Organization And Description Of Business (Narrative) (Details)	Sep. 30, 2012 property
Organization and Description of Business [Line Items]
Number of properties owned	110
Common Interest [Member]
Organization and Description of Business [Line Items]
Ownership percentage in the Operating Partnership	96.40%
Preferred Interest [Member]
Organization and Description of Business [Line Items]
Ownership percentage in the Operating Partnership	100.00%
Joint Ventures [Member]
Organization and Description of Business [Line Items]
Number of properties held as investments in unconsolidated joint ventures	3
North America [Member]
Organization and Description of Business [Line Items]
Number of properties owned	91
Europe [Member]
Organization and Description of Business [Line Items]
Number of properties owned	18
Asia [Member]
Organization and Description of Business [Line Items]
Number of properties owned	1