Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Intangible assets
Total Cost	$ 169,224	$ 196,147
Accumulated Amortization	(69,821)	(63,818)
Intangible Assets, net	99,403us-gaap_FiniteLivedIntangibleAssetsNet	132,329us-gaap_FiniteLivedIntangibleAssetsNet
Leases, Acquired-in-Place [Member]
Intangible assets
Total Cost	129,411	150,782
Accumulated Amortization	(42,068)	(35,607)
Intangible Assets, net	87,343	115,175
Tenant relationship value [Member]
Intangible assets
Total Cost	34,172	38,692
Accumulated Amortization	(26,344)	(26,868)
Intangible Assets, net	7,828	11,824
Above market leases acquired [Member]
Intangible assets
Total Cost	5,641	6,673
Accumulated Amortization	(1,409)	(1,343)
Intangible Assets, net	4,232	5,330
Below market leases acquired [Member]
Intangible assets
Total Cost	(53,049)	(81,991)
Accumulated Amortization	27,039	47,547
Intangible Assets, net	$ (26,010)	$ (34,444)

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=26713463&loc=d3e16323-109275

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- Definition

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

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