Description of Business (Details)	Sep. 30, 2017
Business Acquisition [Line Items]
Number of multifamily properties owned, operated, or under development	162
Total number of apartment homes in multifamily properties	55,877
Number of multifamily properties under development	6
Total Number of apartment homes in multifamily properties upon completion of development	1,839

- Definition

The total number of real estate properties the company owned interests in, operated, or were developing as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cpt_NumberOfMultifamilyCommunities
Namespace Prefix:	cpt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of real estate properties under development the company owned interests in or fully owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cpt_NumberOfMultifamilyPropertiesUnderDevelopment
Namespace Prefix:	cpt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The total number of units in real estate properties the company owned interests in, operated, or were developing as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cpt_TotalNumberOfApartmentHomesInMultifamilyCommunities
Namespace Prefix:	cpt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of units in the real estate properties under development the company owned interests in or fully owned as of the balance sheet date which will be added upon completion of development.

+ References

No definition available.

+ Details

Name:	cpt_TotalNumberOfApartmentHomesInMultifamilyPropertiesUponCompletionOfDevelopment
Namespace Prefix:	cpt_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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