Intangibles Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Assets
Gross	$ 473,795	$ 408,858
Accumulated amortization	(150,207)	(125,924)
Total	323,588	282,934
Weighted average remaining amortization period in years	15 years 10 months 24 days	15 years 10 months 24 days
Liabilities
Gross	17,816	16,650
Accumulated amortization	(6,019)	(5,341)
Total	11,797	11,309
Weighted average remaining amortization period in years	18 years 4 months 24 days	19 years 6 months
Below Market Leases
Liabilities
Gross	13,989	12,823
Weighted average remaining amortization period in years	12 years 4 months 24 days	13 years 8 months 12 days
Above Market Leasehold Interests
Liabilities
Gross	3,827	3,827
Weighted average remaining amortization period in years	33 years 1 month 6 days	34 years
In Place Leases
Assets
Gross	212,142	174,615
Weighted average remaining amortization period in years	8 years 9 months 18 days	9 years 8 months 12 days
Tenant Relationships
Assets
Gross	197,214	178,269
Weighted average remaining amortization period in years	10 years 6 months	11 years 7 months 6 days
Above Market Leases
Assets
Gross	26,799	25,387
Weighted average remaining amortization period in years	6 years 3 months 18 days	6 years 10 months 24 days
Below Market Leasehold Interests
Assets
Gross	$ 37,640	$ 30,587
Weighted average remaining amortization period in years	68 years 10 months 24 days	69 years 4 months 24 days