Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2020
Issuance of common stock in initial public offering, issuance costs		$ 199
Follow On Public Offering
Issuance of common stock in initial public offering, issuance costs	$ 7,259	$ 7,259

Issuance cost of common stock in initial public offering.

No definition available.

Name:	crnx_IssuanceCostOfCommonStockInInitialPublicOffering
Namespace Prefix:	crnx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration