XML 107 R93.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Commitments and Contingencies - Additional Information (Detail) $ in Thousands |  |  |  |  |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 01, 2024 USD ($) | Sep. 26, 2024 USD ($) | Jul. 28, 2023 USD ($) | May 11, 2023 USD ($) | Aug. 31, 2019 USD ($) | Jul. 31, 2021 | Jul. 31, 2019 agreement | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Sep. 25, 2024 USD ($)
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Research and development |  |  |  |  |  |  |  | $ 32,805 | $ 108,510 | $ 91,879 |
Operating Lease, renewable term |  |  |  | 5 years |  |  |  |  |  |  |
Operating lease right-of-use assets |  |  |  |  |  |  |  |  | 4,864 |  |
Cash payment relating to operating leases |  |  |  |  |  |  |  | 4,363 | $ 1,992 |  |
New Corporate Headquarters Office Space [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Lease, annual fixed rent |  |  |  | $ 1,300 |  |  |  |  |  |  |
Lease, fixed rent, annual increase, percent |  |  |  | 2.50% |  |  |  |  |  |  |
Option to extend |  |  |  | true |  |  |  |  |  |  |
Lessee, operating lease, discount rate, basis spread on variable rate |  |  |  | 7.75% |  |  |  |  | 7.75% |  |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] |  |  |  | us-gaap:SecuredOvernightFinancingRateSofrMember |  |  |  |  |  |  |
Discount rate - operating leases |  |  |  |  |  |  |  |  | 12.83% |  |
Operating lease liabilities |  |  | $ 6,672 |  |  |  |  |  |  |  |
Lessee, operating lease, incentives |  |  | 2,900 |  |  |  |  |  |  |  |
Operating lease right-of-use assets |  |  | $ 6,779 |  |  |  |  |  |  |  |
Lease incentives reimbursed |  |  |  |  |  |  |  | 2,094 | $ 808 |  |
Lease incentives remaining to be reimbursed |  |  |  |  |  |  |  | 0 |  |  |
Operating Lease, expense |  |  |  |  |  |  |  | 766 | $ 524 |  |
Lessee, operating lease, discount rate, variable rate basis, floor |  |  |  | 2.75% |  |  |  |  | 2.75% |  |
New Corporate Headquarters Office Space [Member] | Research and Development [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating Lease, expense |  |  |  |  |  |  |  | 368 | $ 367 |  |
New Corporate Headquarters Office Space [Member] | General and Administrative [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating Lease, expense |  |  |  |  |  |  |  | 398 | 157 |  |
Assignment of New Lease |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating lease, cash lease payments |  | $ 3,238 |  |  |  |  |  |  |  |  |
Operating lease, release payments |  | 1,125 |  |  |  |  |  |  |  |  |
Operating lease, non-cash lease payments | $ 3,417 |  |  |  |  |  |  |  |  |  |
Operating lease, initial direct costs capitalized |  | 577 |  |  |  |  |  |  |  |  |
Operating lease liability - current |  | 3,417 |  |  |  |  |  |  |  |  | $ 7,780
Cash payment relating to operating leases |  | $ 4,363 |  |  |  |  |  |  |  |  |
Impairment charge in ROU asset |  |  |  |  |  |  |  | 4,274 |  |  |
Future non-cash lease payments |  |  |  |  |  |  |  | 0 |  |  |
Old Stamford Operating Lease [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating lease cost |  |  |  |  |  |  |  |  | 1,624 | 1,624 |
Old Stamford Operating Lease [Member] | Research and Development [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating lease cost |  |  |  |  |  |  |  |  | 1,137 | 1,137 |
Old Stamford Operating Lease [Member] | General and Administrative [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Operating lease cost |  |  |  |  |  |  |  |  | 487 | 487 |
Patheon [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Reduced demand payment for manufacturing commitments |  |  |  |  |  |  |  |  | 1,700 |  |
New Stamford Lease [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Letter of credit amount outstanding |  |  |  |  |  |  |  |  | 1,500 |  |
Non-Exclusive License Agreement [Member] | Enteris Biopharma, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Upfront fee |  |  |  |  | $ 8,000 |  |  |  |  |  |
Payment of milestone payment |  |  |  |  |  |  |  | $ 0 | $ 0 | 5,000 |
Research and development |  |  |  |  |  |  |  |  |  | $ 5,000 |
License agreement expiration period, first commercial sale |  |  |  |  | 10 years |  |  |  |  |  |
Upfront fee payment, cash |  |  |  |  | $ 4,000 |  |  |  |  |  |
Upfront fee payment, stock |  |  |  |  | $ 4,000 |  |  |  |  |  |
Agreement termination period for material breach |  |  |  |  | 60 days |  |  |  |  |  |
Agreement termination period for material breach of a payment obligation |  |  |  |  | 30 days |  |  |  |  |  |
Agreement termination period for challenged patent rights |  |  |  |  | 30 days |  |  |  |  |  |
Agreement termination period prior to first regulatory approval |  |  |  |  | 30 days |  |  |  |  |  |
Agreement termination period after first regulatory approval |  |  |  |  | 60 days |  |  |  |  |  |
MSA [Member] | Patheon and Patheon Manufacturing Services LLC [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Number of related product agreements | agreement |  |  |  |  |  |  | 2 |  |  |  |
MSA [Member] | Patheon [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Agreement renewal term |  |  |  |  |  |  | 2 years |  |  |  |
Agreement initial term, expiration date |  |  |  |  |  |  | Dec. 31, 2024 |  |  |  |
Agreement expiration date |  |  |  |  |  |  | Dec. 31, 2026 |  |  |  |
API Commercial Supply Agreement - PPL [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Agreement renewal term |  |  |  |  |  | 5 years |  |  |  |  |
MSA or Product Agreement [Member] | Patheon [Member] |  |  |  |  |  |  |  |  |  |  |
Other Commitments [Line Items] |  |  |  |  |  |  |  |  |  |  |
Agreement initial term, expiration date |  |  |  |  |  |  | Either party may terminate the MSA or a Product Agreement upon written notice if the other party (1) has failed to remedy a material breach within a specified time or (2) is declared insolvent or bankrupt, voluntarily files a petition of bankruptcy or assigns such agreement for the benefit of creditors. The Company may terminate a Product Agreement (a) upon 90 days’ prior written notice if any governmental agency takes any action that prevents the Company from selling the relevant product in the relevant territory, (b) upon six months’ prior written notice if it does not intend to order manufacturing services due to a product’s discontinuance in the market, or (c) upon 90 days’ prior written notice if it determines that the manufacture or supply of a product likely infringes third-party rights. Patheon may terminate the MSA or a Product Agreement (i) upon six months’ prior written notice if the Company assigns such agreement to an assignee that is unacceptable to Patheon for certain reasons, or (ii) upon 30 days’ prior written notice if, after the first year of commercial sales, the Company forecasts zero volume for 12 months. |  |  |  |
Termination notice effective period upon government agency restrictions |  |  |  |  |  |  | 90 days |  |  |  |
Termination notice effective period upon discontinuance in the market |  |  |  |  |  |  | 6 months |  |  |  |
Termination notice period if likely infringes on third-party rights |  |  |  |  |  |  | 90 days |  |  |  |
Termination notice period if assignee is unacceptable |  |  |  |  |  |  | 6 months |  |  |  |
Termination notice period if zero volume is forecasted after first year of commercial sales |  |  |  |  |  |  | 30 days |  |  |  |

X
- Definition Agreement expiration date. + References No definition available. + Details
Name: | cara_AgreementExpirationDate
Namespace Prefix: | cara_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Agreement initial term expiration date. + References No definition available. + Details
Name: | cara_AgreementInitialTermExpirationDate
Namespace Prefix: | cara_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Agreement renewal term. + References No definition available. + Details
Name: | cara_AgreementRenewalTerm
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Agreement termination notice description. + References No definition available. + Details
Name: | cara_AgreementTerminationNoticeDescription
Namespace Prefix: | cara_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The notice period to terminate the agreement upon a material breach. + References No definition available. + Details
Name: | cara_AgreementTerminationNoticePeriod
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The notice period to terminate the agreement after the first regulatory approval. + References No definition available. + Details
Name: | cara_AgreementTerminationNoticePeriodAfterFirstRegulatoryApproval
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The notice period to terminate the agreement upon the challenge of licensed patent rights. + References No definition available. + Details
Name: | cara_AgreementTerminationNoticePeriodChallengedPatentRights
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The notice period to terminate the agreement prior to the first regulatory approval. + References No definition available. + Details
Name: | cara_AgreementTerminationNoticePeriodPriorToFirstRegulatoryApproval
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The notice period to terminate the agreement upon a material breach of a payment obligation. + References No definition available. + Details
Name: | cara_AgreementTerminationPaymentObligationMaterialBreachNoticePeriod
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of annual fixed rent payable under lease. + References No definition available. + Details
Name: | cara_LeaseAnnualFixedRent
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percent of annual increase in fixed rent payments under lease. + References No definition available. + Details
Name: | cara_LeaseFixedRentAnnualIncreasePercent
Namespace Prefix: | cara_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of lease incentives reimbursed. + References No definition available. + Details
Name: | cara_LeaseIncentivesReimbursed
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of lease incentives remaining to be reimbursed. + References No definition available. + Details
Name: | cara_LeaseIncentivesRemainingToBeReimbursed
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage points added to the reference rate to determine present value of operating lease payments. + References No definition available. + Details
Name: | cara_LesseeOperatingLeaseDiscountRateBasisSpreadOnVariableRate
Namespace Prefix: | cara_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Floor rate on variable interest rate to calculate present value of operating lease payments. + References No definition available. + Details
Name: | cara_LesseeOperatingLeaseDiscountRateVariableRateBasisFloor
Namespace Prefix: | cara_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of payments or reimbursements from lessor to or on behalf of the lessee. + References No definition available. + Details
Name: | cara_LesseeOperatingLeaseIncentives
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The period over which the license agreement will expire from the date first commercial sale of the product. + References No definition available. + Details
Name: | cara_LicenseAgreementExpirationPeriodFirstCommercialSale
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of manufacturing commitments. + References No definition available. + Details
Name: | cara_ManufacturingCommitments
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The number of related product agreements. + References No definition available. + Details
Name: | cara_NumberOfRelatedProductAgreements
Namespace Prefix: | cara_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of cash lease payments for operating lease. + References No definition available. + Details
Name: | cara_OperatingLeaseCashLeasePayments
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of initial direct costs capitalized for operating lease right-of-use assets. + References No definition available. + Details
Name: | cara_OperatingLeaseInitialDirectCostsCapitalized
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of non-cash lease payments for operating lease. + References No definition available. + Details
Name: | cara_OperatingLeaseNonCashLeasePayments
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of release payments for operating lease. + References No definition available. + Details
Name: | cara_OperatingLeaseReleasePayments
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of milestone payments made during the period. + References No definition available. + Details
Name: | cara_PaymentOfMilestonePayment
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The termination notice period if it is determined that the manufacture or supply of a product likely infringes third-party rights. + References No definition available. + Details
Name: | cara_ProductAgreementTerminationNoticePeriodForInfringementOnThirdPartyRights
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The product agreement termination notice period if, after the first year of commercial sales, zero volume for 12 months is forecasted. + References No definition available. + Details
Name: | cara_ProductAgreementTerminationNoticePeriodForecastedZeroVolumeAfterFirstYear
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The termination notice period if any government agency takes any action that prevents selling the relevant product in the relevant territory. + References No definition available. + Details
Name: | cara_ProductAgreementTerminationNoticePeriodGovernmentAgencyRestriction
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The product agreement termination period if the agreement is assigned to an assignee that is unacceptable. + References No definition available. + Details
Name: | cara_ProductAgreementTerminationNoticePeriodUnacceptableAssignee
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The termination notice period if the product is discontinued in the market. + References No definition available. + Details
Name: | cara_ProductAgreementTerminationNoticePeriodUponProductDiscontinuation
Namespace Prefix: | cara_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of upfront fee paid in cash. + References No definition available. + Details
Name: | cara_UpfrontFeeCash
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of upfront fee payable. + References No definition available. + Details
Name: | cara_UpfrontFeePayable
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of upfront payment in the form of shares. + References No definition available. + Details
Name: | cara_UpfrontFeePaymentStock
Namespace Prefix: | cara_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Indicates type of variable interest rate on debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 470 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477734/942-470-50-3 + Details
Name: | us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration
Namespace Prefix: | us-gaap_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate used by lessee to determine present value of operating lease payments. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-3 + Details
Name: | us-gaap_LesseeOperatingLeaseDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Indicates (true false) whether lessee has option to extend operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-3 + Details
Name: | us-gaap_LesseeOperatingLeaseExistenceOfOptionToExtend
Namespace Prefix: | us-gaap_
Data Type: | xbrli:booleanItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of lessee's undiscounted obligation for lease payment for operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-6 + Details
Name: | us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-3 + Details
Name: | us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 53 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479589/842-20-55-53 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-4 + Details
Name: | us-gaap_OperatingLeaseCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of operating lease expense. Excludes sublease income. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-4 + Details
Name: | us-gaap_OperatingLeaseExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of loss from impairment of right-of-use asset from operating lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 25 -Paragraph 6 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479365/842-20-25-6 + Details
Name: | us-gaap_OperatingLeaseImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-1 + Details
Name: | us-gaap_OperatingLeaseLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-1 + Details
Name: | us-gaap_OperatingLeaseLiabilityCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (g)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478964/842-20-50-4 + Details
Name: | us-gaap_OperatingLeasePayments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of lessee's right to use underlying asset under operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 842 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479041/842-20-45-1 + Details
Name: | us-gaap_OperatingLeaseRightOfUseAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_OtherCommitmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for research and development. Includes, but is not limited to, cost for computer software product to be sold, leased, or otherwise marketed and writeoff of research and development assets acquired in transaction other than business combination or joint venture formation or both. Excludes write-down of intangible asset acquired in business combination or from joint venture formation or both, used in research and development activity. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 280 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 48 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482785/280-10-55-48 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 985 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481283/985-20-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 730 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482916/730-10-50-1 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 912 -SubTopic 730 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479532/912-730-25-1 + Details
Name: | us-gaap_ResearchAndDevelopmentExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=cara_NewCorporateHeadquartersOfficeSpaceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_ResearchAndDevelopmentExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_GeneralAndAdministrativeExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=cara_AssignmentOfNewLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=cara_StamfordOperatingLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=cara_PatheonMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=cara_NewStamfordLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=cara_NonExclusiveLicenseAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=cara_EnterisBiopharmaIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=cara_ManufacturingServicesAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CounterpartyNameAxis=cara_PatheonAndPatheonManufacturingServicesLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=cara_ApiCommercialSupplyAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=cara_ManufacturingServicesAgreementOrProductAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |