Concentrations - Additional Information (Detail)	Sep. 30, 2012 State Property	Sep. 30, 2011 Property State
Information About Revenue And Geographic Areas [Line Items]
Number of consolidated properties	78	74
Number of states in which consolidated properties located	17	14

Number of states in which consolidated properties located.

No definition available.

Name:	ck0001297587_NumberOfStatesInWhichConsolidatedPropertiesLocated
Namespace Prefix:	ck0001297587_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant