Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Intangible Assets [Line Items]
Total Cost	$ 179,527	$ 196,147
Accumulated Amortization	(67,387)	(63,818)
Intangible Assets, net	112,140	132,329
In-place lease value
Intangible Assets [Line Items]
Total Cost	136,388	150,782
Accumulated Amortization	(38,767)	(35,607)
Intangible Assets, net	97,621	115,175
Tenant relationship value
Intangible Assets [Line Items]
Total Cost	37,019	38,692
Accumulated Amortization	(27,159)	(26,868)
Intangible Assets, net	9,860	11,824
Above market leases acquired
Intangible Assets [Line Items]
Total Cost	6,120	6,673
Accumulated Amortization	(1,461)	(1,343)
Intangible Assets, net	4,659	5,330
Below Market Leases Acquired [Member]
Intangible Assets [Line Items]
Total Cost	(64,679)	(81,991)
Accumulated Amortization	35,563	47,547
Intangible Assets, net	$ (29,116)	$ (34,444)