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Basis of Presentation (Details Textual) | Dec. 31, 2011 | Dec. 31, 2010
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Basis of Presentation (Textual) [Abstract] |  |
Common ownership interest | 94.30% | 92.80%
Noncontrolling interest represents the aggregate partnership interest in the Operating Partnership held by the limited partners | 5.70% | 7.20%

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- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
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