Name:	cpt_CashRequiredByPlanParticipantsUponWithdrawal
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Common shares which could be granted pursuant to full value awards based on the 3.45 to 1.0 fungible unit-to-full value award conversion ratio.

No definition available.

Name:	cpt_CommonSharesWhichCouldBeGrantedPursuantToFullValueAwards
Namespace Prefix:	cpt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Maximum authorized purchase amount of shares during any plan year per participant for our employee share purchase plan.

No definition available.

Name:	cpt_EmployeeSharePurchasePlanMaximumAuthorizedAmountPerParticipant
Namespace Prefix:	cpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Employee Share Purchase Program maximum shares available under the 2018 ESPP Share plan

No definition available.

Name:	cpt_EmployeeSharePurchaseProgrammaximumsharesavailable
Namespace Prefix:	cpt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The full value award in the fungible unit to full value award conversion ratio regarding the shares from the 2002 share incentive plan transferred into the 2011 share incentive plan.

No definition available.

Name:	cpt_FullValueawardinthefungibleunitconversionratio
Namespace Prefix:	cpt_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

The award conversion ratio regarding the shares from the 2002 share incentive plan transferred into the 2011 share incentive plan.

No definition available.

Name:	cpt_FungibleUnitsToFullValueAwardConversionRatio
Namespace Prefix:	cpt_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

The percentage of market value per share at which shares may be purchased under our employee share purchase plan

No definition available.

Name:	cpt_PercentageOfMarketValueatWhichSharesPurchasedUnderEmployeeSharePurchasePlan
Namespace Prefix:	cpt_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The total amount of share awards held in a Rabbi Trust.

No definition available.

Name:	cpt_ShareAwardsHeldInEmployeeTrustShares
Namespace Prefix:	cpt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

The total amount of share awards held in a non-qualified deferred compensation plan.

No definition available.

Name:	cpt_ShareAwardsHeldInNonQualifiedDeferredCompensationPlanShares
Namespace Prefix:	cpt_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Equity-based compensation cost during the period with respect to the award, which was recognized in income.

No definition available.

Name:	cpt_ShareBasedCompensationArrangementByShareBasedPaymentAwardCompensationCostForPeriod
Namespace Prefix:	cpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Market value of trading securities held in a rabbi trust.

No definition available.

Name:	cpt_TradingSecuritiesHeldInEmployeeTrustValue
Namespace Prefix:	cpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Market value of trading securities held in a non-qualified deferred compensation plan.

No definition available.

Name:	cpt_TradingSecuritiesHeldInNonQualifiedDeferredCompensationPlanValue
Namespace Prefix:	cpt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

An option, right, or other award which does not deliver the full value at date of grant and expires five years or less from the date of grant counts against the Fungible Pool Limit as this portion of a fungible pool unit

No definition available.

Name:	cpt_ValueOfOptionRightOrOtherAwardInTheFungibleUnitConversion
Namespace Prefix:	cpt_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

Amount of cost for defined contribution plan.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480794/715-70-50-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of cost capitalized for award under share-based payment arrangement.

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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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