Basis of Presentation - Additional Information (Detail) - Jun. 30, 2014 - USD ($) $ in Thousands	Total	Total
Accounting Policies [Abstract]
Clinical compound revenue	$ 132	$ 159

Amount reclassified from collaborative revenue to clinical compound revenue.

No definition available.

Name:	cara_ClinicalCompoundRevenue
Namespace Prefix:	cara_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration