Organization and Basis of Presentation (Details) - Jun. 30, 2017	Total	number_of_residential_units	tenant	ft²	project	property_units	building	property
Stabilized office properties [Member]
Real Estate Properties [Line Items]
Number of Buildings							111	4
Rentable Square Feet (unaudited)				14,394,534
Number of Tenants | tenant			543
Percentage Occupied (unaudited)	93.90%
Percentage Leased (unaudited)	96.00%
Stabilized residential properties [Member]
Real Estate Properties [Line Items]
Number of Buildings | building							1
Percentage Occupied (unaudited)	77.00%
Percentage Leased (unaudited)	82.00%
Number of Units | property_units						200
Development projects under construction [Member]
Real Estate Properties [Line Items]
Number of Buildings					4			3
Rentable Square Feet (unaudited)				1,800,000
Number of residential units | number_of_residential_units		237
Retail site [Member] | Development projects under construction [Member]
Real Estate Properties [Line Items]
Rentable Square Feet (unaudited)				96,000