Summary of Significant Accounting Policies - Summary of Change in Allowance for Credit Losses (Details) $ in Thousands	6 Months Ended
Mar. 31, 2024 USD ($)
Receivables [Abstract]
Beginning balance	$ 4,131
Credit loss provision	6,065
Write-offs, net of recoveries	(6,065)
Effect of foreign currency translation	4
Ending balance	$ 4,135

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