SEGMENT REPORTING - Operating Activity Within Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ 22,995	$ 24,487	$ 51,843	$ 53,308
Total segments’ profit	56,167	53,012	119,297	108,489
Office
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	43,880	30,200	88,389	58,006
Property Expenses	(11,601)	(9,269)	(23,394)	(17,758)
Operating Income (Loss)	32,279	20,931	64,995	40,248
Retail
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	21,492	25,871	47,318	55,308
Property Expenses	(4,907)	(7,731)	(12,238)	(14,885)
Operating Income (Loss)	16,585	18,140	35,080	40,423
Multifamily
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	12,463	12,897	25,288	25,796
Property Expenses	(5,313)	(4,883)	(10,823)	(9,956)
Operating Income (Loss)	7,150	8,014	14,465	15,840
Mixed-use
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,274	15,145	17,857	30,322
Property Expenses	(4,121)	(9,218)	(13,100)	(18,344)
Operating Income (Loss)	$ 153	$ 5,927	$ 4,757	$ 11,978