ACQUISITIONS AND INTANGIBLES (Details 2) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Tenant leases, In-place value	Dec. 31, 2011 Tenant leases, In-place value	Jun. 30, 2012 Tenant leases, Above-market	Dec. 31, 2011 Tenant leases, Above-market	Jun. 30, 2012 Tenant leases, Below-market	Dec. 31, 2011 Tenant leases, Below-market	Jun. 30, 2012 Building leases, Above-market	Dec. 31, 2011 Building leases, Above-market	Jun. 30, 2012 Ground leases, Above-market	Dec. 31, 2011 Ground leases, Above-market	Jun. 30, 2012 Ground leases, Below-market	Dec. 31, 2011 Ground leases, Below-market	Jun. 30, 2012 Real estate tax stabilization agreement	Dec. 31, 2011 Real estate tax stabilization agreement
Finite-lived intangible assets and liabilities
Gross Asset (Liability)					$ 1,043,393,000	$ 1,252,484,000	$ 1,276,564,000	$ 1,478,798,000	$ (765,392,000)	$ (819,056,000)	$ (15,268,000)	$ (15,268,000)	$ (9,839,000)	$ (9,839,000)	$ 202,259,000	$ 204,432,000	$ 111,506,000	$ 111,506,000
Accumulated (Amortization)/ Accretion					(361,766,000)	(391,605,000)	(346,467,000)	(315,044,000)	204,398,000	184,254,000	2,545,000	1,697,000	631,000	439,000	(8,712,000)	(6,202,000)	(10,367,000)	(7,211,000)
Net Carrying Amount					681,627,000	860,879,000	930,097,000	1,163,754,000	(560,994,000)	(634,802,000)	(12,723,000)	(13,571,000)	(9,208,000)	(9,400,000)	193,547,000	198,230,000	101,139,000	104,295,000
Amortization/accretion effect on continuing operations	(86,755,000)	(122,918,000)	(192,587,000)	(242,133,000)
Future amortization, including company's share of items from unconsolidated real estate affiliates
Estimated decrease in net income due to amortization expense, remainder of 2012			172,200,000
Estimated decrease in net income due to amortization expense, 2013			285,300,000
Estimated decrease in net income due to amortization expense, 2014			233,700,000
Estimated decrease in net income due to amortization expense, 2015			191,300,000
Estimated decrease in net income due to amortization expense, 2016			$ 151,000,000