Organization and Basis of Presentation Organization and Basis of Presentation (Details) ft² in Millions	Mar. 31, 2016 ft² properties
Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of properties	123
Percentage occupancy	96.20%
Unconsolidated Properties [Member] | Corporate Joint Venture [Member]
Real Estate Properties [Line Items]
Net Rentable Area | ft²	1.4
Retail Site [Member] | Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of properties	98
Retail Site [Member] | Unconsolidated Properties [Member] | Corporate Joint Venture [Member]
Real Estate Properties [Line Items]
Number of properties	6
Non-Retail Properties [Member] | Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of properties	5
Retail and Non-retail Properties [Member] | Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Net Rentable Area | ft²	12.2
Development and Redevelopment Properties [Member] | Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of properties	14
Net Rentable Area | ft²	3.0
Land Parcels [Member] | Wholly Owned Properties [Member]
Real Estate Properties [Line Items]
Number of properties	6
Office Buildings [Member] | Unconsolidated Properties [Member] | Corporate Joint Venture [Member]
Real Estate Properties [Line Items]
Number of properties	2