CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) $ in Millions	12 Months Ended
Dec. 31, 2023 USD ($)
CONSOLIDATED STATEMENTS OF CASH FLOWS
Approximate issuance costs related to royalty purchase and sale agreement	$ 1.0

The amount of issuance costs of royalty purchase and sale

No definition available.

Name:	cara_RoyaltyPurchaseAndSaleAgreementIssuanceCosts
Namespace Prefix:	cara_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration