Area of a real estate property subject to lease.

No definition available.

Name:	cara_AreaOfRealEstatePropertySubjectToLease
Namespace Prefix:	cara_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount by which the face amount of the letters of credit that can be reduced on each of the first or second anniversaries of the rent commencement date if the Company is not in default of its lease obligations.

+ References

No definition available.

+ Details

Name:	cara_LetterOfCreditReducedAmount
Namespace Prefix:	cara_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

+ Details

Name:	us-gaap_RestrictedCashAndCashEquivalentsItemsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

+ Details

Name:	us-gaap_RestrictedCashCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cash restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 5
-SubTopic 210
-Topic 954
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480632/954-210-45-5

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482913/230-10-50-8

+ Details

Name:	us-gaap_RestrictedCashNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=cara_NewStamfordLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsAxis=cara_MoneyMarketFundForStamfordLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Restricted Cash - Additional Information (Detail) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	May 31, 2023 ft²
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash, current assets		$ 408
Restricted cash, long-term assets	$ 1,500	1,500
New Stamford Lease [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Lease for office space area (square feet) \| ft²			26,374
Restricted cash, long-term assets	1,500	1,500
Letters of credit, face amount that can be reduced	$ 500
Old Stamford Lease [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash, current assets		$ 408