Acquired Intangible Assets And Liabilities (Summary Of Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Acquired In Place Lease Value [Member]
Finite-Lived Intangible Assets [Line Items]
Gross amount	$ 727,521	$ 720,373
Accumulated amortization	(396,284)	(367,088)
Net	331,237	353,285
Acquired Above-Market Lease Value [Member]
Finite-Lived Intangible Assets [Line Items]
Gross amount	131,596	134,480
Accumulated amortization	(75,286)	(69,425)
Net	56,310	65,055
Acquired Below-Market Lease Value [Member]
Finite-Lived Intangible Assets [Line Items]
Gross amount	286,318	285,509
Accumulated amortization	(149,021)	(137,276)
Net	$ 137,297	$ 148,233

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7658586&loc=d3e16323-109275

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant