Organization and Basis of Presentation (Narrative) (Details)	Dec. 31, 2011
Organization and Basis of Presentation [Abstract]
Ownership interest in operating partnership - Limited Partnership	96.80%

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant