SEGMENT REPORTING Operating Activity Within Reportable Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
OPERATING INCOME	$ 21,441	$ 18,205	$ 60,694	$ 51,658
Total Segments' profit	42,120	38,193	123,966	108,465
Total Retail
Segment Reporting Information [Line Items]
Property revenue	23,524	23,694	69,175	67,837
Property expense	(6,445)	(6,828)	(17,476)	(18,648)
OPERATING INCOME	17,079	16,866	51,699	49,189
Total Office
Segment Reporting Information [Line Items]
Property revenue	22,664	19,586	67,598	55,500
Property expense	(6,636)	(6,054)	(19,656)	(17,430)
OPERATING INCOME	16,028	13,532	47,942	38,070
Total Multifamily
Segment Reporting Information [Line Items]
Property revenue	4,155	3,906	12,004	10,957
Property expense	(1,525)	(1,558)	(4,383)	(4,437)
OPERATING INCOME	2,630	2,348	7,621	6,520
Total Mixed-Use
Segment Reporting Information [Line Items]
Property revenue	14,975	13,579	41,635	38,051
Property expense	(8,592)	(8,132)	(24,931)	(23,365)
OPERATING INCOME	$ 6,383	$ 5,447	$ 16,704	$ 14,686