SEGMENT REPORTING - Operating Activity Within Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
OPERATING INCOME	$ 23,329	$ 23,643
Total Segments' profit	46,397	45,645
Total Retail
Segment Reporting Information [Line Items]
Property revenue	24,791	24,371
Property expense	(6,691)	(6,080)
OPERATING INCOME	18,100	18,291
Total Office
Segment Reporting Information [Line Items]
Property revenue	25,990	25,320
Property expense	(7,801)	(7,702)
OPERATING INCOME	18,189	17,618
Total Multifamily
Segment Reporting Information [Line Items]
Property revenue	7,891	6,294
Property expense	(3,211)	(2,820)
OPERATING INCOME	4,680	3,474
Total Mixed-Use
Segment Reporting Information [Line Items]
Property revenue	15,120	14,746
Property expense	(9,692)	(8,484)
OPERATING INCOME	$ 5,428	$ 6,262