Fair Value Measurements (Narrative) (Details) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Non-recurring fair value measurements [Abstract]
Diversification of share awards within deferred compensation plan (Equity)	$ 951	$ 2,627	$ 23,200
Number of Operating properties Acquired	2

Non-qualified share awards diversified into other equity securities during the period.

No definition available.

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