SEGMENT REPORTING - Operating Activity Within Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ 20,323	$ 30,384	$ 72,166	$ 83,692
Total segments’ profit	53,675	63,431	172,972	171,920
Office
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	44,821	42,810	133,210	100,816
Property Expenses	(11,595)	(11,627)	(34,989)	(29,385)
Operating Income (Loss)	33,226	31,183	98,221	71,431
Retail
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	20,621	25,848	67,939	81,156
Property Expenses	(7,795)	(7,806)	(20,033)	(22,691)
Operating Income (Loss)	12,826	18,042	47,906	58,465
Multifamily
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	12,564	12,655	37,852	38,451
Property Expenses	(5,603)	(5,367)	(16,426)	(15,323)
Operating Income (Loss)	6,961	7,288	21,426	23,128
Mixed-use
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	6,368	17,049	24,225	47,371
Property Expenses	(5,706)	(10,131)	(18,806)	(28,475)
Operating Income (Loss)	$ 662	$ 6,918	$ 5,419	$ 18,896