SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of Reportable Segments	3
Revenues	$ 47,271	$ 29,913
Property operating expenses, other operating and real estate taxes	12,345	9,596
General and administrative	5,626	5,925
Income before depreciation and amortization and interest and other finance expense	29,300	14,392
Depreciation and amortization	10,628	7,146
Interest and other finance expense	10,309	6,560
Real estate at cost	1,767,176	1,190,604
Total assets	2,295,869	1,372,433	1,908,440
Expenditures for redevelopment and improvements	17,941	20,081
Acquisition of real estate	86,600	48,689
Other interest income	29	54
Income (Loss) from Equity Method Investments	2,250	(56)
Income tax provision	140	(188)
Operating income from discontinued operations	397	2,327
Net income	11,179	2,823
Net income attributable to noncontrolling interests	(1,556)	1,187
Net income attributable to Common Shareholders	9,623	4,010
Core Portfolio
Segment Reporting Information [Line Items]
Revenues	26,877	15,708
Property operating expenses, other operating and real estate taxes	7,163	4,532
General and administrative	5,481	5,651
Income before depreciation and amortization and interest and other finance expense	14,233	5,525
Depreciation and amortization	6,636	3,742
Interest and other finance expense	6,149	3,358
Real estate at cost	979,553	548,075
Total assets	1,075,253	661,545
Expenditures for redevelopment and improvements	456	7,204
Acquisition of real estate	86,600	16,189
Opportunity Funds
Segment Reporting Information [Line Items]
Revenues	17,525	12,150
Property operating expenses, other operating and real estate taxes	5,182	5,064
General and administrative	145	274
Income before depreciation and amortization and interest and other finance expense	12,198	6,812
Depreciation and amortization	3,992	3,404
Interest and other finance expense	4,160	3,202
Real estate at cost	787,623	642,529
Total assets	1,115,249	633,708
Expenditures for redevelopment and improvements	17,485	12,877
Acquisition of real estate	0	32,500
Notes Receivable
Segment Reporting Information [Line Items]
Revenues	2,869	2,055
Property operating expenses, other operating and real estate taxes	0	0
General and administrative	0	0
Income before depreciation and amortization and interest and other finance expense	2,869	2,055
Depreciation and amortization	0	0
Interest and other finance expense	0	0
Real estate at cost	0	0
Total assets	105,367	77,180
Expenditures for redevelopment and improvements	0	0
Acquisition of real estate	$ 0	$ 0