Real Estate (Significant Acquisitions and Dispositions) (Details) $ in Thousands											3 Months Ended			6 Months Ended	12 Months Ended			24 Months Ended
	Nov. 07, 2016 USD ($)	Jul. 26, 2016 USD ($)	May 12, 2016 USD ($)	Jan. 13, 2016 USD ($) property	Nov. 19, 2015 USD ($)	Oct. 01, 2015 USD ($) ft²	Jul. 08, 2015 USD ($)	May 04, 2015 USD ($) ft²	Apr. 24, 2015 USD ($)	Jan. 09, 2015 USD ($) ft² shares	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 16, 2015 USD ($) building	Dec. 31, 2016 USD ($) project	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 USD ($) project	Dec. 31, 2015 USD ($)	Feb. 25, 2015 USD ($)
Business Acquisition and Disposition
Mortgage loans assumed with acquisition															$ 34,385	$ 89,516	$ 68,282
Number of real estate properties | project															96			96
Contributions from noncontrolling interests															$ 885	34,737	$ 65,350
Houston Street
Business Acquisition and Disposition
Proceeds from sale									$ 46,100
Gain on sale of real estate									$ 11,500				$ 11,500
Courtyard Shops
Business Acquisition and Disposition
Proceeds from sale					$ 52,800
Gain on sale of real estate					$ 16,800							$ 16,800
Clarion
Business Acquisition and Disposition
Ownership percentage in partnership				70.00%
Purchase Price				$ 153,700
Cash paid in acquisition				130,000
Mortgage loans assumed with acquisition				$ 34,400
Number of real estate properties | property				6
Gain on acquisition of controlling interest				$ 25,700							$ 25,700
A building adjacent to our Barcroft Plaza property
Business Acquisition and Disposition
Purchase Price	$ 5,300
San Antonio Center
Business Acquisition and Disposition
Square footage of real estate property | ft²										376,000
Gross value										$ 62,200
Effective interest percentage										80.00%
Number of downREIT Operating Partnership Units Issued in Connection with Business Acquisition | shares										58,000
Cash paid in acquisition										$ 27,000
Mortgage loans assumed with acquisition										18,700
Contributions from noncontrolling interests										16,300
CocoWalk
Business Acquisition and Disposition
Square footage of real estate property | ft²								198,000
Purchase Price								$ 87,500
Common interest percentage								80.00%
Contributions from noncontrolling interests								$ 6,900
The Shops at Sunset Place
Business Acquisition and Disposition
Square footage of real estate property | ft²						515,000
Purchase Price						$ 110,200
Mortgage loans assumed with acquisition						$ 70,800
Ownership interest						85.00%
Contributions from noncontrolling interests						$ 6,300
Other Liabilities | Clarion
Business Acquisition and Disposition
Net assets acquired allocated to below market leases				4,900
Other Liabilities | San Antonio Center
Business Acquisition and Disposition
Net assets acquired allocated to below market leases										19,100
Other Liabilities | CocoWalk
Business Acquisition and Disposition
Net assets acquired allocated to below market leases								4,300
Other Liabilities | The Shops at Sunset Place
Business Acquisition and Disposition
Net assets acquired allocated to below market leases						6,600
Other Assets | Above Market Leases | Clarion
Business Acquisition and Disposition
Net assets acquired allocated to above market leases				$ 7,300
Other Assets | Above Market Leases | San Antonio Center
Business Acquisition and Disposition
Net assets acquired allocated to above market leases										$ 8,100
Other Assets | Above Market Leases | CocoWalk
Business Acquisition and Disposition
Net assets acquired allocated to above market leases								$ 1,500
Other Assets | Above Market Leases | The Shops at Sunset Place
Business Acquisition and Disposition
Net assets acquired allocated to above market leases						$ 4,800
General and Administrative Expense | Clarion
Business Acquisition and Disposition
Acquisition costs															100			$ 200
General and Administrative Expense | A building adjacent to our Barcroft Plaza property
Business Acquisition and Disposition
Acquisition costs															100
General and Administrative Expense | San Antonio Center
Business Acquisition and Disposition
Acquisition costs																1,100			$ 1,800
General and Administrative Expense | CocoWalk
Business Acquisition and Disposition
Acquisition costs																1,100
General and Administrative Expense | The Shops at Sunset Place
Business Acquisition and Disposition
Acquisition costs																$ 900
CocoWalk | Coconut Grove
Business Acquisition and Disposition
Gain on sale of real estate, net of noncontrolling interests			$ 500
CocoWalk | Coconut Grove
Business Acquisition and Disposition
Purchase Price		$ 5,900												$ 7,800
Number Of Buildings | building														8
CocoWalk | General and Administrative Expense | Coconut Grove
Business Acquisition and Disposition
Acquisition costs															$ 200
Land | Pike Seven Plaza
Business Acquisition and Disposition
Purchase Price							$ 5,000
The Grove at Shrewsbury (East)
Business Acquisition and Disposition
Price to acquire noncontrolling interest																				$ 8,800