Revenue Recognition - Summary of Significant Changes in Contract Assets (Details) $ in Thousands	3 Months Ended
Dec. 31, 2025 USD ($)
Contract assets
Beginning balance	$ 13,978
Revenues recognized but not billed	7,555
Amounts reclassified to Accounts receivable, net	(9,723)
Effect of foreign currency translation	(291)
Ending balance	$ 11,519

Contract with Customer, Asset, after Allowance for Credit Loss

No definition available.

Name:	crnc_ContractWithCustomerAssetAfterAllowanceForCreditLossRollForward
Namespace Prefix:	crnc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contract With customer asset amount recognized but unbilled

+ References

No definition available.

+ Details

Name:	crnc_ContractWithCustomerAssetAmountRecognizedButUnbilled
Namespace Prefix:	crnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Contract with customer asset effect of foreign currency translation.

+ References

No definition available.

+ Details

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

- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479837/606-10-45-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-8

+ Details

Name:	us-gaap_ContractWithCustomerAssetNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of decrease in right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time from transfer to receivable due to right to consideration becoming unconditional.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-10

+ Details

Name:	us-gaap_ContractWithCustomerAssetReclassifiedToReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration