Revenue Recognition - Schedule of Customer Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2021	Mar. 31, 2021
Customer Contract Liabilities
Beginning balance	$ 54,177	$ 51,369
Quarterly additions	19,501	19,303
Revenue recognized from the prior periods	(13,605)	(12,603)
Revenue recognized from current quarter additions	(4,639)	(4,551)
Deferred revenue from acquisition		659
Other adjustments	(3,146)
Ending balance	$ 52,288	$ 54,177

Contract with customer liability deferred revenue from acquisition.

No definition available.

Name:	crda_ContractWithCustomerLiabilityDeferredRevenueFromAcquisition
Namespace Prefix:	crda_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with customer, liability, increase from cash receipts.

+ References

No definition available.

+ Details

Name:	crda_ContractWithCustomerLiabilityIncreaseFromCashReceipts
Namespace Prefix:	crda_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with customer liability other adjustments.

+ References

No definition available.

+ Details

Name:	crda_ContractWithCustomerLiabilityOtherAdjustments
Namespace Prefix:	crda_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with customer, liability, revenue recognized that was not previously included in balance of obligation.

+ References

No definition available.

+ Details

Name:	crda_ContractWithCustomerLiabilityRevenueRecognizedThatWasNotPreviouslyIncludedInBalanceOfObligation
Namespace Prefix:	crda_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130531-203044

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121556615&loc=SL49130532-203044

+ Details

Name:	us-gaap_ContractWithCustomerLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

+ Details

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

Name:	us-gaap_MovementInDeferredRevenueRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration