The Company (Details)	Dec. 31, 2011 states properties	Dec. 31, 2010 properties states
The Company [Abstract]
Number of Consolidated Properties	185	195
Number of States in which Entity has Interests	39	39

The number of states the entity operates in as of the balance sheet date.

No definition available.

Name:	us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant