Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Intangible Assets [Line Items]
Total Cost	$ 191,938	$ 196,147
Accumulated Amortization	(66,776)	(63,818)
Intangible Assets, net	125,162	132,329
In-place lease value
Intangible Assets [Line Items]
Total Cost	147,606	150,782
Accumulated Amortization	(38,327)	(35,607)
Intangible Assets, net	109,279	115,175
Tenant relationship value
Intangible Assets [Line Items]
Total Cost	37,671	38,692
Accumulated Amortization	(26,858)	(26,868)
Intangible Assets, net	10,813	11,824
Above market leases acquired
Intangible Assets [Line Items]
Total Cost	6,661	6,673
Accumulated Amortization	(1,591)	(1,343)
Intangible Assets, net	5,070	5,330
Below Market Leases Acquired [Member]
Intangible Assets [Line Items]
Total Cost	(81,847)	(81,991)
Accumulated Amortization	49,618	47,547
Intangible Assets, net	$ (32,229)	$ (34,444)