Summary of Significant Accounting Policies - Summary of Change in Allowance for Credit Losses (Details) $ in Thousands	6 Months Ended
Mar. 31, 2023 USD ($)
Receivables [Abstract]
Beginning balance	$ 371
Credit loss provision	3,626
Effect of foreign currency translation	140
Ending balance	$ 4,137

Accounts receivable and contract with customer assets allowance for credit loss effect of foreign currency translation.

No definition available.

Name:	crnc_AccountsReceivableAndContractWithCustomerAssetsAllowanceForCreditLossEffectOfForeignCurrencyTranslation
Namespace Prefix:	crnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration