Organization and Significant Accounting Policies - Organization (Details)	6 Months Ended
Jun. 30, 2022 product
Organization and Summary of Significant Accounting Policies
Number of wholly-owned preclinical immuno-oncology programs	2
Product pipeline, number of drug candidates	4

Represents the number of drug candidates in the product pipeline.

No definition available.

Name:	chrs_ProductPipelineNumberOfDrugCandidates
Namespace Prefix:	chrs_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant