COMMITMENTS AND CONTINGENCIES, Purchase Commitments (Details) - USD ($) $ in Thousands	3 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Purchase Commitment [Abstract]
Percentage committed to be purchased	100.00%
Period of exclusive supply agreement	2 years
Purchase commitment in initial new order	$ 52,950
Remaining purchase commitment	41,490
Actual purchases under purchase amendment	2,490	$ 2,110
Minimum [Member]
Purchase Commitment [Abstract]
Future minimum annual purchase commitments	9,000
Maximum [Member]
Purchase Commitment [Abstract]
Future minimum annual purchase commitments	$ 12,000

Actual amount of purchases under purchase agreement during the reporting period.

No definition available.

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

- Definition

Represents the percentage committed to be purchased.

+ References

No definition available.

+ Details

Name:	cthr_PercentageCommittedToBePurchased
Namespace Prefix:	cthr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	cthr_PurchaseCommitmentAbstract
Namespace Prefix:	cthr_
Data Type:	xbrli:stringItemType
Balance Type:	na
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_RemainingLongTermPurchaseCommitmentAmountCommitted
Namespace Prefix:	cthr_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- 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_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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