.0
Percentage of Revenues7.90.90.00.00.03.20.60.0
Percentage of Revenues cara:ClinicalCompoundRevenue cara:MaruishiPharmaceuticalCompanyLimited0.00.00.00.00.00.00.00.0

cara:ClinicalCompoundRevenue, cara:ViforFreseniusMedicalCareRenalPharmaLimited


None
Period End2020-06-30
Value0.088
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax1.6
Percentage of Revenues1.6
Percentage of Revenues cara:ClinicalCompoundRevenue cara:ViforFreseniusMedicalCareRenalPharmaLimited0.0

us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax us-gaap:ProductOrService, us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersByType

cara:LicenseAndMilestoneFees, cara:LicenseAgreementWithChongKunDangPharmaceutical


None
Period End2020-06-30
Value0.626
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax11.1
Percentage of Revenues11.1
Percentage of Revenues cara:LicenseAndMilestoneFees cara:LicenseAgreementWithChongKunDangPharmaceutical0.0

cara:LicenseAndMilestoneFees, cara:LicenseAgreementWithViforFreseniusMedicalCareRenalPharmaLimited


None
Period End2020-06-302020-03-312019-12-312019-09-30
Value4.4738.021175.785
Percentage of RevenueFromContractWithCustomerExcludingAssessedTax79.499.1397.8100.0
Percentage of Revenues79.499.1397.8100.0
Percentage of Revenues cara:LicenseAndMilestoneFees cara:LicenseAgreementWithViforFreseniusMedicalCareRenalPharmaLimited0.00.00.00.0

None

us-gaap:Revenues

us-gaap:Revenues


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-30
Value5.6348.0934.5115.7855.2084.3825.5335.0622.8740.00.00.00.9110.00.00.0790.0070.02.440.8740.4890.9141.1250.960.1780.9731.0189.973
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.00.0100.00.00.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:OperatingExpenses

us-gaap:OperatingExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value3138344029272725201714129.63323221113109.7297.4496.6065.2075.257.7284.6723.5993.0784.5593.0541.51
Percentage of OperatingExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues559.4470.7764.4695.2563.6627.9497.2504.3719.80.00.00.00.02550.60.00.016968.4157042.90.0305.3755.81064.8574.4686.9486.72021.9316.3447.830.60.0

None

us-gaap:ResearchAndDevelopmentExpense

us-gaap:ResearchAndDevelopmentExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value26332935242322221713119.1516.96120209.671108.5467.5685.5844.6843.3853.4596.2083.22.2011.9783.7642.0210.922
Percentage of ResearchAndDevelopmentExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues463.4414.4662.0622.2467.7538.7412.1440.6591.60.00.00.00.02287.20.00.013620.3122085.70.0228.9535.9692.2378.4551.8333.31236.5203.3369.720.30.0

None

us-gaap:GeneralAndAdministrativeExpense

us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value5.414.5584.6174.2264.9943.9084.7113.2273.6853.6972.9953.8052.6722.42.0382.1022.6452.4472.1611.8651.9221.8221.7911.521.4721.3981.10.7951.0330.588
Percentage of GeneralAndAdministrativeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues96.056.3102.373.195.989.285.163.7128.20.00.00.00.0263.40.00.03348.134957.10.076.4219.9372.6196.0135.1153.3785.4113.178.110.40.0

None

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25884000.0-30001000.0-29970000.0-34433000.0-24142000.0-23134000.0-21977000.0-20468000.0-17813000.0-17124000.0-14571000.0-12956000.0-9633000.0-22325000.0-22315000.0-11773000.0-13326000.0-10986000.0-9729000.0-5009000.0-5732000.0-4718000.0-4336000.0-6603000.0-3712000.0-3421000.0-2105000.0-3541000.06919000.0-1510000.0
Percentage of OperatingIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-459.4-370.7-664.4-595.2-463.6-527.9-397.2-404.3-619.80.00.00.00.0-2450.60.00.0-16868.4-156942.90.0-205.3-655.8-964.8-474.4-586.9-386.7-1921.9-216.3-347.869.40.0

None

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value634000.0957000.01193000.01261000.0947000.01089000.01200000.01002000.0467000.0311000.0368000.0367000.0331000.090000.0154000.0176000.0172000.0149000.052000.022000.013000.014000.0
Percentage of OtherNonoperatingIncomeExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues11.311.826.421.818.224.921.719.816.20.00.00.00.09.90.00.0217.72128.60.00.91.52.9

us-gaap:OtherNonoperatingIncomeExpense us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss


None
Period End2020-06-302018-12-312018-09-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value60000.027000.0-17000.0-15000.01000.01000.003000.011000.012000.0
Percentage of OtherNonoperatingIncomeExpense9.52.2-1.7-4.80.30.30.03.37.16.8
Percentage of Revenues1.10.5-0.30.00.00.00.00.30.00.0
Percentage of Revenues us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedNetUnrealizedInvestmentGainLoss0.00.00.00.00.00.00.00.00.00.0

None

us-gaap:AllocatedShareBasedCompensationExpense

us-gaap:AllocatedShareBasedCompensationExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302013-12-312013-09-302013-06-30
Value2.8122.6792.6722.7132.6812.2342.6421.8192.0691.8711.812.0940.340.2220.4560.0130.0590.04
Percentage of AllocatedShareBasedCompensationExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues49.933.159.246.951.551.047.735.972.00.00.00.037.219.747.51.35.80.4

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:AwardType, us-gaap:IncomeStatementLocation

us-gaap:RestrictedStockUnitsRSU, us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-09-302019-06-30
Value0.5510.030.00.59
Percentage of AllocatedShareBasedCompensationExpense19.61.10.022.0
Percentage of Revenues9.80.40.011.3
Percentage of Revenues us-gaap:RestrictedStockUnitsRSU us-gaap:GeneralAndAdministrativeExpense0.00.00.00.0

us-gaap:RestrictedStockUnitsRSU, us-gaap:ResearchAndDevelopmentExpense


None
Period End2020-06-302020-03-312019-09-302019-06-30
Value1.1330.0140.00.604
Percentage of AllocatedShareBasedCompensationExpense40.30.50.022.5
Percentage of Revenues20.10.20.011.6
Percentage of Revenues us-gaap:RestrictedStockUnitsRSU us-gaap:ResearchAndDevelopmentExpense0.00.00.00.0

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:IncomeStatementLocation

us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302013-12-312013-09-302013-06-30
Value1.1421.071.2651.3221.3551.1521.1240.9181.2171.2221.1611.4750.260.1840.2970.0040.0280.017
Percentage of AllocatedShareBasedCompensationExpense40.639.947.348.750.551.642.550.558.865.364.170.476.582.965.130.847.542.5
Percentage of Revenues20.313.228.022.926.026.320.318.142.30.00.00.028.416.430.90.42.80.2
Percentage of Revenues us-gaap:GeneralAndAdministrativeExpense0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:ResearchAndDevelopmentExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302014-12-312014-09-302014-06-302013-12-312013-09-302013-06-30
Value1.671.6091.4071.3911.3261.0821.5180.9010.8520.6490.6490.6190.080.0380.1590.0090.0310.023
Percentage of AllocatedShareBasedCompensationExpense59.460.152.751.349.548.457.549.541.234.735.929.623.517.134.969.252.557.5
Percentage of Revenues29.619.931.224.025.524.727.417.829.60.00.00.08.83.416.60.93.00.2
Percentage of Revenues us-gaap:ResearchAndDevelopmentExpense0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:IncomeStatementLocation, us-gaap:PlanName

srt:Director, cara:June2019, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, us-gaap:GeneralAndAdministrativeExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-30
Value0.082
Percentage of AllocatedShareBasedCompensationExpense2.9
Percentage of Revenues1.5
Percentage of Revenues srt:Director cara:June2019 us-gaap:RestrictedStockUnitsRSU us-gaap:ShareBasedPaymentArrangementNonemployee us-gaap:GeneralAndAdministrativeExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.0

srt:Director, cara:June2020, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, us-gaap:GeneralAndAdministrativeExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-30
Value0.04
Percentage of AllocatedShareBasedCompensationExpense1.4
Percentage of Revenues0.7
Percentage of Revenues srt:Director cara:June2020 us-gaap:RestrictedStockUnitsRSU us-gaap:ShareBasedPaymentArrangementNonemployee us-gaap:GeneralAndAdministrativeExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.0

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

srt:Director, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-03-31
Value0.123
Percentage of AllocatedShareBasedCompensationExpense4.6
Percentage of Revenues1.5
Percentage of Revenues srt:Director us-gaap:RestrictedStockUnitsRSU us-gaap:ShareBasedPaymentArrangementNonemployee cara:TwoThousandAndFourteenEquityIncentivePlan0.0

us-gaap:AllocatedShareBasedCompensationExpense us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:IncomeStatementLocation

srt:Director, us-gaap:RestrictedStockUnitsRSU, us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-30
Value0.1220.1230.1230.1230.041
Percentage of AllocatedShareBasedCompensationExpense4.34.64.64.51.5
Percentage of Revenues2.21.52.72.10.8
Percentage of Revenues srt:Director us-gaap:RestrictedStockUnitsRSU us-gaap:GeneralAndAdministrativeExpense0.00.00.00.00.0

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

srt:ExecutiveOfficer, cara:TimeBasedRestrictedStockUnits, us-gaap:GeneralAndAdministrativeExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-31
Value0.0950.03
Percentage of AllocatedShareBasedCompensationExpense3.41.1
Percentage of Revenues1.70.4
Percentage of Revenues srt:ExecutiveOfficer cara:TimeBasedRestrictedStockUnits us-gaap:GeneralAndAdministrativeExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

srt:ExecutiveOfficer, cara:TimeBasedRestrictedStockUnits, us-gaap:ResearchAndDevelopmentExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-31
Value0.0470.014
Percentage of AllocatedShareBasedCompensationExpense1.70.5
Percentage of Revenues0.80.2
Percentage of Revenues srt:ExecutiveOfficer cara:TimeBasedRestrictedStockUnits us-gaap:ResearchAndDevelopmentExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, us-gaap:GeneralAndAdministrativeExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302019-06-30
Value0.4560.59
Percentage of AllocatedShareBasedCompensationExpense16.222.0
Percentage of Revenues8.111.3
Percentage of Revenues srt:ExecutiveOfficer us-gaap:RestrictedStockUnitsRSU us-gaap:GeneralAndAdministrativeExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, us-gaap:ResearchAndDevelopmentExpense, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302019-06-30
Value1.0870.604
Percentage of AllocatedShareBasedCompensationExpense38.722.5
Percentage of Revenues19.311.6
Percentage of Revenues srt:ExecutiveOfficer us-gaap:RestrictedStockUnitsRSU us-gaap:ResearchAndDevelopmentExpense cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

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

srt:ExecutiveOfficer, cara:TimeBasedRestrictedStockUnits, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-31
Value0.1420.044
Percentage of AllocatedShareBasedCompensationExpense5.01.6
Percentage of Revenues2.50.5
Percentage of Revenues srt:ExecutiveOfficer cara:TimeBasedRestrictedStockUnits cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302019-06-30
Value1.5431.194
Percentage of AllocatedShareBasedCompensationExpense54.944.5
Percentage of Revenues27.422.9
Percentage of Revenues srt:ExecutiveOfficer us-gaap:RestrictedStockUnitsRSU cara:TwoThousandAndFourteenEquityIncentivePlan0.00.0

None

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25250000.0-29044000.0-28777000.0-33172000.0-23195000.0-22045000.0-20777000.0-19466000.0-17346000.0-16813000.0-14203000.0-12589000.0-9302000.0-22235000.0-22161000.0-11597000.0-13154000.0-10837000.0-9677000.0-4987000.0-5719000.0-4704000.0-4314000.0-6577000.0-3656000.0-3399000.0-2096000.0-4575000.05317000.0-2639000.0
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-448.2-358.9-637.9-573.4-445.4-503.1-375.5-384.6-603.50.00.00.00.0-2440.70.00.0-16650.6-154814.30.0-204.4-654.3-962.0-472.0-584.6-380.8-1909.6-215.4-449.453.30.0

None

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-182000.0-122000.0-166000.0-330000.0-235000.0-85000.0-125000.0-66000.0-152000.0-46000.0-26000.0-145000.0-2000.0-31000.0-189000.0-55000.0-79000.0-145000.0-147000.0-200000.0-35000.0-15000.0-142000.0-32000.0-11000.0-16000.0-3000.00-20000.0-7000.0
Percentage of IncomeTaxExpenseBenefit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0
Percentage of Revenues-3.2-1.5-3.7-5.7-4.5-1.9-2.3-1.3-5.30.00.00.00.0-3.40.00.0-100.0-2071.40.0-8.2-4.0-3.1-15.5-2.8-1.1-9.0-0.30.0-0.20.0

None

us-gaap:ProfitLoss

us-gaap:ProfitLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-25068000.0-28922000.0-28611000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-634.2-567.7-440.9-501.1-373.3-383.2-598.30.00.0

None

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value703000.0-238000.017000.0-12000.092000.0187000.0-127000.070000.057000.0-44000.0-110000.053000.0-37000.021000.0-17000.0-21000.037000.039000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues12.5-2.90.4-0.21.84.3-2.31.42.00.00.00.00.02.30.00.046.8557.1

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value703000.0-238000.0-12000.092000.0187000.0-127000.070000.057000.0-44000.0-110000.053000.0-37000.021000.0-17000.0-21000.037000.039000.0
Percentage of OtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues12.5-2.9-0.21.84.3-2.31.42.00.00.00.00.02.30.00.046.8557.1
Percentage of Revenues us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25068000.0-28922000.0-28611000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0-12444000.0-9300000.0-22204000.0-21971000.0-11542000.0-13075000.0-10692000.0-9530000.0-4787000.0-5684000.0-4689000.0-4172000.0-6545000.0-3645000.0-3383000.0-2093000.0-4575000.05337000.0-2632000.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-634.2-567.7-440.9-501.1-373.3-383.2-598.30.00.00.00.0-2437.30.00.0-16550.6-152742.90.0-196.2-650.3-958.9-456.5-581.8-379.7-1900.6-215.1-449.453.50.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25068000.0-28922000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0-12444000.0-9300000.0-22204000.0-21972000.0-11542000.0-13074000.0-10692000.0-9530000.0-4787000.0-5684000.0-4689000.0-4172000.0-6545000.0-3645000.0-3383000.0-2093000.0-4575000.05337000.0-2632000.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-567.7-440.9-501.1-373.3-383.2-598.30.00.00.00.0-2437.30.00.0-16549.4-152742.90.0-196.2-650.3-958.9-456.5-581.8-379.7-1900.6-215.1-449.453.50.0
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value-24365000.0-29160000.0-28594000.0-32854000.0-22868000.0-21773000.0-20779000.0-19330000.0-17137000.0-16811000.0-14287000.0-12391000.0-9337000.0-22183000.0-21989000.0-11563000.0-13038000.0-10653000.0-9565000.0-4787000.0-5684000.0-4689000.0
Percentage of ComprehensiveIncomeNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-432.5-360.3-633.9-567.9-439.1-496.9-375.5-381.9-596.30.00.00.00.0-2435.00.00.0-16503.8-152185.70.0-196.2-650.3-958.9

None

us-gaap:Assets

us-gaap:Assets


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value16819623226314917019021213980971081174363809210211011746515562687118
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:LiabilitiesAndStockholdersEquity

us-gaap:LiabilitiesAndStockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-31
Value168196232263149170190212139809710811743638092102110117465155
Percentage of LiabilitiesAndStockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value14016018621199114133149737286991092950718294105113424751556164-54.075-51.995-48.428-55.267-58.133-52.064
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets83.681.880.180.366.567.170.070.352.289.489.591.792.667.679.589.689.793.194.796.691.491.892.488.790.390.5-299.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.635-0.0680.170.1530.1650.073-0.1140.013-0.057-0.114-0.070.04-0.0130.0240.0030.020.0410.004-0.035
Percentage of StockholdersEquity0.5-0.00.10.10.20.1-0.10.0-0.1-0.2-0.10.0-0.00.10.00.00.00.0-0.0
Percentage of Assets0.4-0.00.10.10.10.0-0.10.0-0.0-0.1-0.10.0-0.00.10.00.00.00.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value5945905875834384304284233273093073053023002122112112102092091331321311311311308.3778.3647.3565.8541.2481.046
Percentage of StockholdersEquity422.2367.8314.5275.5440.6376.1320.3283.0448.0429.0354.0308.0277.31025.5419.6295.2255.7221.7199.9183.7313.2279.0255.2237.4212.8201.7-15.5-16.1-15.2-10.6-2.1-2.0
Percentage of Assets352.9300.8252.1221.3293.1252.5224.3199.0234.0383.6316.6282.4256.8693.2333.5264.4229.4206.3189.3177.4286.4256.1235.7210.6192.1182.446.30.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value0.0470.0470.0470.0460.040.0390.0390.0390.0340.0330.0330.0330.0330.0270.0270.0270.0270.0270.0270.0270.0230.0230.0230.0230.0230.0230.0040.0040.0040.0040.0030.003
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.10.00.00.00.00.00.10.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value-454.717-429.649-400.727-372.116-339.274-316.314-294.354-273.702-254.302-237.108-220.341-206.164-193.72-184.42-162.171-140.199-128.657-115.583-104.891-95.361-90.574-84.89-80.201-76.029-69.484-65.839-62.456-60.363-55.788-61.125-59.384-53.113
Percentage of StockholdersEquity-322.7-267.7-214.6-175.6-340.8-276.2-220.3-183.0-348.0-328.8-253.9-208.1-177.4-630.1-319.7-195.3-155.8-121.8-99.9-83.8-213.3-179.0-155.2-137.4-112.9-101.7115.5116.1115.2110.6102.2102.0
Percentage of Assets-269.7-219.0-172.0-141.1-226.7-185.4-154.3-128.7-181.8-294.1-227.1-190.8-164.2-425.9-254.1-174.9-139.8-113.3-94.6-80.9-195.0-164.3-143.4-121.9-101.9-92.0-345.40.00.00.00.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:AssetsCurrent

us-gaap:AssetsCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1411321652031241441682111387895105115416177899910811544495359656814
Percentage of AssetsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets84.267.671.177.183.484.588.199.499.097.798.098.198.294.896.396.196.897.598.298.194.895.095.095.395.495.380.5

None

us-gaap:CashAndCashEquivalentsAtCarryingValue

us-gaap:CashAndCashEquivalentsAtCarryingValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value561718341814159617119.388119.4165.306125.4263.5457.922151114347525862671217210.691.1174.097
Percentage of CashAndCashEquivalentsAtCarryingValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets33.88.77.913.212.48.37.945.512.714.79.710.98.012.318.96.83.97.813.694.293.091.894.293.692.193.768.30.00.00.00.00.0

None

us-gaap:PropertyPlantAndEquipmentNet

us-gaap:PropertyPlantAndEquipmentNet


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value604000.0652000.0700000.0748000.0798000.0841000.0880000.0908000.0959000.01053000.01177000.01302000.01399000.01499000.01614000.01665000.01433000.01070000.01263000.01517000.01710000.01897000.02084000.02262000.02439000.02629000.02825000.0
Percentage of PropertyPlantAndEquipmentNet100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.40.30.30.30.50.50.50.40.71.31.21.21.23.52.52.11.61.01.11.33.73.73.73.63.63.715.6

None

us-gaap:OperatingLeaseRightOfUseAsset

us-gaap:OperatingLeaseRightOfUseAsset


None
Period End2020-06-302020-03-312019-12-31
Value2825000.02876000.03036000.0
Percentage of OperatingLeaseRightOfUseAsset100.0100.0100.0
Percentage of Assets1.71.51.3

None

us-gaap:LiabilitiesCurrent

us-gaap:LiabilitiesCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value2432424840424043346.8758.5067.2727.1912116.8258.1686.0895.2683.3743.2393.4273.3986.0935.6175.7535.433
Percentage of LiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets14.716.618.418.326.824.921.220.324.98.58.86.76.128.918.18.58.96.04.82.97.06.66.19.88.28.030.0

None

us-gaap:AccountsPayableCurrent

us-gaap:AccountsPayableCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value4828000.09309000.09100000.09536000.02485000.04943000.04371000.02638000.03692000.01156000.03829000.01187000.01865000.01688000.04738000.02387000.02931000.02348000.01965000.01263000.0711000.0938000.0515000.01715000.01191000.01586000.0676000.0
Percentage of AccountsPayableCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets2.94.73.93.61.72.92.31.22.61.43.91.11.63.97.43.03.22.31.81.11.51.80.92.71.72.23.7

None

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent

us-gaap:AccountsPayableAndAccruedLiabilitiesCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1317192012131314126.8758.5067.2727.1912116.8258.1686.0895.2683.3743.152.4641.9464.1492.5482.3361.958
Percentage of AccountsPayableAndAccruedLiabilitiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets8.38.98.47.88.57.87.16.69.08.58.86.76.128.918.18.58.96.04.82.96.84.83.56.73.73.310.8

None

us-gaap:OperatingLeaseLiabilityCurrent

us-gaap:OperatingLeaseLiabilityCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-30
Value1006000.0991000.0967000.0945000.0
Percentage of OperatingLeaseLiabilityCurrent100.0100.0100.0100.0
Percentage of Assets0.60.50.40.4

None

us-gaap:ContractWithCustomerLiabilityCurrent

us-gaap:ContractWithCustomerLiabilityCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value9.7681422262628262922
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.87.39.610.117.716.514.113.715.9

us-gaap:ContractWithCustomerLiabilityCurrent us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersByType

cara:LicenseAgreementWithViforFreseniusMedicalCareRenalPharmaLimited


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-30
Value9.7681422262628262922
Percentage of ContractWithCustomerLiabilityCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets5.87.39.610.117.716.514.113.715.9
Percentage of Assets cara:LicenseAgreementWithViforFreseniusMedicalCareRenalPharmaLimited0.00.00.00.00.00.00.00.00.0

None

us-gaap:OperatingLeaseLiabilityNoncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent


None
Period End2020-06-302020-03-312019-12-312019-09-30
Value2959000.03096000.03352000.03602000.0
Percentage of OperatingLeaseLiabilityNoncurrent100.0100.0100.0100.0
Percentage of Assets1.81.61.41.4

None

us-gaap:StockholdersEquity

us-gaap:StockholdersEquity


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value14016018621199114133149737286991092950718294105113424751556164-54.075-51.995-48.428-55.267-58.133-52.064
Percentage of StockholdersEquity100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets83.681.880.180.366.567.170.070.352.289.489.591.792.667.679.589.689.793.194.796.691.491.892.488.790.390.5-299.00.00.00.00.00.0

us-gaap:StockholdersEquity us-gaap:StatementEquityComponents

us-gaap:AccumulatedOtherComprehensiveIncome


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value0.635-0.0680.170.1530.1650.073-0.1140.013-0.057-0.114-0.070.04-0.0130.0240.0030.020.0410.004-0.035
Percentage of StockholdersEquity0.5-0.00.10.10.20.1-0.10.0-0.1-0.2-0.10.0-0.00.10.00.00.00.0-0.0
Percentage of Assets0.4-0.00.10.10.10.0-0.10.0-0.0-0.1-0.10.0-0.00.10.00.00.00.0-0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value5945905875834384304284233273093073053023002122112112102092091331321311311311308.3778.3647.3565.8541.2481.046
Percentage of StockholdersEquity422.2367.8314.5275.5440.6376.1320.3283.0448.0429.0354.0308.0277.31025.5419.6295.2255.7221.7199.9183.7313.2279.0255.2237.4212.8201.7-15.5-16.1-15.2-10.6-2.1-2.0
Percentage of Assets352.9300.8252.1221.3293.1252.5224.3199.0234.0383.6316.6282.4256.8693.2333.5264.4229.4206.3189.3177.4286.4256.1235.7210.6192.1182.446.30.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value0.0470.0470.0470.0460.040.0390.0390.0390.0340.0330.0330.0330.0330.0270.0270.0270.0270.0270.0270.0270.0230.0230.0230.0230.0230.0230.0040.0040.0040.0040.0030.003
Percentage of StockholdersEquity0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.10.00.00.00.00.00.10.00.00.00.00.0-0.0-0.0-0.0-0.0-0.0-0.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:CommonStock0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-312012-12-312011-12-31
Value-454.717-429.649-400.727-372.116-339.274-316.314-294.354-273.702-254.302-237.108-220.341-206.164-193.72-184.42-162.171-140.199-128.657-115.583-104.891-95.361-90.574-84.89-80.201-76.029-69.484-65.839-62.456-60.363-55.788-61.125-59.384-53.113
Percentage of StockholdersEquity-322.7-267.7-214.6-175.6-340.8-276.2-220.3-183.0-348.0-328.8-253.9-208.1-177.4-630.1-319.7-195.3-155.8-121.8-99.9-83.8-213.3-179.0-155.2-137.4-112.9-101.7115.5116.1115.2110.6102.2102.0
Percentage of Assets-269.7-219.0-172.0-141.1-226.7-185.4-154.3-128.7-181.8-294.1-227.1-190.8-164.2-425.9-254.1-174.9-139.8-113.3-94.6-80.9-195.0-164.3-143.4-121.9-101.9-92.0-345.40.00.00.00.00.0
Percentage of Assets us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:CommonStockValue

us-gaap:CommonStockValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value47000.047000.047000.046000.040000.039000.039000.039000.034000.033000.033000.033000.033000.027000.027000.027000.027000.027000.027000.027000.023000.023000.023000.023000.023000.023000.04000.0
Percentage of CommonStockValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.10.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:AdditionalPaidInCapitalCommonStock

us-gaap:AdditionalPaidInCapitalCommonStock


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value5945905875834384304284233273093073053023002122112112102092091331321318.377
Percentage of AdditionalPaidInCapitalCommonStock100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets352.9300.8252.1221.3293.1252.5224.3199.0234.0383.6316.6282.4256.8693.2333.5264.4229.4206.3189.3177.4286.4256.1235.746.3

None

us-gaap:RetainedEarningsAccumulatedDeficit

us-gaap:RetainedEarningsAccumulatedDeficit


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value-454720000.0-429650000.0-400730000.0-372120000.0-339270000.0-316310000.0-294350000.0-273700000.0-254300000.0-237110000.0-220340000.0-206160000.0-193720000.0-184420000.0-162170000.0-140200000.0-128660000.0-115580000.0-104890000.0-95361000.0-90574000.0-84890000.0-80201000.0-76029000.0-69484000.0-65839000.0-62456000.0
Percentage of RetainedEarningsAccumulatedDeficit100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets-269.7-219.0-172.0-141.1-226.7-185.4-154.3-128.7-181.8-294.1-227.1-190.8-164.2-425.9-254.1-174.9-139.8-113.3-94.6-80.9-195.0-164.3-143.4-121.9-101.9-92.0-345.4

None

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value635000.0-68000.0170000.0153000.0165000.073000.0-114000.013000.0-57000.0-114000.0-70000.040000.0-13000.024000.03000.020000.041000.04000.0-35000.00
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0
Percentage of Assets0.4-0.00.10.10.10.0-0.10.0-0.0-0.1-0.10.0-0.00.10.00.00.00.0-0.00.0

None

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value2.9932.8462.8352.6812.2342.0261.8192.0691.8711.7471.621.3181.1080.8290.7770.6980.4960.7070.6610.7010.4450.340.2220.4560.3530.0130.059
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-30
Value2.9932.8462.8352.6812.2342.0261.8192.0691.8711.7471.621.3181.1080.8290.7770.6980.4960.7070.6610.7010.4450.340.2220.4560.3530.0130.059
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Assets0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0
Percentage of Assets us-gaap:AdditionalPaidInCapital0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-27.652-38.303-31.166-25.637-24.896-27.526-24.361-20.49241-18.468-11.413-9.851
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-490.8-473.3-690.9-443.2-478.0-628.2-440.3-404.81427.30.00.00.0

None

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value673614-96.8812526-57.8315.454-51.136208.12612
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues1196.0456.7326.7-1674.7484.4602.4-1045.2107.7-1779.30.00.00.0

None

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.2010.0750.0281383.9740.2340.54493160.2630.1830.151
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues3.60.90.62391.876.35.39.81856.3558.10.00.00.0

None

us-gaap:NetCashProvidedByUsedInOperatingActivities

us-gaap:NetCashProvidedByUsedInOperatingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value-27.652-38.303-31.166-25.637-24.896-27.526-24.361-20.49241-18.468-11.413-9.851
Percentage of NetCashProvidedByUsedInOperatingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-490.8-473.3-690.9-443.2-478.0-628.2-440.3-404.81427.30.00.00.0

None

us-gaap:NetIncomeLoss

us-gaap:NetIncomeLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25068000.0-28922000.0-28611000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0-12444000.0-9300000.0-22204000.0-21971000.0-11542000.0-13075000.0-10692000.0-9530000.0-4787000.0-5684000.0-4689000.0-4172000.0-6545000.0-3645000.0-3383000.0-2093000.0-4575000.05337000.0-2632000.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-634.2-567.7-440.9-501.1-373.3-383.2-598.30.00.00.00.0-2437.30.00.0-16550.6-152742.90.0-196.2-650.3-958.9-456.5-581.8-379.7-1900.6-215.1-449.453.50.0

us-gaap:NetIncomeLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-25068000.0-28922000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0-12444000.0-9300000.0-22204000.0-21972000.0-11542000.0-13074000.0-10692000.0-9530000.0-4787000.0-5684000.0-4689000.0-4172000.0-6545000.0-3645000.0-3383000.0-2093000.0-4575000.05337000.0-2632000.0
Percentage of NetIncomeLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-567.7-440.9-501.1-373.3-383.2-598.30.00.00.00.0-2437.30.00.0-16549.4-152742.90.0-196.2-650.3-958.9-456.5-581.8-379.7-1900.6-215.1-449.453.50.0
Percentage of Revenues us-gaap:RetainedEarnings0.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0

None

us-gaap:ProfitLoss

us-gaap:ProfitLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value-25068000.0-28922000.0-28611000.0-32842000.0-22960000.0-21960000.0-20652000.0-19400000.0-17194000.0-16767000.0-14177000.0
Percentage of ProfitLoss100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues-444.9-357.4-634.2-567.7-440.9-501.1-373.3-383.2-598.30.00.0

None

us-gaap:DepreciationDepletionAndAmortization

us-gaap:DepreciationDepletionAndAmortization


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value48000.048000.048000.050000.050000.050000.052000.079000.0114000.0125000.0125000.0125000.0123000.0122000.0119000.097000.0519000.0730000.0259000.0194000.0193000.0193000.0193000.0197000.0196000.0197000.0197000.0197000.0197000.0198000.0
Percentage of DepreciationDepletionAndAmortization100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:ShareBasedCompensation

us-gaap:ShareBasedCompensation


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value4.6192.8463.3862.9334.0152.2343.7191.8192.0691.8711.7471.621.3181.1080.8290.7770.6980.4960.7070.6610.7010.4450.340.2221.162-0.3530.0130.0590.062-0.011
Percentage of ShareBasedCompensation100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:NetCashProvidedByUsedInInvestingActivities

us-gaap:NetCashProvidedByUsedInInvestingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value673614-96.8812526-57.8315.454-51.136208.12612
Percentage of NetCashProvidedByUsedInInvestingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues1196.0456.7326.7-1674.7484.4602.4-1045.2107.7-1779.30.00.00.0

None

us-gaap:NetCashProvidedByUsedInFinancingActivities

us-gaap:NetCashProvidedByUsedInFinancingActivities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-30
Value0.2010.0750.0281383.9740.2340.54493160.2630.1830.151
Percentage of NetCashProvidedByUsedInFinancingActivities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0
Percentage of Revenues3.60.90.62391.876.35.39.81856.3558.10.00.00.0

None

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber

cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value4964800.04930600.04450500.04575500.04705700.04925600.04004400.03780400.03871200.03933000.03492100.03492800.03118800.03154600.02548400.02299100.02256700.02214500.01658400.01541800.01583500.01294500.01022400.0490160.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312013-12-31
Value14.9614.9514.7314.514.3913.8613.3412.7612.4412.1811.7511.5811.1410.878.758.88.929.1710.279.659.238.778.161.34
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

None

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod

srt:Director, cara:June2020, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-30
Value36000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, cara:February2020, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-02-29
Value138000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName

srt:Director, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-312019-12-312019-06-04
Value12000.024000.0024000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod33.30.00.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, cara:TimeBasedRestrictedStockUnits, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-02-29
Value98000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod0.0

None

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312015-12-31
Value571718351914159718121013106.7751315
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cara:AmortizationExpenseComponentOfLeaseExpense

cara:AmortizationExpenseComponentOfLeaseExpense


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value165000.0160000.0148000.0145000.0
Percentage of AmortizationExpenseComponentOfLeaseExpense100.0100.0100.0100.0

cara:IncreaseDecreaseInOperatingLeaseLiabilities

cara:IncreaseDecreaseInOperatingLeaseLiabilities


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value-238000.0-232000.0-216000.0-211000.0
Percentage of IncreaseDecreaseInOperatingLeaseLiabilities100.0100.0100.0100.0

cara:PercentageOfResearchAndDevelopmentTaxCreditsExchangedForCash

cara:PercentageOfResearchAndDevelopmentTaxCreditsExchangedForCash


None
Period End2020-06-302020-03-312019-06-302019-03-31
Value00.6500.65
Percentage of PercentageOfResearchAndDevelopmentTaxCreditsExchangedForCash0.0100.00.0100.0

us-gaap:AccretionAmortizationOfDiscountsAndPremiumsInvestments

us-gaap:AccretionAmortizationOfDiscountsAndPremiumsInvestments


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value-31000.065000.0213000.0365000.0325000.0478000.0643000.0618000.0342000.0217000.0226000.0193000.0159000.04000.035000.057000.059000.067000.0
Percentage of AccretionAmortizationOfDiscountsAndPremiumsInvestments100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-31
Value39-1.269-16.4154.306-0.893-81.648785.9252.489-3.1042.3764.11-6.786
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss

us-gaap:DebtSecuritiesAvailableForSaleRealizedGainLoss


None
Period End2020-06-302018-12-312017-12-31
Value60000.027000.01000.0
Percentage of DebtSecuritiesAvailableForSaleRealizedGainLoss100.0100.0100.0

us-gaap:EarningsPerShareBasicAndDiluted

us-gaap:EarningsPerShareBasicAndDiluted


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value-0.54-0.62-0.61-0.74-0.58-0.56-0.52-0.51-0.52-0.51-0.43-0.38-0.29-0.81-0.81-0.42-0.48-0.39-0.35-0.19-0.25-0.21-0.18-0.29-0.16-0.22
Percentage of EarningsPerShareBasicAndDiluted100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities

us-gaap:IncreaseDecreaseInAccountsPayableAndAccruedLiabilities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value-3419000.0-2294000.0-915000.07814000.0-544000.0-312000.0-381000.01450000.05678000.0-1631000.01234000.082000.0-4791000.0448000.04709000.0-1060000.01796000.0820000.02151000.0-33000.01086000.0118000.0-1659000.01578000.0-158000.0227000.0-548000.0931000.0725000.0-386000.0
Percentage of IncreaseDecreaseInAccountsPayableAndAccruedLiabilities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

us-gaap:IncreaseDecreaseInContractWithCustomerLiability


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value-4.473-8.021-4.512-5.785-5.208-4.242-5.533-5.027
Percentage of IncreaseDecreaseInContractWithCustomerLiability100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable

us-gaap:IncreaseDecreaseInIncomeTaxesReceivable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-312013-09-302013-06-302013-03-31
Value182000.0122000.0-217000.049000.0235000.085000.0125000.066000.0-304000.046000.026000.0145000.02000.0-294000.0189000.055000.079000.0145000.0-66000.0200000.035000.015000.0111000.032000.011000.0-15000.03000.0020000.07000.0
Percentage of IncreaseDecreaseInIncomeTaxesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.0

us-gaap:IncreaseDecreaseInOtherReceivables

us-gaap:IncreaseDecreaseInOtherReceivables


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value-361000.0-124000.0187000.0179000.0-414000.093000.0733000.077000.032000.0-39000.026000.0-78000.0-808000.0896000.0-28000.0-136000.0123000.048000.0-2063000.0
Percentage of IncreaseDecreaseInOtherReceivables100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:IncreaseDecreaseInPrepaidExpense

us-gaap:IncreaseDecreaseInPrepaidExpense


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-03-312013-12-31
Value-564000.01825000.0307000.01142000.035000.02574000.0587000.0-1397000.02184000.01796000.0143000.0-443000.0-44000.0449000.0-3290000.01422000.0825000.0844000.0-207000.01346000.0-430000.0733000.0-148000.0377000.01608000.0
Percentage of IncreaseDecreaseInPrepaidExpense100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseCost us-gaap:CounterpartyName

us-gaap:OperatingLeaseCost

cara:StamfordOperatingLease


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value236000.0234000.0234000.0234000.0234000.0
Percentage of OperatingLeaseCost100.0100.0100.0100.0100.0

us-gaap:OperatingLeaseCost us-gaap:CounterpartyName, us-gaap:IncomeStatementLocation

cara:StamfordOperatingLease, us-gaap:GeneralAndAdministrativeExpense


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value71000.070000.070000.070000.070000.0
Percentage of OperatingLeaseCost30.129.929.929.929.9

cara:StamfordOperatingLease, us-gaap:ResearchAndDevelopmentExpense


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value165000.0164000.0164000.0164000.0164000.0
Percentage of OperatingLeaseCost69.970.170.170.170.1

us-gaap:OperatingLeasePayments us-gaap:CounterpartyName

us-gaap:OperatingLeasePayments

cara:StamfordOperatingLease


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-31
Value309000.0306000.0306000.0302000.0300000.0
Percentage of OperatingLeasePayments100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax

us-gaap:OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value703000.0-238000.017000.0-12000.092000.0187000.0-127000.070000.057000.0-44000.0-110000.053000.0-37000.021000.0-17000.0-21000.037000.039000.0
Percentage of OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax

us-gaap:OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value763000.0-238000.017000.0-12000.092000.0187000.0-100000.053000.057000.0-59000.0-109000.054000.0-37000.024000.0-6000.0-9000.037000.039000.0
Percentage of OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt

us-gaap:PaymentsToAcquireAvailableForSaleSecuritiesDebt


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-31
Value0.02145169185219940811611
Percentage of PaymentsToAcquireAvailableForSaleSecuritiesDebt0.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities

us-gaap:ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-31
Value425557724379892830261629191620171626
Percentage of ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt

us-gaap:ProceedsFromSaleOfAvailableForSaleSecuritiesDebt


None
Period End2020-06-302020-03-312019-06-302019-03-312018-12-312017-12-31
Value100.00.00.0513.025
Percentage of ProceedsFromSaleOfAvailableForSaleSecuritiesDebt100.00.00.00.0100.0100.0

us-gaap:ProceedsFromStockOptionsExercised

us-gaap:ProceedsFromStockOptionsExercised


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value201000.075000.055000.01843000.03974000.0234000.0558000.01888000.01485000.0263000.0183000.0151000.01216000.0149000.083000.00040000.039000.0288000.029000.06000.09000.090000.0
Percentage of ProceedsFromStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax

us-gaap:ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax


None
Period End2020-06-302020-03-312019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-30
Value60000.00027000.0-17000.00-15000.01000.01000.003000.011000.012000.0
Percentage of ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax100.00.00.0100.0100.00.0100.0100.0100.00.0100.0100.0100.0

us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross us-gaap:RelatedPartyTransaction

us-gaap:ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross

cara:MaruishiPharmaceuticalCompanyLimited


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value403000.065000.0000126000.0030000.0
Percentage of ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross100.0100.00.00.00.0100.00.0100.0

cara:ViforFreseniusMedicalCareRenalPharmaLimited


None
Period End2020-06-30
Value79000.0
Percentage of ResearchAndDevelopmentArrangementContractToPerformForOthersCostsIncurredGross19.6

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:GranteeStatus, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue

srt:Director, cara:June2020, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-04
Value15.62
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, cara:February2020, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-02-29
Value16.36
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, cara:TimeBasedRestrictedStockUnits, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-02-29
Value16.36
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod

srt:Director, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementNonemployee


None
Period End2020-03-31
Value0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod0.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-04-302019-12-312019-05-31
Value30000.065834.036666.074166.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod0.00.00.00.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.7480.747100.00010.73780.751900.8760.9280.0120.8170.8330.8070.0520.7190.7260.6970.0030.00100.670.003000.71
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum100.0100.00.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.0100.0100.00.00.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.73730.7372-0.0070.7180.73060.742900.8260.85700.81400.753000.6930.67800-0.010.65-0.0010-0.020.67
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum100.0100.0100.0100.0100.0100.00.0100.0100.00.0100.00.0100.00.00.0100.0100.00.00.0100.0100.0100.00.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.00540.0157000.02360.02620.0010.02990.02940.027100.01970.01880.02570.00140.01190.01790.0159000.01890.017000.01990.0272
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum100.0100.00.00.0100.0100.0100.0100.0100.0100.00.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.00.00.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value0.00420.0054-0.0007-0.00330.01950.025400.02730.02850.025100.01870.01850.02070-0.00040.01230.014000.01870.0143-0.001600.0180.0219
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum100.0100.0100.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.0100.0100.0100.00.00.0100.0100.0100.00.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross

cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-31
Value147000.0673350.020000.0241000.0957000.0300000.0165000.0136500.0596000.075000.0415000.090000.0748500.0281000.075000.0112000.0610000.0145000.025000.0309000.0295000.0230000.040000.0227000.0387000.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-30
Value10.2310.590.3215.2913.0710.830.7414.5110.4910.43-0.1510.013.5312.270.473.923.55
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage us-gaap:GranteeStatus, us-gaap:PlanName, us-gaap:Vesting

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage

us-gaap:ShareBasedPaymentArrangementEmployee, cara:TwoThousandNineteenInducementPlan, us-gaap:ShareBasedCompensationAwardTrancheOne


None
Period End2020-06-302020-03-31
Value00.25
Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage0.0100.0

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage us-gaap:TitleOfIndividual, us-gaap:PlanName, us-gaap:Vesting

cara:EmployeeAndNonemployeeConsultants, cara:TwoThousandAndFourteenEquityIncentivePlan, us-gaap:ShareBasedCompensationAwardTrancheOne


None
Period End2020-06-302020-03-31
Value00.25
Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage0.0100.0

us-gaap:StockIssuedDuringPeriodSharesNewIssues us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

us-gaap:StockIssuedDuringPeriodSharesNewIssues

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-04-30
Value30000.065834.0
Percentage of StockIssuedDuringPeriodSharesNewIssues100.0100.0

us-gaap:StockIssuedDuringPeriodSharesRestrictedStockAwardGross us-gaap:StatementEquityComponents

us-gaap:StockIssuedDuringPeriodSharesRestrictedStockAwardGross

us-gaap:CommonStock


None
Period End2020-06-302019-12-312019-05-312019-06-30
Value119830.036666.074166.074166.0
Percentage of StockIssuedDuringPeriodSharesRestrictedStockAwardGross100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodSharesRestrictedStockAwardGross us-gaap:TitleOfIndividual, us-gaap:StatementEquityComponents

srt:Director, us-gaap:CommonStock


None
Period End2020-06-30
Value24000.0
Percentage of StockIssuedDuringPeriodSharesRestrictedStockAwardGross20.0

srt:ExecutiveOfficer, us-gaap:CommonStock


None
Period End2020-06-302019-05-31
Value95834.074166.0
Percentage of StockIssuedDuringPeriodSharesRestrictedStockAwardGross80.0100.0

us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised us-gaap:PlanName

us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised

cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-31
Value16846.07500.0150270.0378710.017291.074252.0155300.0184440.037688.053770.041000.0125830.027291.014000.00028000.023280.066708.012000.022880.0
Percentage of StockIssuedDuringPeriodSharesStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodSharesStockOptionsExercised us-gaap:StatementEquityComponents

us-gaap:CommonStock


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value16846.07500.0150270.0378710.017291.074252.0155300.0184440.037688.053770.041000.0125830.027291.014000.00028000.023280.066708.012000.022880.012000.0133800.0
Percentage of StockIssuedDuringPeriodSharesStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.00.00.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross


None
Period End2020-06-302019-06-30
Value1625000.01235000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0

us-gaap:StockIssuedDuringPeriodValueRestrictedStockAwardGross us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302019-06-30
Value1625000.01235000.0
Percentage of StockIssuedDuringPeriodValueRestrictedStockAwardGross100.0100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value201000.075000.01843000.03975000.0234000.0558000.01888000.01485000.0263000.0183000.0151000.01216000.0149000.083000.00040000.039000.0288000.029000.06000.09000.090000.0
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital


None
Period End2020-06-302020-03-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-30
Value201000.075000.01843000.03974000.0234000.0558000.01888000.01485000.0263000.0183000.0151000.01215000.0149000.083000.00040000.039000.0288000.029000.06000.09000.090000.0
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.099.9100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0

cara:AccruedResearchProjects

cara:AccruedResearchProjects


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value5864000.05699000.06637000.07748000.07795000.06446000.06079000.08978000.06941000.04387000.02356000.03758000.03531000.08861000.04352000.01817000.02779000.02495000.01542000.0969000.01552000.0841000.0549000.01476000.0755000.0432000.0405000.0
Percentage of AccruedResearchProjects100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cara:AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions

cara:AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302015-12-31
Value42.068.081.084.058.073.084.031.026.027.031.028.033.024.034.041.038.023.0
Percentage of AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

cara:AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-31
Value28.042.0
Percentage of AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions66.761.8

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-31
Value6.0
Percentage of AvailableForSaleSecuritiesQualitativeDisclosureNumberOfPositions8.8

cara:PrepaidResearchAndDevelopmentExpenses

cara:PrepaidResearchAndDevelopmentExpenses


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value8499000.08707000.08498000.07751000.06461000.06121000.04377000.03466000.04923000.02532000.01287000.0984000.01321000.01109000.01256000.04363000.02874000.01810000.01500000.01627000.035000.0741000.0177000.0639000.01298000.0549000.0262000.0
Percentage of PrepaidResearchAndDevelopmentExpenses100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedEmployeeBenefitsCurrent

us-gaap:AccruedEmployeeBenefitsCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value2554000.01627000.03293000.02731000.01959000.01200000.02370000.02011000.01478000.0954000.01864000.01496000.01119000.0681000.01514000.01177000.0835000.0646000.01204000.0708000.0543000.0350000.0504000.0488000.0239000.0104000.083000.0
Percentage of AccruedEmployeeBenefitsCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AccruedProfessionalFeesCurrent

us-gaap:AccruedProfessionalFeesCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value706000.0736000.0635000.0566000.0527000.0721000.0802000.0253000.0356000.0257000.0384000.0473000.0323000.0688000.0163000.0373000.0342000.0398000.0371000.0348000.0303000.0278000.0266000.0434000.0227000.0192000.0739000.0
Percentage of AccruedProfessionalFeesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:AssetsFairValueDisclosure

us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value5717183515971813106.775136.8955.0149.3911511343475359636713
Percentage of AssetsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value9616219921416710911491103314665818891
Percentage of AssetsFairValueDisclosure167.5932.91068.0610.51058.0112.2614.7687.7946.4465.0340.6957.11619.8940.5580.0

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value1531802182491361561832061327593104113385972869710753
Percentage of AssetsFairValueDisclosure267.51032.91168.0710.50.00.01158.0212.2714.70.00.0787.71046.4565.0440.61057.11719.81040.5680.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302016-12-31
Value638000.0393000.0197000.0203000.0171000.085000.05000.029000.03000.012000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax us-gaap:InvestmentType

us-gaap:CommercialPaper


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-09-302018-06-302016-12-31
Value24000.026000.027000.019000.014000.06000.01000.03000.03000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax3.86.613.79.48.27.13.4100.025.0

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-30
Value416000.079000.0125000.0145000.0109000.056000.05000.01000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax65.220.163.571.463.765.9100.03.4

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312016-12-31
Value18000.039000.014000.012000.016000.07000.01000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax2.89.97.15.99.48.28.3

us-gaap:USTreasurySecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value180000.0249000.031000.027000.032000.016000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax28.263.415.713.318.718.8

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3000.0461000.027000.050000.06000.012000.0119000.016000.060000.0114000.070000.09000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3000.0460000.023000.027000.06000.010000.094000.05000.01000.011000.012000.06000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax100.099.885.254.0100.083.379.031.21.79.617.166.7

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-312019-12-312019-09-302018-12-312018-03-312017-12-31
Value1000.01000.011000.01000.03000.05000.0
Percentage of AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax0.23.722.00.82.67.1

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value95162199214116141167109114628346
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleDebtSecuritiesAmortizedCostBasis us-gaap:InvestmentType

us-gaap:CommercialPaper


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value133138652338504136201915
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis13.919.619.330.520.126.930.037.932.132.423.532.9

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value6293115108626975106.7359.3511516
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis65.057.558.050.553.549.345.310.05.914.919.136.1

us-gaap:MunicipalBonds


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value3.53.53.55.55.55.54.0
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis3.72.11.82.64.73.92.4

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value3.4991725221212172.5921.0963.7997.7993.501
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis3.710.812.910.510.68.810.62.41.06.19.47.6

us-gaap:USTreasurySecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302016-12-31
Value131616121215192.9961.4952.523
Percentage of AvailableForSaleDebtSecuritiesAmortizedCostBasis13.79.98.06.011.111.211.62.71.35.5

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value22596355202121
Percentage of AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value22596355202121
Percentage of AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value7210313615896120146574633434860243747494649
Percentage of AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue

us-gaap:AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-31
Value7310313615896120146574633434860243747494649
Percentage of AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities

us-gaap:AvailableForSaleSecuritiesDebtSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value9616219921411714116783
Percentage of AvailableForSaleSecuritiesDebtSecurities100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:CommercialPaper, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value1331386550
Percentage of AvailableForSaleSecuritiesDebtSecurities13.919.619.330.530.0

us-gaap:USTreasurySecurities, us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value1316161219
Percentage of AvailableForSaleSecuritiesDebtSecurities13.810.08.06.011.7

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:CommercialPaper, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value13313865233850
Percentage of AvailableForSaleSecuritiesDebtSecurities13.919.619.330.520.126.830.0

us-gaap:USTreasurySecurities, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value13161612131519
Percentage of AvailableForSaleSecuritiesDebtSecurities13.810.08.06.011.111.211.7

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value629311510875
Percentage of AvailableForSaleSecuritiesDebtSecurities65.057.358.050.545.3

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:MunicipalBonds


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value3.53.53.55.54.0
Percentage of AvailableForSaleSecuritiesDebtSecurities3.62.21.82.62.4

us-gaap:FairValueInputsLevel2, us-gaap:FairValueMeasurementsRecurring, us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value3.51717252217
Percentage of AvailableForSaleSecuritiesDebtSecurities3.710.812.910.510.6

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:FairValueByMeasurementFrequency, us-gaap:InvestmentType

us-gaap:FairValueMeasurementsRecurring, us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312017-12-31
Value62931151087515
Percentage of AvailableForSaleSecuritiesDebtSecurities65.057.358.050.545.319.1

us-gaap:FairValueMeasurementsRecurring, us-gaap:MunicipalBonds


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-31
Value3.53.53.55.54.0
Percentage of AvailableForSaleSecuritiesDebtSecurities3.62.21.82.62.4

us-gaap:FairValueMeasurementsRecurring, us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312017-12-31
Value3.517172522177.794
Percentage of AvailableForSaleSecuritiesDebtSecurities3.710.812.910.510.69.4

us-gaap:AvailableForSaleSecuritiesDebtSecurities us-gaap:InvestmentType

us-gaap:CommercialPaper


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value1331386523385019
Percentage of AvailableForSaleSecuritiesDebtSecurities13.919.619.330.520.126.830.023.5

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value629311510862697515
Percentage of AvailableForSaleSecuritiesDebtSecurities65.057.358.050.553.549.345.319.1

us-gaap:MunicipalBonds


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value3.53.53.55.55.55.54.0
Percentage of AvailableForSaleSecuritiesDebtSecurities3.62.21.82.64.73.92.4

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value3.5171725221212177.794
Percentage of AvailableForSaleSecuritiesDebtSecurities3.710.812.910.510.68.810.69.4

us-gaap:USTreasurySecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value13161612131519
Percentage of AvailableForSaleSecuritiesDebtSecurities13.810.08.06.011.111.211.7

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesCurrent

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312016-12-31
Value7310313615896120146109114628346
Percentage of AvailableForSaleSecuritiesDebtSecuritiesCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesNoncurrent

us-gaap:AvailableForSaleSecuritiesDebtSecuritiesNoncurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-31
Value22596355202121
Percentage of AvailableForSaleSecuritiesDebtSecuritiesNoncurrent100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:CashAndCashEquivalentsFairValueDisclosure

us-gaap:MoneyMarketFunds, us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value56171834159617119.4165.306125.4263.5457.9221511042465258626712
Percentage of CashAndCashEquivalentsFairValueDisclosure100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:MoneyMarketFunds, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312014-12-31
Value561718341814159617119.388119.4165.306125.4263.5457.9221552
Percentage of CashAndCashEquivalentsFairValueDisclosure100.0100.0100.0100.00.00.0100.0100.0100.00.00.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value5.5076738484.7563013282
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value5.5076328274.756147115
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months100.093.774.657.4100.048.253.719.2

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-312019-12-312019-09-302018-12-312017-12-31
Value4.2482.45.4875.5967.794
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months6.36.211.44.29.4

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value3000.0461000.027000.050000.06000.012000.0119000.070000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value3000.0460000.023000.027000.06000.010000.094000.012000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss100.099.885.254.0100.083.379.017.1

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-312019-12-312019-09-302018-12-312017-12-31
Value1000.01000.011000.01000.05000.0
Percentage of DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss0.23.722.00.87.1

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value5.5076738484.7563013282
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPosition us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value5.5076328274.756147115
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition100.093.774.657.4100.048.253.719.2

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-312019-12-312019-09-302018-12-312017-12-31
Value4.2482.45.4875.5967.794
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPosition6.36.211.44.29.4

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value3000.0461000.027000.050000.06000.012000.0119000.070000.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312017-12-31
Value3000.0460000.023000.027000.06000.010000.094000.012000.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss100.099.885.254.0100.083.379.017.1

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-312019-12-312019-09-302018-12-312017-12-31
Value1000.01000.011000.01000.05000.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss0.23.722.00.87.1

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value2.029.016.023.06.018.069.026.030.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions us-gaap:InvestmentType

us-gaap:CorporateBondSecurities


None
Period End2020-06-302020-03-31
Value2.028.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions100.096.6

us-gaap:USGovernmentCorporationsAndAgenciesSecurities


None
Period End2020-03-31
Value1.0
Percentage of DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions3.4

us-gaap:IncomeTaxesReceivable

us-gaap:IncomeTaxesReceivable


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1120000.0938000.0816000.01033000.0984000.0749000.0664000.0539000.0473000.0777000.0731000.0705000.0560000.0558000.0852000.0663000.0608000.0529000.0384000.0450000.0250000.0215000.0200000.089000.057000.046000.061000.0
Percentage of IncomeTaxesReceivable100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:InterestReceivableCurrent

us-gaap:InterestReceivableCurrent


None
Period End2020-06-302020-03-312019-12-31
Value401000.0847000.0971000.0
Percentage of InterestReceivableCurrent100.0100.0100.0

us-gaap:LesseeOperatingLeaseDiscountRate us-gaap:PropertyPlantAndEquipmentByType

us-gaap:LesseeOperatingLeaseDiscountRate

cara:NewStamfordLease


None
Period End2020-05-31
Value0.07
Percentage of LesseeOperatingLeaseDiscountRate100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue


None
Period End2020-06-30
Value4488000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue us-gaap:PropertyPlantAndEquipmentByType

cara:NewStamfordLease


None
Period End2020-05-31
Value2000000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue0.0

us-gaap:OperatingLeaseLiability

us-gaap:OperatingLeaseLiability


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-31
Value3965000.04087000.04319000.04547000.04772000.04988000.0
Percentage of OperatingLeaseLiability100.0100.0100.0100.0100.0100.0

us-gaap:OtherPrepaidExpenseCurrent

us-gaap:OtherPrepaidExpenseCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value455000.0276000.0184000.0324000.0380000.0536000.0183000.0247000.0213000.0193000.0224000.0162000.0148000.0188000.0162000.0130000.064000.092000.035000.050000.081000.060000.018000.012000.09000.013000.011000.0
Percentage of OtherPrepaidExpenseCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:OtherReceivablesNetCurrent

us-gaap:OtherReceivablesNetCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302017-12-31
Value486000.0847000.0971000.0784000.0605000.01019000.0926000.0193000.0123000.0
Percentage of OtherReceivablesNetCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PrepaidExpenseCurrent

us-gaap:PrepaidExpenseCurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-03-312014-12-312014-09-302013-12-31
Value10108.8638.5567.5127.5774.8054.2185.6153.4311.6351.4921.9341.9791.534.823.3982.5731.7291.9711.420.2870.9282.14
Percentage of PrepaidExpenseCurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:PrepaidInsurance

us-gaap:PrepaidInsurance


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302017-03-312016-12-312016-09-302016-06-302016-03-312015-12-312015-09-302015-06-302015-03-312014-12-312014-09-302014-06-302014-03-312013-12-31
Value1170000.01705000.0181000.0481000.0671000.0920000.0245000.0505000.0479000.0706000.0124000.0346000.0465000.0682000.0112000.0327000.0460000.0671000.098000.0294000.0423000.0619000.092000.0277000.0399000.0580000.034000.0
Percentage of PrepaidInsurance100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent us-gaap:FairValueByAssetClass, us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementFrequency

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent

us-gaap:MoneyMarketFunds, us-gaap:FairValueInputsLevel1, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302018-12-312018-09-302018-06-302017-09-302017-06-302016-12-31
Value408000.0408000.0408000.0408000.0769000.0769000.0769000.01469000.01469000.01469000.0
Percentage of RestrictedCashAndCashEquivalentsNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedCashAndCashEquivalentsNoncurrent us-gaap:FairValueByAssetClass, us-gaap:FairValueByMeasurementFrequency

us-gaap:MoneyMarketFunds, us-gaap:FairValueMeasurementsRecurring


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302018-03-312017-12-312017-09-302017-06-302016-12-31
Value408000.0408000.0408000.0408000.0769000.0769000.0769000.0769000.0769000.0769000.0769000.01469000.01469000.01469000.0
Percentage of RestrictedCashAndCashEquivalentsNoncurrent100.0100.0100.0100.00.00.0100.0100.0100.00.00.0100.0100.0100.0

us-gaap:RestrictedCashNoncurrent

us-gaap:RestrictedCashNoncurrent


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302019-03-312018-12-312018-09-302018-06-302017-12-31
Value408000.0408000.0408000.0408000.0408000.0408000.0408000.0408000.0408000.0769000.0
Percentage of RestrictedCashNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:RestrictedCashNoncurrent us-gaap:RestrictedCashAndCashEquivalentsCashAndCashEquivalents

cara:MoneyMarketFundForStamfordLease


None
Period End2020-06-302020-03-312019-12-312019-09-302019-06-302018-12-312018-09-302017-12-31
Value408000.0408000.0408000.0408000.0408000.0408000.0408000.0769000.0
Percentage of RestrictedCashNoncurrent100.0100.0100.0100.0100.0100.0100.0100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber us-gaap:TitleOfIndividual, us-gaap:AwardDate, us-gaap:AwardType, us-gaap:PlanName

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber

srt:ExecutiveOfficer, cara:March2019, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-03-31
Value95834.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:GranteeStatus

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, us-gaap:ShareBasedPaymentArrangementEmployee


None
Period End2020-06-302020-03-31
Value236000.0331830.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber0.0346.3

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName

srt:ExecutiveOfficer, us-gaap:RestrictedStockUnitsRSU, cara:TwoThousandAndFourteenEquityIncentivePlan


None
Period End2020-06-30
Value0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber0.0

Line plots across dimensions of each concept


us-gaap:RevenueFromContractWithCustomerExcludingAssessedTax
us-gaap:ProductOrService
(None,)
None
us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:IncomeStatementLocation
(None,)
None
us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:AwardType, us-gaap:IncomeStatementLocation
('us-gaap:RestrictedStockUnitsRSU', None)
None
us-gaap:AllocatedShareBasedCompensationExpense
us-gaap:TitleOfIndividual, us-gaap:AwardType, us-gaap:PlanName
('srt:ExecutiveOfficer', None, 'cara:TwoThousandAndFourteenEquityIncentivePlan')
None
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
None
us-gaap:StockholdersEquity
us-gaap:StatementEquityComponents
(None,)
None