SEGMENT REPORTING - Capital Expenditures (Details) ft² in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016 USD ($) ft² unit	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) ft² unit	Jun. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Capital expenditures	[1]	$ 15,486	$ 46,542	$ 33,238	$ 91,510
Hassalo on Eighth - Residential
Segment Reporting Information [Line Items]
Number of units in real estate property | unit		657		657
Hassalo on Eighth - Retail
Segment Reporting Information [Line Items]
Net rentable area | ft²		47		47
Retail
Segment Reporting Information [Line Items]
Capital expenditures	[1]	$ 4,250	1,756	$ 9,664	2,691
Office
Segment Reporting Information [Line Items]
Capital expenditures	[1]	10,710	14,872	21,639	29,586
Multifamily
Segment Reporting Information [Line Items]
Capital expenditures	[1],[2]	475	29,748	1,819	58,696
Mixed-Use
Segment Reporting Information [Line Items]
Capital expenditures	[1]	$ 51	$ 166	$ 116	$ 537

[1] Capital expenditures represent cash paid for capital expenditures during the period and include leasing commissions paid.

[2] Multifamily capital expenditures include all capital expenditures incurred for the new development project Hassalo on Eighth, which consists of 657 multifamily units and approximately 47,000 square feet of retail space.