SEGMENT REPORTING Net Real Estate and Secured Note Payable Balances (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Segment Reporting Information [Line Items]
Net Real Estate	$ 1,692,929		$ 1,676,836
Secured Notes Payable	961,855	[1]	962,259	[1]
Unamortized fair value adjustment	9,357		10,085
Total Retail
Segment Reporting Information [Line Items]
Net Real Estate	647,816		651,707
Secured Notes Payable	303,101	[1]	303,249	[1]
Total Office
Segment Reporting Information [Line Items]
Net Real Estate	811,097		790,153
Secured Notes Payable	427,000	[1]	427,256	[1]
Total Multifamily
Segment Reporting Information [Line Items]
Net Real Estate	34,984		35,349
Secured Notes Payable	101,444	[1]	101,444	[1]
Total Mixed-Use
Segment Reporting Information [Line Items]
Net Real Estate	199,032		199,627
Secured Notes Payable	$ 130,310	[1]	$ 130,310	[1]

[1] Excludes unamortized fair market value adjustments of $9.4 million and $10.1 million as of March 31, 2014 and December 31, 2013, respectively.