SEGMENT REPORTING Net Real Estate and Secured Note Payable Balances (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Segment Reporting Information [Line Items]
Net Real Estate	$ 1,738,039		$ 1,676,836
Secured Notes Payable	961,090	[1]	962,259	[1]
Unamortized fair value adjustment	7,900		10,085
Total Retail
Segment Reporting Information [Line Items]
Net Real Estate	641,406		651,707
Secured Notes Payable	302,823	[1]	303,249	[1]
Total Office
Segment Reporting Information [Line Items]
Net Real Estate	754,608		750,890
Secured Notes Payable	426,513	[1]	427,256	[1]
Total Multifamily
Segment Reporting Information [Line Items]
Net Real Estate	146,302		74,612
Secured Notes Payable	101,444	[1]	101,444	[1]
Total Mixed-Use
Segment Reporting Information [Line Items]
Net Real Estate	195,723		199,627
Secured Notes Payable	$ 130,310	[1]	$ 130,310	[1]

[1] Excludes unamortized fair market value adjustments of $7.9 million and $10.1 million as of September 30, 2014 and December 31, 2013, respectively.