Acquisitions (Narratives) (Details) (New York Segment [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended
Dec. 31, 2013 Retail Properties [Member] Manhattan [Member] Properties sqft	Oct. 04, 2013 New York 655 Fifth Avenue [Member] sqft	Oct. 15, 2013 New York Manhattan 220 Central Park South Site [Member] sqft
Business Acquisition [Line Items]
Ownership Percentage Interest Acquired		92.50%
Square Footage Of Real Estate Property	2,400,000	57,500	137,000
Cost Of Acquired Entity Purchase Price	$ 65,300	$ 277,500	$ 194,000
Number of retail properties acquired	3

The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant