Fair Value Measurements - Additional Information (Detail)	Jun. 30, 2022 USD ($)
Fair Value Disclosures [Abstract]
Transfers from Level 1 to Level 2 financial assets	$ 0
Transfers from Level 2 to Level 1 financial assets	$ 0

Fair Value Assets Level 1 To Level 2 Transfer Amount

No definition available.

Name:	ccxi_FairValueAssetsLevel1ToLevel2TransferAmount
Namespace Prefix:	ccxi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant