ACQUISITIONS (Details 2) (USD $)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2010	Nov. 09, 2010	Dec. 31, 2012	Dec. 31, 2011
Intangible assets and liabilities
Amortization of intangible assets and liabilities	$ 8,900,000	$ 1,700,000	$ 48,000,000	$ 60,600,000
Estimated decrease to income due to future amortization
2013			32,100,000
2014			23,300,000
2015			17,000,000
2016			12,700,000
2017			9,000,000
Tenant leases
Intangible assets and liabilities
Remaining amortization period			5 years
Tenant leases | In-place value
Intangible assets and liabilities
Gross Assets			97,887,000	101,425,000
Accumulated Amortization			(39,681,000)	(33,389,000)
Net Carrying Amount			58,206,000	68,036,000
Tenant leases | Acquired Above Market Lease Intangibles
Intangible assets and liabilities
Gross Assets			151,936,000	157,139,000
Accumulated Amortization			(62,529,000)	(40,464,000)
Net Carrying Amount			89,407,000	116,675,000
Tenant leases | Acquired Below Market Lease Intangibles
Intangible assets and liabilities
Gross Liability			(53,558,000)	(53,882,000)
Accumulated Accretion			18,490,000	13,762,000
Net Carrying Amount			(35,068,000)	(40,120,000)
Ground leases
Intangible assets and liabilities
Remaining amortization period			35 years
Ground leases | Acquired Below Market Lease Intangibles
Intangible assets and liabilities
Gross Assets			2,173,000	2,173,000
Accumulated Amortization			(267,000)	(142,000)
Net Carrying Amount			$ 1,906,000	$ 2,031,000