SEGMENT REPORTING Operating Activity Within Reportable Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
OPERATING INCOME	$ 19,373	$ 16,642	$ 39,253	$ 33,453
Total Segments' profit	40,752	34,882	81,846	70,272
Total Retail
Segment Reporting Information [Line Items]
Property revenue	23,497	22,452	45,651	44,143
Property expense	(6,060)	(6,094)	(11,031)	(11,820)
OPERATING INCOME	17,437	16,358	34,620	32,323
Total Office
Segment Reporting Information [Line Items]
Property revenue	22,512	18,027	44,934	35,914
Property expense	(6,584)	(5,858)	(13,020)	(11,376)
OPERATING INCOME	15,928	12,169	31,914	24,538
Total Multifamily
Segment Reporting Information [Line Items]
Property revenue	3,974	3,509	7,849	7,051
Property expense	(1,416)	(1,565)	(2,858)	(2,879)
OPERATING INCOME	2,558	1,944	4,991	4,172
Total Mixed-Use
Segment Reporting Information [Line Items]
Property revenue	12,931	12,143	26,660	24,472
Property expense	(8,102)	(7,732)	(16,339)	(15,233)
OPERATING INCOME	$ 4,829	$ 4,411	$ 10,321	$ 9,239