INVESTMENTS IN AND ADVANCES TO UNCONSOLIDATED AFFILIATES (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	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	$ 199,113		$ 199,113		$ 221,904
Payments to Acquire Equity Method Investments			54,207	19,356
Assets
Real estate under development	334,445		334,445		246,602
Investments in and advances to unconsolidated affiliates	199,113		199,113		221,904
Total assets	2,349,368	1,869,890	2,349,368	1,869,890	1,908,440
Liabilities and Equity
Other liabilities	16,318		16,318		14,207
Total liabilities and equity	2,349,368		2,349,368		1,908,440
Investments in and advances to unconsolidated affiliates	199,113		199,113		221,904
Company's share of distributions in excess of income from, and investments in, unconsolidated affiliates	(12,426)		(12,426)		(22,707)
Combined and Condensed Statements of Operations
Total revenues	40,318	28,831	121,891	81,033
Operating and other expenses	(27,517)	(21,733)	(78,408)	(62,321)
Equity in (losses) earnings of unconsolidated affiliates	4,209	(2,538)	7,274	1,997
Depreciation and amortization	(10,450)	(7,376)	(29,278)	(20,671)
Gain on sale of properties	0	5,917	4,191	8,585
Income (loss) from continuing operations	6,307	(1,421)	19,642	3,037
Unconsolidated Affiliates
Schedule of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	63,745		63,745		93,923
Assets
Rental property, net	365,399		365,399		441,611
Real estate under development	2,224		2,224		0
Investments in and advances to unconsolidated affiliates	63,745		63,745		93,923
Other assets	40,908		40,908		39,035
Total assets	472,276		472,276		574,569
Liabilities and Equity
Mortgage notes payable	241,907		241,907		326,296
Other liabilities	20,718		20,718		24,267
Partners' equity	209,651		209,651		224,006
Total liabilities and equity	472,276		472,276		574,569
Investments in and advances to unconsolidated affiliates	63,745		63,745		93,923
Combined and Condensed Statements of Operations
Total revenues	13,731	11,903	35,577	36,121
Operating and other expenses	(4,139)	(4,977)	(13,117)	(13,793)
Interest expense	(2,359)	(4,603)	(6,446)	(13,854)
Equity in (losses) earnings of unconsolidated affiliates	1,284	1,398	7,154	6,244
Depreciation and amortization	(3,200)	(2,573)	(7,888)	(7,216)
Gain on sale of properties	0	0	0	3,402
Income (loss) from continuing operations	5,317	1,148	15,280	10,904
Operating Partnership, as General Partner or Managing Member
Combined and Condensed Statements of Operations
Equity in (losses) earnings of unconsolidated affiliates	4,209	(2,538)	7,274	1,997
Company's share of net income (loss)	4,307	(2,440)	7,568	2,291
Amortization of excess investment	(98)	(98)	(294)	(294)
Core Portfolio
Assets
Total assets	993,472	605,694	993,472	605,694
Combined and Condensed Statements of Operations
Total revenues	28,115	17,794	82,252	50,166
Depreciation and amortization	(7,890)	(4,379)	(21,187)	(12,016)
Core Portfolio | Crossroads
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	49.00%		49.00%
Square Footage of Real Estate Property (in square feet)	311,000		311,000
Core Portfolio | Georgetown Portfolio
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	50.00%		50.00%
Square Footage of Real Estate Property (in square feet)	28,000		28,000
Core Portfolio | Route 202 Shopping Center [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	22.22%		22.22%
Square Footage of Real Estate Property (in square feet)	20,000		20,000
Opportunity Funds
Schedule of Equity Method Investments [Line Items]
Number of Unaffiliated Partners			2
Assets
Total assets	1,260,544	1,183,430	1,260,544	1,183,430
Combined and Condensed Statements of Operations
Total revenues	9,234	9,116	30,374	24,740
Depreciation and amortization	(2,560)	(2,997)	(8,091)	(8,655)
Opportunity Funds | RCP Venture
Schedule of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	63,214		63,214
Investment Income, Dividend			144,813
Assets
Investments in and advances to unconsolidated affiliates	63,214		63,214
Liabilities and Equity
Investments in and advances to unconsolidated affiliates	63,214		63,214
Opportunity Funds | RCP Venture | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Investments in and advances to unconsolidated affiliates	12,070		12,070
Investment Income, Dividend			31,146
Assets
Investments in and advances to unconsolidated affiliates	12,070		12,070
Liabilities and Equity
Investments in and advances to unconsolidated affiliates	12,070		12,070
Opportunity Funds | Mervyns I and Mervyns II | KLA/Mervyns LLC Add-On Investments
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	7,547		7,547
Investment Income, Dividend			5,334
Opportunity Funds | Mervyns I and Mervyns II | KLA/Mervyns LLC Add-On Investments | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	1,252		1,252
Investment Income, Dividend			1,193
Opportunity Funds | Mervyns II | KLA A Markets LLC Add-On Investments
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	2,416		2,416
Investment Income, Dividend			4,864
Opportunity Funds | Mervyns II | KLA A Markets LLC Add-On Investments | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	388		388
Investment Income, Dividend			972
Opportunity Funds | Mervyns II | KLAC Rex Venture LLC
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	2,701		2,701
Investment Income, Dividend			1,956
Opportunity Funds | Mervyns II | KLAC Rex Venture LLC | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	535		535
Investment Income, Dividend			392
Opportunity Funds | Fund II | KA-Shopko LLC
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	1,108		1,108
Investment Income, Dividend			2,460
Opportunity Funds | Fund II | KA-Shopko LLC | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	222		222
Investment Income, Dividend			492
Opportunity Funds | Fund II | Marsh and Add-On Investments
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	2,667		2,667
Investment Income, Dividend			2,639
Opportunity Funds | Fund II | Marsh and Add-On Investments | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Cost Method Investments	533		533
Investment Income, Dividend			528
Opportunity Funds | KLA/Mervyns LLC | Mervyns I and Mervyns II
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	26,058		26,058
Equity Method Investment, Dividends or Distributions			45,966
Opportunity Funds | KLA/Mervyns LLC | Mervyns I and Mervyns II | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	4,901		4,901
Equity Method Investment, Dividends or Distributions			11,251
Opportunity Funds | KLA A Markets LLC | Mervyns II
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	20,717		20,717
Equity Method Investment, Dividends or Distributions			81,594
Opportunity Funds | KLA A Markets LLC | Mervyns II | Operating Partnership, as General Partner or Managing Member
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	4,239		4,239
Equity Method Investment, Dividends or Distributions			16,318
Fund II
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments	1,100
Non-Cash Transfer of Prepaid Rent and Construction Costs to Acquire Equity Method Investments	$ 6,800