SEGMENT REPORTING - Capital Expenditures (Details) ft² in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016 USD ($) ft² unit	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) ft² unit	Sep. 30, 2015 USD ($)
Segment Reporting Information [Line Items]
Capital expenditures	[1]	$ 14,153	$ 26,888	$ 47,391	$ 118,398
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]	$ 2,203	2,544	$ 11,867	5,235
Office
Segment Reporting Information [Line Items]
Capital expenditures	[1]	11,637	7,616	33,276	37,202
Multifamily
Segment Reporting Information [Line Items]
Capital expenditures	[1],[2]	213	16,678	2,032	75,374
Mixed-Use
Segment Reporting Information [Line Items]
Capital expenditures	[1]	$ 100	$ 50	$ 216	$ 587

[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.