Name:	chro_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantedInPeriodWeightedAverageRemainingLife
Namespace Prefix:	chro_
Data Type:	xbrli:durationItemType
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Period Type:	duration

The element represents weighted average remaining life end.

No definition available.

Name:	chro_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageRemainingLifeEnd
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Data Type:	xbrli:durationItemType
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Period Type:	duration

The element represents weighted average remaining life start.

No definition available.

Name:	chro_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageRemainingLifeStart
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Data Type:	xbrli:durationItemType
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- References

No definition available.

Name:	us-gaap_EquityAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Gross number of share options (or share units) granted during the period.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Number of options outstanding, including both vested and non-vested options.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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Data Type:	xbrli:sharesItemType
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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Data Type:	dtr-types:perShareItemType
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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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Data Type:	dtr-types:perShareItemType
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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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Data Type:	xbrli:durationItemType
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Number of share options (or share units) exercised during the current period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
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-Name Accounting Standards Codification
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-Paragraph 1
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1