The minimum amount the entity agreed to spend under the long-term purchase commitment.

No definition available.

Name:	cthr_LongTermPurchaseCommitmentCommittedAmount
Namespace Prefix:	cthr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Term of long-term purchase commitment extension, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	cthr_LongTermPurchaseCommitmentExtensionTerm
Namespace Prefix:	cthr_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of options to extend the term of the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	cthr_LongTermPurchaseCommitmentNumberOfOptionsToExtendTerm
Namespace Prefix:	cthr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of purchases made under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	cthr_LongTermPurchaseCommitmentPurchases
Namespace Prefix:	cthr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The remaining minimum amount the entity agreed to spend under the long-term purchase commitment.

+ References

No definition available.

+ Details

Name:	cthr_LongTermPurchaseCommitmentRemainingCommittedAmount
Namespace Prefix:	cthr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Estimated amount of purchases of SiC crystals not paid for under the Supply Agreement.

+ References

No definition available.

+ Details

Name:	cthr_LossContingencyEstimateOfUnpaidPurchases
Namespace Prefix:	cthr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of required SiC materials committed to be purchased.

+ References

No definition available.

+ Details

Name:	cthr_PercentageOfMaterialsCommittedToBePurchased
Namespace Prefix:	cthr_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482425/460-10-50-3

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483076/450-20-50-4

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 450
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483076/450-20-50-9

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482425/460-10-50-2

+ Details

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

- Definition

Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_LitigationCaseAxis=cthr_BreachOfContractForPurchaseOfSiCMaterialsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=cthr_SicMaterialsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
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COMMITMENTS AND CONTINGENCIES, Purchase Commitments (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($) Option	Jun. 30, 2022 USD ($)	Jul. 28, 2023 USD ($)
Breach of Contract for Purchase of SiC Materials [Member]
Purchase Commitments [Abstract]
Alleged unpaid purchases	$ 3,300	$ 3,300
Breach of Contract for Purchase of SiC Materials [Member] \| Subsequent Event [Member]
Purchase Commitments [Abstract]
Alleged damages				$ 18,500
SiC Materials [Member]
Purchase Commitments [Abstract]
Percentage of materials committed to be purchased		100.00%
Number of options to extend term of exclusive supply agreement \| Option		1
Extension period of exclusive supply agreement		2 years
Total purchase commitment	52,950	$ 52,950
Remaining purchase commitment	24,750	24,750
Minimum annual purchase commitments	4,250	4,250
Purchases	0	1,800	$ 6,290
SiC Materials [Member] \| Minimum [Member]
Purchase Commitments [Abstract]
Minimum annual purchase commitments	4,000	4,000
SiC Materials [Member] \| Maximum [Member]
Purchase Commitments [Abstract]
Minimum annual purchase commitments	$ 10,000	$ 10,000