SEGMENT REPORTING - Operating Activity Within Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
OPERATING INCOME	$ 12,920	$ 23,329
Total Segments' profit	51,766	46,397
Total Retail
Segment Reporting Information [Line Items]
Property revenue	26,157	24,791
Property expense	(6,811)	(6,691)
OPERATING INCOME	19,346	18,100
Total Office
Segment Reporting Information [Line Items]
Property revenue	26,770	25,990
Property expense	(8,013)	(7,801)
OPERATING INCOME	18,757	18,189
Total Multifamily
Segment Reporting Information [Line Items]
Property revenue	12,424	7,891
Property expense	(4,997)	(3,211)
OPERATING INCOME	7,427	4,680
Total Mixed-Use
Segment Reporting Information [Line Items]
Property revenue	15,381	15,120
Property expense	(9,145)	(9,692)
OPERATING INCOME	$ 6,236	$ 5,428